Article

P-Wave Indices, Distribution and Quality Control Assessment (from the Framingham Heart Study)

January 2010
Annals of Noninvasive Electrocardiology 15(1):77-84

DOI:10.1111/j.1542-474X.2009.00343.x

Source
PubMed

Authors:

Jared W Magnani

Boston University

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P-wave indices of maximum P-wave duration and P-wave dispersion have been examined in a broad array of cardiovascular and noncardiovascular disease states. The P-wave indices literature has been highly heterogeneous in measurement methodologies, described quality control metrics, and distribution of values. We therefore sought to determine the reproducibility of P-wave indices in a community-based cohort. P-wave indices were measured in sequential subjects enrolled in the Framingham Heart Study. Electrocardiograms were obtained at the 11th biennial visit of the Original Cohort (n = 250) and the initial visit of the Offspring Cohort (n = 252). We determined the mean P-wave durations, interlead correlations, and P-wave indices. We then chose 20 ECGs, 10 from each cohort, and assessed intrarater and interrater variability. The maximum P-wave duration ranged from 71 to 162 ms with mean of 112 + or - 12 ms. The minimum P-wave duration ranged from 35 to 103 ms with mean of 65 + or - 10 ms. P-wave dispersion ranged from 12 to 82 ms. The mean P-wave dispersion was 48 + or - 12 ms (40-56). The intrarater intraclass correlation coefficient (ICC) was r = 0.80 for maximum P-wave duration and r = 0.82 for P-wave dispersion. The interrater ICC was 0.56 for maximum P-wave duration and 0.70 for P-wave dispersion. We demonstrated excellent intrarater reproducibility and fair interrater reproducibility for calculating P-wave indices. Reproducibility is frequently lacking in studies of P-wave indices, but is an essential component for the field's growth and epidemiologic contribution.

Correlation among P wave dispersion and cardiac arrhythmias and alterations of the conduction system in patients with arterial hypertension from the Hospital de Clinicas, Asunción, Paraguay

Article

Full-text available

Jun 2019

Introducción: La hipertensión arterial puede producir cambios auriculares que generan arritmias auriculares. La dispersión de la onda P (PWD) se considera un marcador electrocardiográfico no invasivo para la remodelación auricular y un predictor para el desarrollo de fibrilación auricular. Nuestro objetico es estudiar la correlación entre la dispersión de la onda P con las arritmias cardíacas y los trastornos del sistema de conducción en pacientes con hipertensión arterial (HTA). Metodología: Estudio observacional y prospectivo en el que estudiamos las variaciones electrocardiográficas, mediciones ecocardiográficas y Holter ECG de 24 hs en pacientes hipertensos que acuden a un hospital terciario desde marzo del 2018 a septiembre del 2018 en forma ambulatoria y a internados. Resultados: Se estudiaron 104 pacientes, 65 hipertensos conocidos y 39 no hipertensos como grupo control. El valor promedio de la dispersión de la onda P en hipertensos fue de 37±8 ms, y en el grupo control fue de 27±13 ms, P <0,001. Además se encontró una diferencia significativa entre estos dos grupos en la duración máxima de la onda P (p<0,05), y el diámetro de la aurícula izquierda (p<0,05). La PWD posee una especificidad de 72% y un valor predictivo negativo de 78% relacionado con la presencia de trastornos del sistema de conducción y arritmias cardiacas en pacientes con HTA. Además, la PWD posee una especificidad de 73% y un valor predictivo negativo de 83% relacionado con la presencia de ensanchamiento del complejo QRS. Conclusiones: Existe una mayor alteración significativa en la dispersión de la Onda P, la Onda P máxima, y la dilatación de la aurícula izquierda en HTA. También se observó una correlación significativa entre la dispersión de la onda P y el riesgo de desarrollar arritmias auriculares. La dispersión de la onda P tiene una elevada especificidad y un alto valor predictivo negativo en la detección de la presencia de prolongación del intervalo QT, ensanchamiento del complejo QRS, dilatación de la aurícula izquierda y trastornos del sistema de conducción y arritmias cardiacas en pacientes con hipertensión arterial.

Type 2 myocardial infarction in patients with coronavirus disease 2019

Article

Nov 2020

Reduction in acute coronary syndromes during coronavirus disease 2019 global pandemic: data from the Marche region of Italy

Article

Oct 2020
J CARDIOVASC MED

Aims: During the novel severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019) pandemic, a worldwide reduction in total acute coronary syndrome (ACS) has been reported. In early 2020, Italy became the most affected country and national lockdown was declared early on in March. We described trends in ACS from all the Marche coronary catheterization laboratories (CCL) during the global pandemic. Methods: Retrospective study of all consecutive patients admitted to the four regional CCL. The coronavirus disease 2019 period (20 February 2020 to 15 April 2020) was compared with the interyear control period (1 January 2020 to 19 February 2020) and to the intrayear control period (20 February 2019 to 15 April 2019). All patients with an initial diagnosis of ACS were included in the analysis, and further stratified into ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI)/unstable angina. Results: A total of 1239 patients were enrolled. Daily incidence of ACS was 6.1, 6.3 and 4.5 for the interyear control period, the intrayear control period and the case period, respectively. There was no difference in overall STEMI daily incidence while NSTEMI/unstable angina fell from 3.6 and 3.3-1.8 during the case period (P = 0.01). Incidence rate ratios were significantly lower when the case period was compared with the intrayear control period (incidence rate ratios: 0.49, 95% confidence interval 0.41-0.59, P = 0.001) and the interyear control period (incidence rate ratios: 0.67, 95% confidence interval 0.50-0.90, P = 0.008). Conclusion: During the global pandemic there was a significant reduction in total ACS and NSTEMI in the Marche region. Unlike previous reports, there was no difference in overall access to CCL for STEMI during the same period.

Evaluation of P-wave dispersion in patients with newly diagnosed coronavirus disease 2019

Article

Nov 2020
J CARDIOVASC MED

Aim: The aim of the current study was to evaluate P-wave dispersion (PWD) as a predictor of atrial fibrillation in patients with newly diagnosed COVID-19. In addition, the relationship between the PWD and inflammation parameters was investigated. Methods: A total of 140 newly diagnosed COVID-19 patients and 140 age- and sex-matched healthy individuals were included in the study. The risk of atrial fibrillation was evaluated by calculating the electrocardiographic PWD. C-reactive protein (CRP), white blood cell, neutrophil and neutrophil-to-lymphocyte ratio (NLR) were measured in patients with newly diagnosed COVID-19. Results: PWD, white blood cell, NLR and CRP levels were significantly higher in the COVID-19 group than the control group. There was a significant positive correlation between PWD and CRP level (rs = 0.510, P < 0.001) and NLR in COVID-19 group (rs = 0.302, P = 0.001). In their follow-up, 13 (9.3%) patients, 11 of whom were in the ICU, developed new atrial fibrillation. Conclusion: Our study showed for the first time in literature that the PWD, evaluated electrocardiographically in patients with newly diagnosed COVID-19, was prolonged compared with normal healthy individuals. A positive correlation was found between PWD, CRP level and NLR. We believe that pretreatment evaluation of PWD in patients with newly diagnosed COVID-19 would be beneficial for predicting atrial fibrillation risk.

Relation of atrial electromechanical delay to P-wave dispersion on surface ECG using vector velocity imaging in patients with hypertrophic cardiomyopathy

Article

Full-text available

Sep 2020
ANN NONINVAS ELECTRO

Objectives: Heterogeneity of structural and electrophysiologic properties of atrial myocardium is common characteristic in hypertrophic cardiomyopathy (HCM). We assessed the dispersion of atrial refractoriness on surface ECG using P-wave dispersion (PWD) and its relation to atrial electromechanical functions using vector velocity imaging (VVI) in HCM population. Methods: Seventy-nine HCM patients (mean age: 43.7 ± 13 years, 67% male) were compared with 25 healthy individuals as control. P-wave durations, Pmax and Pmin , P-wave dispersion (PWD), and P terminal force (PTF) were measured from 12-lead ECG. LA segmental delay (TTP-d) and dispersion (TTP-SD) of electromechanical activation were derived from atrial strain rate curves. Results: HCM patients had longer PR interval, PW duration, higher PWD, PTF, QTc compared to control (p < .001). HCM patients were classified according to presence of PWD into two groups, group I with PWD > 46 ms (n = 25) and group II PWD ≤ 46 ms (n = 54). Group I showed higher prevalence of female gender, higher PTF, QTc interval, left ventricular outflow tract (LVOT) obstruction, p < .01, LVOT gradient (p < .001), LV mass index (p < .01), E/E' (p < .01), and severe mitral regurgitation (p < .001). Moreover, PWD was associated with increased atrial electromechanical delay (TTP-d) and LA mechanical dyssynchrony (TTP-SD), p < .001. LA segmental delay and dispersion of electromechanical activation were distinctly higher among HCM patient. Conclusion: PWD is simple ECG criterion, and it is associated with more severe HCM phenotype and LA electromechanical delay while PTF is linked only to atrial remodeling.

Mid-ventricular Takotsubo syndrome 'lockdown'-related during coronavirus disease 2019 outbreak: a case report

Article

Sep 2020
J CARDIOVASC MED

Myocardial infarction with nonobstructed coronary arteries following accidental nitrogen inhalation: diagnosis by cardiac magnetic resonance and coronary computed tomography

Article

Jan 2019

Acute heart failure in Yemen

Article

Dec 2018

P-wave dispersion: What we know till now?

Article

Full-text available

Mar 2016

P-wave dispersion is defined as the difference between the maximum and the minimum P-wave duration recorded from multiple different-surface ECG leads. It has been known that increased P-wave duration and P-wave dispersion reflect prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses, which are well-known electrophysiologic characteristics in patients with atrial arrhythmias and especially paroxysmal atrial fibrillation. Extensive clinical evaluation of P-wave dispersion has been performed in the assessment of the risk for atrial fibrillation in patients without apparent heart disease, in hypertensives, in patients with coronary artery disease, in patients undergoing coronary artery bypass surgery, in patients with congenital heart diseases, as well as in other groups of patients suffering from various cardiac or non-cardiac diseases. In this paper, we aimed to summarize the measurement methods, current use in different clinical situations, strengths and limitations of the of P-wave dispersion.

P-Wave Indices: Derivation of Reference Values from the Framingham Heart Study

Article

Oct 2010
ANN NONINVAS ELECTRO

P-wave indices, an electrocardiographic phenotype reflecting atrial electrophysiology and morphology, may be altered in multiple disease states or by cardiovascular risk factors. Reference values for P-wave indices, providing cut points for their classification and interpretation, have not yet been established and are essential toward facilitating clinical application and comparison between studies. We randomly selected 20 men and 20 women from 10-year age intervals between <25 years to 76-85 years from the Framingham Heart Study Original and Offspring Cohorts, excluding subjects with prevalent cardiovascular disease, hypertension, diabetes or obesity. The total included 295 subjects; eligibility in women >75 years was limited by exclusion criteria. We used a digital measurement technique with demonstrated intrarater reproducibility to determine P-wave indices. P-wave indices examined included the maximum, mean, lead II and PR durations, dispersion, and the standard deviation of duration. All P-wave indices were significantly (P < 0.0001) correlated with advancing age. Means of all P-wave indices were lower in women as compared to men. PR-interval duration was strongly correlated with maximum, mean, and lead II mean P-wave durations. In multivariable models adjusting for significant anthropometric and clinical associations risk factors, significant differences persisted by age and sex in P-wave indices. In our healthy sample without cardiovascular disease, hypertension, diabetes, or obesity, men and older subjects had longer mean P-wave indices. Our description of P-wave indices establishes reference values for future comparative studies and facilitates the classification of P-wave indices.

Effect of body mass index (BMI) on electrocardiographic P-wave dispersion among healthy adults

Article

Sep 2023

Background: According to the results of an electrocardiogram (ECG), a higher body mass index (BMI) indicates body fat and is linked to a higher risk of cardiovascular illnesses. A noninvasive ECG signal called P-wave dispersion (Pd) can predict the likelihood of an atrial arrhythmia and reflects atrial remodeling. Pd is calculated by computing the difference between the maximum and minimum P-wave lengths captured from the 12 ECG lead recordings. To assess the early-stage risk of acquiring cardiovascular illnesses, we investigated the effect of BMI on P-wave dispersion in healthy, overweight, and obese adults. Materials and Methods: Depending on their body mass index (BMI), we divided 200 participants into three groups (normal weight, overweight, and obese) during a comparative cross-sectional study. We measured 12-lead surface ECG and P-wave dispersion in study participants. Results: Mean P-wave lengths were 33.23(± 6.08), 33.15(± 5.16), and 46.15 (± 5.37), respectively, for people who were normal weight, overweight, and obese. Between the normal-weight and obese groups and the overweight and obese groups, there was a statistically significant difference (p < 0.001), according to Tukey's post-hoc analysis. However, the normal-weight and overweight groups showed no statistically significant difference (P = 0.997). Pearson's correlation analysis shows that P-wave dispersion and BMI showed a significant positive connection (r = 0.632). Conclusion: A higher BMI is linked to a longer P-wave duration and dispersion, even in healthy adults. The likelihood of left atrial hypertrophy and atrial arrhythmia increases with a prolonged P-wave duration. This study emphasizes the importance of raising awareness about the need to adopt healthy lifestyles to avoid the harmful effects of obesity on the heart.

Research progress on predicting atrial fibrillation recurrence after radiofrequency ablation based on electrocardiogram-related parameters

Preprint

May 2023

Atrial fibrillation (AF) is the most common arrhythmia. It is associated with increased stroke risks, thromboembolism, and other complications, which are great life and economic burdens for patients. In recent years, with the maturity of percutaneous catheter radiofrequency ablation (RFA) technology, it has become a first-line therapy for AF. However, some patients still experience AF recurrence (AFR) after RFA, which can cause serious consequences. Therefore, it is crucial to identify appropriate parameters that can predict the prognosis. Here, we reviewed possible predicting indicators for AFR, focusing on all the electrocardiogram indicators, such as P wave duration, PR interval and so on. It may provide valuable information for guiding clinical works.

The Effect of Severe Pain on Transmyocardial Repolarization Parameters in Renal Colic Patients

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Sep 2022

Signs of left atrial disease and 10-year risk of atrial fibrillation

Article

Full-text available

Apr 2022
PLOS ONE

Background The contribution of left atrial disease and excessive supraventricular ectopic activity (ESVEA) to the risk for incident atrial fibrillation (AF) is incompletely understood. Objective To analyse the ten-year risk to develop AF in patients with cardiovascular risk factors and to define the impact of parameters of left atrial disease and ESVEA on AF risk. Methods 148 patients from the Diast-CHF trial with at least one cardiovascular risk factor and free of AF at baseline were followed for 10 years. Left atrial disease was defined as left atrial volume index (LAVI) >35 ml/m ² , P-terminal force in lead V 1 (PTFV 1 ) >4000 ms*μV or elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) >250 pg/ml. We analyzed the association of these parameters and ESVEA (either >720 premature atrial contractions (PAC) or one atrial run >20 beats per day) on AF-free survival. Results After ten years, AF was newly detected in twelve patients (13.4%) with signs of left atrial disease and two patients (3.4%) without signs of left atrial disease (p = 0.04). LAVI (p = 0.005), ESVEA (p = 0.016) and NT-proBNP (p = 0.010) were significantly associated with AF-free survival in univariate analysis. A combined Cox model of left atrial disease parameters showed associations for NT-proBNP (HR 3.56; 95%CI 1.33–5.31; p = 0.04) and PAC (HR 2.66; 95%CI 1.25–10.15; p = 0.01) but not for LAVI or PTFV 1 with AF-free survival. Conclusion The risk for AF is higher in patients with cardiovascular risk factors and signs of left atrial disease. NT-proBNP and premature atrial contractions independently predict AF-free survival. The role of excessive supraventricular ectopic activity for the assessment of AF risk may be underestimated and requires further study.

An Exploratory Study on Vectorcardiographic Identification of the Site of Origin of Focally Induced Premature Depolarizations in Horses, Part I: The Atria

Article

Full-text available

Feb 2022

In human cardiology, the anatomical origin of atrial premature depolarizations (APDs) is derived from P wave characteristics on a 12-lead electrocardiogram (ECG) and from vectorcardiography (VCG). The objective of this study is to differentiate between anatomical locations of APDs and to differentiate APDs from sinus rhythm (SR) based upon VCG characteristics in seven horses without cardiovascular disease. A 12-lead ECG was recorded under general anaesthesia while endomyocardial atrial pacing was performed (800–1000 ms cycle length) at the left atrial free wall and septum, right atrial free wall, intervenous tubercle, as well as at the junction with the cranial and caudal vena cava. Catheter positioning was guided by 3D electro-anatomical mapping and transthoracic ultrasound. The VCG was calculated from the 12-lead ECG using custom-made algorithms and was used to determine the mean electrical axis of the first and second half of the P wave. An ANOVA for spherical data was used to test if the maximal directions between each paced location and the maximal directions between every paced location and SR were significantly (p < 0.05) different. Atrial pacing data were not available from the LA septum in three horses, the intervenous tubercle in two horses, and from the LA free wall in one horse. The directions of the maximal electrical axes showed significant differences between all paced locations and between the paced locations and SR. The current results suggest that VCG is useful for identifying the anatomical origin of an atrial ectopy.

The Association Between Standard Electrocardiography and Cerebral Small Vessel Disease in a Memory Clinic Study

Article

Full-text available

Feb 2022
J ALZHEIMERS DIS

Background: P-wave terminal force in lead V1 (PTFV1) on electrocardiography has been associated with atrial fibrillation and ischemic stroke. Objective: To investigate whether PTFV1 is associated with cerebral small vessel disease (CSVD) markers and etiological subtypes of cognitive impairment and dementia. Methods: Participants were recruited from ongoing memory clinic study between August 2010 to January 2019. All participants underwent physical and medical evaluation along with an electrocardiography and 3 T brain magnetic resonance imaging. Participants were classified as no cognitive impairment, cognitive impairment no dementia, vascular cognitive impairment no dementia, and dementia subtypes (Alzheimer's disease and vascular dementia). Elevated PTFV1 was defined as > 4,000μV×ms and measured manually on ECG. Results: Of 408 participants, 78 (19.1%) had elevated PTFV1 (37 women [47%]; mean [SD] age, 73.8 [7.2] years). The participants with elevated PTFV1 had higher burden of lacunes, cerebral microbleeds (CMB), and cortical microinfarcts. As for the CMB location, persons with strictly deep CMB and mixed CMB had significantly higher PTFV1 than those with no CMB (p = 0.005, p = 0.007). Regardless of adjustment for cardiovascular risk factors and/or heart diseases, elevated PTFV1 was significantly associated with presence of CMB (odds ratio, 2.26; 95% CI,1.33-3.91). Conclusion: Elevated PTFV1 was associated with CSVD, especially deep CMB. PTFV1 in vascular dementia was also higher compared to Alzheimer's disease. Thus, PTFV1 might be a potential surrogate marker of brain-heart connection and vascular brain damage.

The Relationship Between Intrahospital Mortality and P-Wave Dispersion in COVID-19 Patients

Article

Full-text available

Nov 2021

Aim:P-wave dispersion (PWD) is a noninvasive electrocardiographic (ECG) marker of atrial remodeling. Inflammations are likely to cause atrial remodeling. This study aims to determine the relationship between PWD and intrahospital mortality in Coronavirus disease-2019 (COVID-19) patients.Methods:One hundred eighty-nine patients who tested positive for polymerase chain reaction for a diagnosis of COVID-19 between March 2020 and January 2021 were included in the cross-sectional study. PWD was calculated from the pre-treatment ECG of all patients at the time of hospitalization.Results:Mean PWD values were numerically and statistically significant in the group who died in hospital compared to the group discharged after recovery (46.37±19.00 ms vs. 31.86±11.08 ms, p

P wave dispersion over two decades after its discovery. What the cardiologist should know

Article

Sep 2020

For years, there has been an increase in cases of atrial fibrillation, reaching alarming levels. This is why intense work is done to find predictors of this arrhythmia. The electrocardiogram has shown to be useful for this purpose, and multiple indices derived from the P wave have been developed. Among the most notable is the P wave dispersion (PWD). It has been verified that PWD can predict the occurrence of paroxysmal atrial fibrillation in the absence of diseases as well as in the context of multiple cardiovascular pathologies or other systems. PWD is considered by most researchers to be the result of inhomogeneous conduction of the atrial electrical impulse, but a vector explanation may play a role in its genesis. The large body of evidence surrounding PWD supports its use in clinical practice.

Electrocardiographic Left Atrial Abnormality and B-Type Natriuretic Peptide in a General Japanese Population: NIPPON DATA2010

Article

Full-text available

Mar 2020

Aims: P-wave terminal force in lead V1 (PTFV1) is an electrocardiogram marker of increased left atrial pressure and may be a noninvasive and early detectable marker for future cardiovascular events in the general population compared to serum B-type natriuretic peptide (BNP) concentration. The clinical significance of PTFV1 in the contemporary general population is an area of unmet need. We aimed to demonstrate the correlation between PTFV1 and BNP concentrations in a contemporary representative Japanese population. Methods: Among 2,898 adult men and women from 300 randomly selected districts throughout Japan (NIPPON DATA2010), we analyzed 2,556 participants without cardiovascular disease (stroke, myocardial infarction, and atrial fibrillation). Elevated BNP was defined as a value of ≥ 20 pg/mL based on the definition from the Japanese Circulation Society guidelines. Results: In total, 125 (4.9%) participants had PTFV1. Participants with PTFV1 were older with a higher prevalence of hypertension, major electrocardiographic findings, and elevated BNP concentrations (13.5 [6.9, 22.8] versus 7.8 [4.4, 14.5] pg/mL; P＜0.001). After adjustment for confounders, PTFV1 was correlated with elevated BNP (odds ratio, 1.66; 95% confidence interval, 1.05–2.62; P=0.030). This correlation was consistent among various subgroups and was particularly evident in those aged ＜65 years or those without a history of hypertension. Conclusions: In the contemporary general population cohort, PTFV1 was independently related to high BNP concentration. PTFV1 may be an alternative marker to BNP in identifying individuals at a higher risk of future cardiovascular events in the East Asian population.

The Effect of Dapagliflozin Treatment on Epicardial Adipose Tissue Volume and P-Wave Indices: An Ad-hoc Analysis of The Previous Randomized Clinical Trial

Article

Full-text available

Feb 2020

Aim: Epicardial adipose tissue (EAT) may be associated with arrhythmogenesis. P-wave indices such as P-wave dispersion and P-wave variation indicated a slowed conduction velocity within the atria. This study investigated the effect of dapagliflozin on EAT volume and P-wave indices. Methods: In the present ad hoc analysis, 35 patients with type 2 diabetes mellitus and coronary artery disease were classified into dapagliflozin group (n=18) and conventional treatment group (n=17). At baseline, EAT volume, HbA1c and plasma level of tumor necrotic factor-α (TNF-α) levels, echocardiography, and 12-lead electrocardiogram (ECG) were performed. EAT volume was measured using computed tomography. Using 12-lead ECG, P-wave indices were measured. Results: At baseline, EAT volumes in the dapagliflozin and conventional treatment groups were 113±20 and 110±27 cm³, respectively. Not only HbA1c and plasma level of TNF-α but also echocardiography findings including left atrial dimension and P-wave indices were comparable between the two groups. After 6 months, plasma level of TNF-α as well as EAT volume significantly decreased in the dapagliflozin group only. P-wave dispersion and P-wave variation significantly decreased in the dapagliflozin group only (-9.2±8.7 vs. 5.9±19.9 ms, p=0.01; -3.5±3.5 vs. 1.7±5.9 ms, p=0.01). The change in P-wave dispersion correlated with changes in EAT volume and plasma level of TNF-α. In multivariate analysis, the change in EAT volume was an independent determinant of the change in P-wave dispersion. Conclusion: Dapagliflozin reduced plasma level of TNF-α, EAT volume, and P-wave indices, such as P-wave dispersion. The changes in P-wave indices were especially associated with changes in EAT volume. The number and date of registration: UMIN000035660, 24/Jan/2019

Elongation of the high right atrium to coronary sinus conduction time predicts the recurrence of atrial fibrillation after radiofrequency catheter ablation

Article

Full-text available

Nov 2019
INT J CARDIOL

Background: The impact of intra-atrial conduction delay on the recurrence of atrial tachyarrhythmia after radio frequency catheter ablation (RFCA) has not been fully elucidated. Methods: We retrospectively analyzed 155 AF patients who were sinus rhythm at the start of RFCA. The conduction time from the onset of the earliest atrial electrogram at the high right atrium (HRA) to the end of the latest electrogram at the coronary sinus (CS) during sinus rhythm was defined as HRA-CS conduction time. Pulmonary vein isolation (PVI) was performed followed by linear roof lesion and complex fractionated atrial electrogram (CFAE) ablation until AF termination. We evaluated atrial tachyarrhythmia recurrence 12 months after RFCA. Results: The follow-up data were available for 148 patients. The recurrence of atrial tachyarrhythmia was noted in 28 (18.9%) patients. Atrial tachyarrhythmia recurrence patients had longer HRA-CS conduction times (151.3 ± 22.1 ms vs 160.1 ± 32.6 ms, p = .017). The patients were divided into the long or short HRA-CS conduction time group. The Kaplan-Meier analysis revealed that the long HRA-CS conduction time group held a higher risk of atrial tachyarrhythmia recurrence (log-rank test, p = .019). The multivariable Cox hazard analysis revealed that a long HRA-CS conduction time was a significant risk factor for the recurrence of atrial tachyarrhythmia, despite a long AF duration, persistent AF, and larger left atrial diameter (LAD) were not statistically significant. Conclusions: The HRA-CS conduction time was the primary influencing factor that predicted the recurrence of atrial tachyarrhythmia after catheter ablation.

Impact of Transcatheter Device Closure of Atrial Septal Defect on Atrial Arrhythmias Propensity in Young Adults

Article

Full-text available

Jan 2020
PEDIATR CARDIOL

Atrial septal defect (ASD) is a condition that requires early intervention because of the consequences over the right-side heart. Chronic atrial stretching promotes atrial conduction delay and the imbalance of the conduction homogeneity, which lead to the propensity to atrial arrhythmias (AA). We aim to evaluate the impact of transcatheter closure of ASD on atrial vulnerability markers leading to late AA in young adults. We conducted a prospective, longitudinal study in one hundred patients (mean age 25.2 ± 5.4 years) who underwent transcatheter closure of ASD at Cardiocentro Pediátrico William Soler. P-wave maximum (Pmax) and P-wave dispersion (Pd) were analyzed from 12-lead electrocardiogram. Left-side and right-side intraatrial and interatrial electromechanical delay (EMD) were measured with tissue Doppler imaging. Both electrocardiographic and echocardiographic analyses were performed during the study period. Compared to baseline, there was a significant reduction in P max (p ≤ 0.001) and Pd (p ≤ 0.001) after 3 months of procedure. All atrial electromechanical coupling parameters significantly reduced at 6 months of ASD closure and tend to remain at lower values till the last evaluation. Over 9.2 ± 1.6 years of follow-up, 15 subjects (15%) developed AA, of which intraatrial reentrant tachycardia (66.6%) became the main rhythm disturbance. Intra-right atrial EMD ≥ 16 ms (HR 4.08, 95% CI 1.15–14.56; p = 0.03) and Pd 45 ms (HR 1.66, 95% CI 1.06–2.59; p = 0.02) were identified as predictors of late AA. Transcatheter device closure of ASD in young adults promotes a significant reduction of electrocardiographic and echocardiographic markers of AA vulnerability, which persist during the long-term follow-up. Nevertheless, Pd and interatrial EMD were identified as independent risk factors of AA.

Electrocardiographic left atrial abnormality and silent vascular brain injury: The Northern Manhattan Study

Article

Full-text available

Oct 2018
PLOS ONE

Hypothesis: We hypothesized that P wave terminal Force in the V1 lead (PTFV1) would be associated with leukoaraiosis and subclinical infarcts, especially cortical infarcts, in a population-based, multi-ethnic cohort. Methods: PTFV1 was collected manually from baseline electrocardiograms of clinically stroke-free Northern Manhattan Study participants. Investigators read brain MRIs for superficial infarcts, deep infarcts, and white matter hyperintensity volume (WMHV). WMHV was adjusted for head size and log transformed, achieving a normal distribution. Logistic regression models investigated the association of PTFV1 with cortical and with all subclinical infarcts. Linear regression models examined logWMHV. Models were adjusted for demographics and risk factors. Results: Among 1174 participants with PTFV1 measurements, the mean age at MRI was 70 ± 9 years. Participants were 14.4% white, 17.6% black, and 65.8% Hispanic. Mean PTFV1 was 3587.35 ± 2315.62 μV-ms. Of the 170 subclinical infarcts, 40 were cortical. PTFV1 ≥ 5000 μV-ms was associated with WMHV in a fully adjusted model (mean difference in logWMHV 0.15, 95% confidence interval 0.01-0.28). PTFV1 exhibited a trend toward an association with cortical infarcts (unadjusted OR per SD change logPTFV1 1.30, 95% CI 0.94-1.81), but not with all subclinical infarcts. Conclusion: Electrocardiographic evidence of left atrial abnormality was associated with leukoaraiosis.

The relationship between echocardiographic epicardial adipose tissue, P-wave dispersion, and corrected QT interval

Article

Full-text available

Sep 2018

Alaa Quisi

Objective: Epicardial adipose tissue (EAT) secretes various pro-inflammatory and atherogenic substances that have several effects on the heart. The goal of this study was to evaluate the association between EAT thickness and both P-wave dispersion (Pd) and corrected QT interval (QTc), as simple, non-invasive indicators of arrhythmia on a surface electrocardiogram. Methods: This retrospective observational study included 216 patients who had normal coronary arteries observed on coronary angiography. Each patient underwent 12-derivation electrocardiography to measure Pd and QTc, and transthoracic echocardiography to measure EAT thickness. The patients were divided into 2 groups according to the median EAT value (EAT low group: <5.35 mm; EAT high group: ≥5.35 mm). Results: P-wave dispersion (p=0.001) was significantly greater in the EAT high group compared with the EAT low group. However, the QTc (p=0.004) was significantly greater in the latter group. The median left ventricular end-diastolic diameter (p=0.033), mean left ventricular end-systolic diameter (p=0.039), and mean left atrial diameter (p=0.012) were significantly greater in the EAT high group. Multiple logistic regression analysis using the backward elimination method revealed that the leukocyte count (Odds ratio [OR]: 1.000; 95% confidence interval [CI]: 1.000–1.000; p=0.001), Pd (OR: 1.1026; 95% CI: 1.010–1.043; p=0.002), QTc interval (OR: 0.988; 95% CI: 0.979–0.997; p=0.009), and left ventricular ejection fraction (OR: 0.922; 95% CI: 0.859–0.989; p=0.023) were independently associated with greater EAT thickness. Conclusion: Echocardiographic end-diastolic EAT thickness on the free wall of the right ventricle was associated with Pd and QTc in patients with normal coronary arteries.

Association between serum cotinine levels and electrocardiographic left atrial abnormality

Article

Full-text available

Aug 2018
ANN NONINVAS ELECTRO

Background Although the harmful effect of tobacco exposure on cardiovascular disease (CVD) and its risk factors are well established, the constituents of cigarette‐smoke and the pathophysiological mechanism involved are unknown. Recently, deep terminal negativity of P wave in V1 (DTNPV1) has emerged as a marker of left atrial abnormality that predicts atrial fibrillation, stroke, and death due to all‐cause or CVD. Therefore, we examined the association between serum cotinine levels with abnormal DTNPV1 using the Third National Health and Nutrition Examination Survey. Methods This analysis included 4,507 participants (mean age 58 ± 13 years, 53% women, 49% non‐Hispanic white) of NHANES III, without history of CVD or major electrocardiographic abnormalities and not on heart rate modifying medications. Multivariable logistic regression analysis was used to examine the association between serum cotinine and abnormal DTNPV1—defined from automatically processed electrocardiograms as values of the amplitude of the terminal negative phase of P wave in lead V1 exceeding 100 μV. Results Abnormal DTNPV1 was detected in 2.3% (n = 105) of the participants. In a model adjusted for demographics and CVD risk factors, each 10 ng/ml serum cotinine was associated with 2% increased odds of abnormal DTNPV1 (odds ratio 1.02, 95% confidence interval 1.01–1.03, p‐value < 0.001). This association was consistent in subgroups stratified by age, sex, race, smoking status, hypertension, diabetes, dyslipidemia, and chronic obstructive pulmonary disease. Conclusion Elevated serum cotinine levels are associated with an abnormal DTNPV1. This suggests that nicotine exposure can lead to left atrial abnormalities, a possible mechanism for increased risk of CVD.

The role of P-wave dispersion in dystrophic and thalassemic cardiomyopathy

Article

Full-text available

Jul 2017

Recent Advances in the Noninvasive Study of Atrial Conduction Defects Preceding Atrial Fibrillation

Chapter

Full-text available

Aug 2015

The P-wave represents the electrical activity in the electrocardiogram (ECG) associ‐ ated with the heart's atrial contraction. This wave has merited significant research efforts in recent years with the aim to characterize atrial depolarization from the ECG. Indeed, the alterations of the P-wave main time, frequency, and wavelet features have been widely studied to predict the onset of atrial fibrillation (AF), both spontaneously and after a specific treatment, such as pharmacological or electrical cardioversion, catheter ablation, as well as cardiac surgery. To this respect, the P-wave prolongation is today a clinically accepted marker of high risk of suffering AF. However, given the relatively low P-wave amplitude in the ECG, its analysis has been most widely carried out from signal-averaged ECG signals. Unfortunately, these kind of recordings are uncommon in routine clinical practice and, moreover, they obstruct the possibility of studying the information carried by each single P-wave as well as its variability over time. These limitations have motivated the recent development of the beat-to-beat P-wave analysis, which has proven to be very useful in revealing interesting information about the altered atrial conduction preceding the onset of AF. Within this context, the main goal of this chapter is to review the most recent advances reached by this kind of analysis in the noninvasive assessment of atrial conduction alterations. Thus, the chapter will introduce and discuss the existing methods of the beat-to-beat P-wave analysis and their application to predict the onset of AF as well as its advantages and disadvantages compared with the signal-averaged P-wave analysis.

Electrocardiographic Left Atrial Abnormality and Risk of Stroke: Northern Manhattan Study

Article

Full-text available

Sep 2015
STROKE

Background and purpose: Electrocardiographic left atrial abnormality has been associated with stroke independently of atrial fibrillation (AF), suggesting that atrial thromboembolism may occur in the absence of AF. If true, we would expect an association with cryptogenic or cardioembolic stroke rather than noncardioembolic stroke. Methods: We conducted a case-cohort analysis in the Northern Manhattan Study, a prospective cohort study of stroke risk factors. P-wave terminal force in lead V1 was manually measured from baseline ECGs of participants in sinus rhythm who subsequently had ischemic stroke (n=241) and a randomly selected subcohort without stroke (n=798). Weighted Cox proportional hazard models were used to examine the association between P-wave terminal force in lead V1 and stroke etiologic subtypes while adjusting for baseline demographic characteristics, history of AF, heart failure, diabetes mellitus, hypertension, tobacco use, and lipid levels. Results: Mean P-wave terminal force in lead V1 was 4452 (±3368) μV*ms among stroke cases and 3934 (±2541) μV*ms in the subcohort. P-wave terminal force in lead V1 was associated with ischemic stroke (adjusted hazard ratio per SD, 1.20; 95% confidence interval, 1.03-1.39) and the composite of cryptogenic or cardioembolic stroke (adjusted hazard ratio per SD, 1.31; 95% confidence interval, 1.08-1.58). There was no definite association with noncardioembolic stroke subtypes (adjusted hazard ratio per SD, 1.14; 95% confidence interval, 0.92-1.40). Results were similar after excluding participants with a history of AF at baseline or new AF during follow-up. Conclusions: ECG-defined left atrial abnormality was associated with incident cryptogenic or cardioembolic stroke independently of the presence of AF, suggesting atrial thromboembolism may occur without recognized AF.

Electrocardiographic Left Atrial Abnormality and Stroke Subtype in ARIC

Article

Jul 2015
ANN NEUROL

To assess the relationship between abnormally increased P-wave terminal force in lead V1 (PTFV1 ), an electrocardiographic (ECG) marker of left atrial abnormality, and incident ischemic stroke subtypes. We hypothesized that associations would be stronger with non-lacunar stroke, since we expected left atrial abnormality to reflect the risk of thromboembolism rather than in-situ cerebral small-vessel occlusion. Our cohort comprised 14,542 participants 45-64 years of age prospectively enrolled in the Atherosclerosis Risk in Communities (ARIC) study and free of clinically apparent atrial fibrillation (AF) at baseline. Left atrial abnormality was defined as PTFV1 >4,000 μV*ms. Outcomes were adjudicated ischemic stroke, non-lacunar (including cardioembolic) ischemic stroke, and lacunar stroke. During a median follow-up period of 22 years (interquartile range, 19-23 years), 904 participants (6.2%) experienced a definite or probable ischemic stroke. A higher incidence of stroke occurred in those with baseline left atrial abnormality (incidence rate per 1,000 person-years, 6.3; 95% CI, 5.4-7.4) than in those without (incidence rate per 1,000 person-years, 2.9; 95% CI, 2.7-3.1; P < 0.001). In Cox regression models adjusted for potential confounders and incident AF, left atrial abnormality was associated with incident ischemic stroke (HR, 1.33; 95% CI, 1.11-1.59). This association was limited to non-lacunar stroke (HR, 1.49; 95% CI, 1.07-2.07) as opposed to lacunar stroke (HR, 0.89; 95% CI, 0.57-1.40). This article is protected by copyright. All rights reserved. © 2015 American Neurological Association.

Prediction of Paroxysmal Atrial Fibrillation through Spectral and Statistical Techniques

Article

Jan 2015

P-wave dispersion and its relationship with the severity of the disease in patients with stable coronary artery disease

Article

Full-text available

Dec 2014

Fatih Akin

OBJECTIVE P- wave dispersion (PD) is an indicator of inhomogeneous and discontinuous propagation of sinus impulses. In the present study we aimed to investigate the PD and its association with the severity of the disease. in patients with stable coronary artery disease. METHODS We prospectively analyzed 60 subjects with coronary artery disease (CAD) and 25 subjects with nor-mal coronary angiograms (control group). The maximum and minimum P-wave duration and PD were measured from the 12-lead surface electrocardiograms. The CAD severity was assessed by the severity score (Gensini score) and the number of vessels involved (vessel score). RESULTS P max was longer in CAD group compared with the control group (p<0.001). PD was greater in the CAD group, compared with the control group (p<0.001). However, P min did not differ between the two groups. In bi-variate correlation, increased PD was correlated with presence of diabetes mellitus (r=0.316, p=0.014), smoking (r=0.348, p=0.006), left ventricular ejection fraction (r=-0.372, p=0.003), vessel score (r=0.848, p=0.001), and Gensini score (r=0.825, p=0.001). Multiple linear regression analysis showed that PD was independently associ¬ated with vessel score ((3=0.139, p=0.002) and Gensini score ((3=0.132, p=0.007). CONCLUSION PD was greater in patients with CAD than in controls and it was associated with CAD severity.

Assessment of Reproducibility – Automated and Digital Caliper ECG Measurement in the Framingham Heart Study

Article

May 2014

Short-Term Repeatability of Electrocardiographic P Wave Indices and PR Interval

Article

Nov 2013

P wave indices and PR interval from 12-lead electrocardiograms (ECGs) are predictors of cardiovascular morbidity and mortality, but their repeatability has not been examined. Determine the short-term repeatability of P wave indices (P axis, maximum P area and duration, P dispersion and P terminal force in V1) and PR interval. Participants (n=63) underwent two standard ECGs at each of two visits, two weeks apart. We calculated the intra-class correlation coefficient (ICC), weighted kappa, and minimal detectable change and difference. ICCs were 0.93 for PR interval, 0.78 for P axis, 0.77 for maximum P area, and 0.58 for maximum P duration. Within- and between-visit Kappa were 0.30 and 0.11 for P dispersion, and 0.68 and 0.46 for P terminal force. Repeatability of PR duration was excellent, that of P wave axis and maximum area was fair, and maximum P wave duration and terminal force was poor. Repeatability of P wave dispersion was fair within visit, yet poor between visits. These results illustrate potential biases when measurement error of some P wave indices is ignored in clinical and epidemiologic studies.

Study on the P-wave feature time course as early predictors of paroxysmal atrial fibrillation

Article

Full-text available

Nov 2012
PHYSIOL MEAS

Atrial fibrillation (AF) is the most common cardiac arrhythmia in clinical practice, increasing the risk of stroke and all-cause mortality. Its mechanisms are poorly understood, thus leading to different theories and controversial interpretation of its behavior. In this respect, it is unknown why AF is self-terminating in certain individuals, which is called paroxysmal AF (PAF), and not in others. Within the context of biomedical signal analysis, predicting the onset of PAF with a reasonable advance has been a clinical challenge in recent years. By predicting arrhythmia onset, the loss of normal sinus rhythm could be addressed by means of preventive treatments, thus minimizing risks for the patients and improving their quality of life. Traditionally, the study of PAF onset has been undertaken through a variety of features characterizing P-wave spatial diversity from the standard 12-lead electrocardiogram (ECG) or from signal-averaged ECGs. However, the variability of features from the P-wave time course before PAF onset has not been exploited yet. This work introduces a new alternative to assess time diversity of the P-wave features from single-lead ECG recordings. Furthermore, the method is able to assess the risk of arrhythmia 1 h before its onset, which is a relevant advance in order to provide clinically useful PAF risk predictors. Results were in agreement with the electrophysiological changes taking place in the atria. Hence, P-wave features presented an increasing variability as PAF onset approximates, thus suggesting intermittently disturbed conduction in the atrial tissue. In addition, high PAF risk prediction accuracy, greater than 90%, has been reached in the two considered scenarios, i.e. discrimination between healthy individuals and PAF patients and between patients far from PAF and close to PAF onset. Nonetheless, more long-term studies have to be analyzed and validated in future works.

Susceptibility to Paroxysmal Atrial Fibrillation: A Study using Sinus Rhythm P Wave Parameters

Conference Paper

Full-text available

Oct 2010

Early recognition of patients at high risk for atrial fibrillation may help to minimize potential health risks. The detection of susceptibility to develop atrial fibrillation is thus a real clinical challenge. Whereas many studies have used the signal-averaged P wave, the aim of this work is to determine whether electrocardiographic parameters resulting from the analysis of the P wave in ECG recorded during sinus rhythm could be markers for paroxysmal atrial fibrillation susceptibility. Our idea was to compare the ECG in sinus rhythm from two populations: healthy people and patients subject to paroxysmal atrial fibrillation. In addition to standard P wave parameters (P width, P-R interval,...), the Euclidean distance between beat-to-beat P waves, which has been rarely addressed in this context, was studied on lead V1. Significant differences between the healthy and the paroxysmal atrial fibrillation groups were obtained for various parameters. Moreover, a classification of the two groups based on the joint analysis of P width and P-R interval was suggested. This proposed classification could lead to an effective identification of patients at risk to develop atrial fibrillation.

P-wave Dispersion for Predicting Paroxysmal Atrial Fibrillation in Acute Ischemic Stroke

Article

Full-text available

Jan 2012
Int J Med Sci

Detection of paroxysmal atrial fibrillation (PAF) in acute ischemic stroke patients poses diagnostic challenge. The aim of this study was to predict the presence of PAF by means of 12-lead ECG in patients with acute ischemic stroke. Our hypothesis was that P-wave dispersion (P(d)) might be a useful marker in predicting PAF in patients with acute ischemic stroke. 12-lead resting ECGs, 24-hour Holter recordings and echocardiograms of 400 patients were analyzed retrospectively. PAF was detected in 40 patients on 24-hour Holter monitoring. Forty out of 360 age and gender matched patients without PAF were randomly chosen and assigned as the control group. Demographics, P-wave characteristics and echocardiographic findings of the patients with and without PAF were compared. Maximum P-wave duration (p=0.002), P(d) (p<0.001) and left atrium diameter (p=0.04) were significantly higher in patients with PAF when compared to patients without PAF. However, in binary logistic regression analysis P(d) was the only independent predictor of PAF. The cut-off value of P(d) for the detection of PAF was 57.5 milliseconds (msc). Area under the curve was 0.80 (p<0.001). On a single 12-lead ECG, a value higher than 57.5 msc predicted the presence of PAF with a sensitivity of 80% and a specificity of 73%. P(d) on a single 12-lead ECG obtained within 24 hours of an acute ischemic stroke might help to predict PAF and reduce the risk of recurrent strokes.

P Wave Duration and Risk of Longitudinal Atrial Fibrillation in Persons >= 60 Years Old (from the Framingham Heart Study)

Article

Mar 2011

Long-term risk prediction is a priority for the prevention of atrial fibrillation (AF). P wave indices are electrocardiographic measurements describing atrial conduction. The role of P wave indices in the prospective determination of AF and mortality risk has had limited assessment. We quantified by digital caliper the P wave indices of maximum duration and dispersion in 1,550 Framingham Heart Study participants ≥ 60 years old (58% women) from single-channel electrocardiograms recorded from 1968 through 1971. We examined the association of selected P wave indices and long-term outcomes using Cox proportional hazards regression incorporating age, gender, body mass index, systolic blood pressure, treatment for hypertension, significant murmur, heart failure, and PR interval. Over a median follow-up of 15.8 years (range 0 to 38.7), 359 participants developed AF and 1,525 died. Multivariable-adjusted hazard ratios (HRs) per SD increase in maximum P wave duration were 1.15 (95% confidence interval [CI] 0.90 to 1.47, p = 0.27) for AF and 1.02 (95% CI 0.96 to 1.08, p = 0.18) for mortality. The upper 5% of P wave maximum duration had a multivariable-adjusted HR of 2.51 (95% CI 1.13 to 5.57, p = 0.024) for AF and an HR of 1.11 (95% CI 0.87 to 1.40, p = 0.20) for mortality. We found no significant associations between P wave dispersion with incidence of AF or mortality. In conclusion, maximum P wave duration at the upper fifth percentile was associated with long-term AF risk in an elderly community-based cohort. P wave duration is an electrocardiographic endophenotype for AF.

Effect of chelation therapy on arrhythmogenic and basal ECG parameters of lead exposed workers

Article

Apr 2021

Lead exposure has etiological role on cardiovascular system diseases as hypertension, atherosclerosis, stroke, and arrhythmic events. In this study, we aimed to compare the basal and arrhythmogenic ECG parameters of lead exposed workers before and after chelation therapy and to evaluate the effect of acute change of blood lead levels on ECG. Fourty consecutive occupationally lead exposed workers were enrolled, demographic, blood, echocardiographic, and electrocardiographic data’s were analyzed before and after chelation therapy. Pmax, P min, P Wave Dispersion, and QT Dispersion values which are arrhythmia predictors were significantly lower after chelation therapy compared to values before chelation therapy. Lead exposed workers are under the risk of ventricular and atrial arrythmias and chelation treatment has a positive effect on these parameters.

Electrocardiographic left atrial abnormality in patients presenting with ischemic stroke

Article

Sep 2020
J Stroke Cerebrovasc Dis

Background P wave indices represent electrocardiographic marker of left atrial pathology. We hypothesized that P wave would be more abnormal in patients presenting with ischemic stroke than a comparable group without ischemic stroke. Methods We compared P wave terminal force in V1 (PTFV1) between patients admitted with ischemic stroke (case) and patients followed in cardiology clinic (control) at a single medical center. Using logistic regression models, we tested for an association between abnormal PTFV1 (> 4000 µV ms) and ischemic stroke. We also defined several optimal cut-off values of PTFV1 using a LOESS plot and estimated odds ratio of ischemic stroke when moving from one cut-point level to the next higher-level. Results A total of 297 patients (case 147, control 150) were included. PTFV1 was higher in patients with vs. those without ischemic stroke (median 4620 vs 3994 µV ms; p=0.006). PTFV1 was similar between cardioembolic/cryptogenic and other stroke subtypes. In multivariable analyses adjusting for sex, obesity, age, and hypertension, the association between abnormal PTFV1 and ischemic stroke ceased to be significant (OR 1.53 [0.95, 2.50], p=0.083). Increase to the next cutoff level of PTFV1 (900, 2000, 3000, 4000, 5000, and 6000 µV ms) was associated with 18% increase in odds of having ischemic stroke (vs. no ischemic stroke) (OR 1.18 [1.02, 1.36], p=0.026). Conclusion Patients presenting with acute ischemic stroke are more likely to have abnormal PTFV1. These findings from a real-world clinical setting support the results of cohort studies that left atrial pathology manifested as abnormal PTFV1 is associated with ischemic stroke.

Significance of left atrial overload by electrocardiogram in the assessment of left ventricular diastolic dysfunction

Article

Dec 2019

Background Although assessment of left ventricular (LV) diastolic function (DF) using echocardiography is important, it is not always feasible in the clinical practice. On the other hand, left atrial (LA) overload shown by electrocardiogram (ECG) indicates LA pressure rise and LA dilatation. The purpose of this study is to examine whether LA overload by ECG can be used as an aid for evaluation of LVDF. Methods There were 117 subjects who underwent echocardiography and ECG on the same day. The duration of P-wave (P-duration) in lead II, the amplitude and duration of P-wave negative phase in lead V1 were measured by ECG, and terminal force (PTFV1) was calculated. We analyzed the relationships between LVDF grades and LA overload signs. Results P-duration showed a good correlation with LA volume index (LAVi) (r = 0.673, P < 0.0001) and PTFV1 showed reasonable correlations with both LAVi and average E/e′ (both, r = 0.575, P < 0.0001). Both P-duration and PTFV1 showed significant differences among the LVDF classes (P < 0.0001). Among the ECG indices, P-duration \(\ge\) 110 ms was the most powerful to judge the presence of LV diastolic dysfunction with 86% of sensitivity and specificity. Conclusions P-duration ≥ 110 ms is useful to suggest the presence of LV diastolic dysfunction. Conventional ECG criteria (P-duration ≥ 120 ms and PTFV1 \(\ge\) 0.04 mm·s) are highly specific and suggest the presence of LV diastolic dysfunction with LA pressure rise. Echocardiography and ECG should be used in a complementary way when LVDF grades are indeterminate.

Change in P wave on electrocardiogram and its diagnostic value in children and adolescents with cardioinhibitory vasovagal syncope

Article

Nov 2019
Chin J Contemp Pediatr

Objective: To study the change in P wave on electrocardiogram and its diagnostic value in children and adolescents with cardioinhibitory vasovagal syncope (VVS-CI). Methods: A total of 43 children and adolescents who were diagnosed with VVS-CI were enrolled as the VVS-CI group, and 43 healthy children and adolescents were enrolled as the control group. P wave duration and P wave voltage were measured by 12-lead electrocardiography in a basal state, and the changes were analyzed. Results: Compared with the control group, the VVS-CI group had a significantly lower heart rate (P<0.05) and significantly longer P wave duration (Pwd), P wave maximum duration (Pmax), and corrected P wave maximum duration (Pcmax), as well as significantly higher P wave dispersion (Pd) and corrected P wave dispersion (Pcd) (P<0.05). Pwd, Pmax, Pd, Pcmax and Pcd had a certain diagnostic value in children and adolescents with VVS-CI (P<0.05): Pwd had a sensitivity of 69.77% and a specificity of 83.72% at the optimal cut-off value of 78.49 ms; Pmax had a sensitivity of 76.74% and a specificity of 90.70% at the optimal cut-off value of 93.39 ms; Pd had a sensitivity of 95.35% and a specificity of 69.77% at the optimal cut-off value of 27.42 ms; Pcmax had a sensitivity of 46.51% and a specificity of 88.37% at the optimal cut-off value of 120.90 ms; Pcd had a sensitivity of 83.72% and a specificity of 72.09% at the optimal cut-off value of 36.37 ms. Conclusions: Children and adolescents with VVS-CI have significantly increased Pwd, Pmax, Pd, Pcmax, and Pcd, which may indicate abnormal atrial electrical activity. The cut-off value of P wave has a certain diagnostic value in VVS-CI.

Coefficient of Variation of P-Wave Duration Is a Novel Atrial Heterogeneity Index to Predict Recurrence of Atrial Fibrillation After Catheter Ablation

Article

Jan 2016
J CARDIOVASC ELECTR

Introduction: Atrial conduction heterogeneity is associated with progression of atrial fibrillation (AF). However, the relationship between P-wave parameters representing atrial conduction heterogeneity and AF recurrence after catheter ablation (ABL) is still unclear. Methods and results: Subjects of the study were 126 consecutive patients with AF (78 paroxysmal and 48 persistent) who had received ABL. Coefficient of variation of P-wave duration (CV-PWD) was determined with all 12 surface electrocardiographic leads as an index of atrial conduction heterogeneity. Rates of freedom from AF recurrence were 78% and 77% in patients with paroxysmal and persistent AF, respectively, over a 12-month follow-up. CV-PWD measured before ABL was smaller in AF-free patients compared with AF-recurrent patients (0.089 ± 0.019 vs. 0.129 ± 0.042, p <0.001). CV-PWD significantly decreased after ABL in AF-free patients, but did not change in AF-recurrent patients. CV-PWD after ABL was also smaller in AF-free patients compared with AF-recurrent patients (0.087 ± 0.025 vs. 0.133 ± 0.035, p <0.001). In receiver operating curve analysis, CV-PWD measured before and after ABL achieved area under the curve of 0.829 and 0.854, respectively, for the ability to predict AF recurrence. CV-PWD correlated positively with left atrial (LA) diameter and negatively with LA appendage flow velocity. Conclusion: CV-PWD is a useful index to predict AF recurrence after ABL for both patients with paroxysmal and persistent AF. ABL may suppress AF by decreasing atrial conduction heterogeneity. This article is protected by copyright. All rights reserved.

On the resolution of ECG acquisition systems for the reliable analysis of the P-wave

Article

Jan 2012
PHYSIOL MEAS

The analysis of the P-wave on surface ECG is widely used to assess the risk of atrial arrhythmias. In order to provide reliable results, the automatic analysis of the P-wave must be precise and reliable and must take into account technical aspects, one of those being the resolution of the acquisition system. The aim of this note is to investigate the effects of the amplitude resolution of ECG acquisition systems on the P-wave analysis. Starting from ECG recorded by an acquisition system with a less significant bit (LSB) of 31 nV (24 bit on an input range of 524 mVpp), we reproduced an ECG signal as acquired by systems with lower resolution (16, 15, 14, 13 and 12 bit). We found that, when the LSB is of the order of 128 µV (12 bit), a single P-wave is not recognizable on ECG. However, when averaging is applied, a P-wave template can be extracted, apparently suitable for the P-wave analysis. Results obtained in terms of P-wave duration and morphology revealed that the analysis of ECG at lowest resolutions (from 12 to 14 bit, LSB higher than 30 µV) could lead to misleading results. However, the resolution used nowadays in modern electrocardiographs (15 and 16 bit, LSB <10 µV) is sufficient for the reliable analysis of the P-wave.

THe progression from hypertension to congestive heart failure

Article

Full-text available

May 1996

- To study the relative and population-attributable risks of hypertension for the development of congestive heart failure (CHF), to assess the time course of progression from hypertension to CHF, and to identify risk factors that contribute to the development of overt heart failure in hypertensive subjects. - Inception cohort study. - General community. - Original Framingham Heart Study and Framingham Offspring Study participants aged 40 to 89 years and free of CHF. To reflect more contemporary experience, the starting point of this study was January 1, 1970. EXPOSURE MEASURES:- Hypertension (blood pressure of at least 140 mm Hg systolic or 90 mm Hg diastolic or current use of medications for treatment of high blood pressure) and other potential CHF risk factors were assessed at periodic clinic examinations. - The development of CHF. - A total of 5143 eligible subjects contributed 72422 person-years of observation. During up to 20.1 years of follow-up (mean, 14.1 years), there were 392 new cases of heart failure; in 91% (357/392), hypertension antedated the development of heart failure. Adjusting for age and heart failure risk factors in proportional hazards regression models, the hazard for developing heart failure in hypertensive compared with normotensive subjects was about 2-fold in men and 3-fold in women. Multivariable analyses revealed that hypertension had a high population-attributable risk for CHF, accounting for 39% of cases in men and 59% in women. Among hypertensive subjects, myocardial infarction, diabetes, left ventricular hypertrophy, and valvular heart disease were predictive of increased risk for CHF in both sexes. Survival following the onset of hypertensive CHF was bleak; only 24% of men and 31% of women survived 5 years. - Hypertension was the most common risk factor for CHF, and it contributed a large proportion of heart failure cases in this population-based sample. Preventive strategies directed toward earlier and more aggressive blood pressure control are likely to offer the greatest promise for reducing the incidence of CHF and its associated mortality.

Profile for Estimating Risk of Heart Failure

Article

Full-text available

Jul 1999
ARCH INTERN MED

We devised a risk appraisal function to assess the hazard of heart failure in persons who are predisposed by coronary disease, hypertension, or valvular heart disease. To provide general practitioners and internists with a cost-effective method to select people at high risk who are likely to have impaired left ventricular systolic function and may therefore require further evaluation and aggressive preventive measures. The routinely measured risk factors used in constructing the heart failure profile include age, electrocardiographic left ventricular hypertrophy, cardiomegaly on chest x-ray film, heart rate, systolic blood pressure, vital capacity, diabetes mellitus, evidence of myocardial infarction, and valvular disease or hypertension. Based on 486 heart failure cases during 38 years of follow-up, 4-year probabilities of failure were computed using the pooled logistic regression model for each sex; a simple point score system was employed. A multivariate profile was also produced without the vital capacity or chest x-ray film because these may not be readily available in some clinical settings. Using the risk factors that make up the multivariate risk formulation-derived from ordinary office procedures-the probability of developing heart failure can be estimated and compared with the average risk for persons of the same age and sex. Using this risk profile, 60% of events in men and 73% in women occurred in subjects in the top quintile of multivariate risk. Using this multivariate risk formulation, it is possible to identify high-risk candidates for heart failure who are likely to have a substantial yield of positive findings when tested for objective evidence of presymptomatic left ventricular dysfunction. The risk profile may also identify candidates who are at high risk for heart failure because of multiple, marginal risk factor abnormalities that might otherwise be overlooked.

Increased P-Wave Duration and P-Wave Dispersion in Patients with Aortic Stenosis

Article

Full-text available

Feb 2003

P-wave dispersion (PWD), defined as the difference between the maximum and minimum P-wave duration, has been proposed as being useful for the prediction of paroxysmal atrial fibrillation (AF). AF is the most common arrhythmia and an important prognostic indicator for clinical deterioration in patients with aortic stenosis (AS). The aim of the present study was to evaluate PWD in patients with AS. The study population consisted of two groups: Group I consisted of 98 patients with AS (76 men, 22 women; aged 63 +/- 8 years) and group II consisted of 98 healthy subjects (same age and sex) without any cardiovascular disease. A 12-lead electrocardiogram was recorded for each subject. The P-wave duration was calculated in all leads of the surface electrocardiogram. The difference between the maximum and minimum P-wave duration was calculated and was defined as the PWD. All patients and control subjects were also evaluated by echocardiography to measure the left atrial diameter, left ventricular ejection fraction, left ventricular wall thicknesses, and the maximum and mean aortic gradients. Patients were also evaluated for the presence of paroxysmal AF. Maximum P-wave duration and PWD of group I were found to be significantly higher than those of group II. In addition, patients with paroxysmal AF had significantly higher PWD than those without paroxysmal AF. There was no significant difference between the two groups regarding minimum P-wave duration. In addition, there was no significant correlation between echocardiographic variables and PWD. PWD, indicating increased risk for paroxysmal AF, was found to be significantly higher in patients with AS than in those without it. Further assessment of the clinical utility of PWD for the prediction of paroxysmal AF in patients with severe AS will require longer prospective studies.

A Multicenter Risk Index for Atrial Fibrillation After Cardiac Surgery

Article

Full-text available

May 2004
J Am Med Assoc

Atrial fibrillation is a common, but potentially preventable, complication following coronary artery bypass graft (CABG) surgery. To assess the nature and consequences of atrial fibrillation after CABG surgery and to develop a comprehensive risk index that can better identify patients at risk for atrial fibrillation. Prospective observational study of 4657 patients undergoing CABG surgery between November 1996 and June 2000 at 70 centers located within 17 countries, selected using a systematic sampling technique. From a derivation cohort of 3093 patients, associations between predictor variables and postoperative atrial fibrillation were identified to develop a risk model, which was assessed in a validation cohort of 1564 patients. New-onset atrial fibrillation after CABG surgery. A total of 1503 patients (32.3%) developed atrial fibrillation after CABG surgery. Postoperative atrial fibrillation was associated with subsequent greater resource use as well as with cognitive changes, renal dysfunction, and infection. Among patients in the derivation cohort, risk factors associated with atrial fibrillation were advanced age (odds ratio [OR] for 10-year increase, 1.75; 95% confidence interval [CI], 1.59-1.93); history of atrial fibrillation (OR, 2.11; 95% CI, 1.57-2.85) or chronic obstructive pulmonary disease (OR, 1.43; 95% CI, 1.09-1.87); valve surgery (OR, 1.74; 95% CI, 1.31-2.32); and postoperative withdrawal of a beta-blocker (OR, 1.91; 95% CI, 1.52-2.40) or an angiotensin-converting enzyme (ACE) inhibitor (OR 1.69; 95% CI, 1.38-2.08). Conversely, reduced risk was associated with postoperative administration of beta-blockers (OR, 0.32; 95% CI, 0.22-0.46), ACE inhibitors (OR, 0.62; 95% CI, 0.48-0.79), potassium supplementation (OR, 0.53; 95% CI, 0.42-0.68), and nonsteroidal anti-inflammatory drugs (OR, 0.49; 95% CI, 0.40-0.60). The resulting multivariable risk index had adequate discriminative power with an area under the receiver operating characteristic (ROC) curve of 0.77 in the validation sample. Forty-three percent (640/1503) of patients who had atrial fibrillation after CABG surgery experienced more than 1 episode of atrial fibrillation. Predictors of recurrent atrial fibrillation included older age, history of congestive heart failure, left ventricular hypertrophy, aortic atherosclerosis, bicaval venous cannulation, withdrawal of ACE inhibitor or beta-blocker therapy, and use of amiodarone or digoxin (area under the ROC curve of 0.66). Patients with recurrent atrial fibrillation had longer hospital stays and experienced greater infectious, renal, and neurological complications than those with a single episode. We have developed and validated models predicting the occurrence of atrial fibrillation after CABG surgery based on an analysis of a large multicenter international cohort. Our findings suggest that treatment with beta-blockers, ACE inhibitors, and/or nonsteroidal anti-inflammatory drugs may offer protection. Atrial fibrillation after CABG surgery is associated with important complications.

P-wave duration and P-wave dispersion in patients with dilated cardiomyopathy

Article

Full-text available

Aug 2004

P-wave dispersion (PWD) has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. In the present study, we aimed to investigate PWD in patients with dilated cardiomyopathy. The study population consisted of 72 patients with dilated cardiomyopathy and 72 healthy control subjects. Left atrial diameter, left ventricular end-diastolic and end-systolic diameters and left ventricular ejection fraction of all patients and control subjects were measured by means of transthoracic echocardiography. Maximum P-wave duration (Pmaximum) and minimum P-wave duration (Pminimum) were measured from the 12-lead surface electrocardiogram. PWD was calculated as the difference between Pmaximum and Pminimum. Pmaximum and PWD of patients with dilated cardiomyopathy were significantly higher than those of control subjects (Pmaximum: 126+/-12 ms vs. 116+/-10 ms, PWD: 47+/-6 ms vs. 38+/-7 ms, respectively, P<0.001 for all). However, there was no statistically significant difference between patient group and control group regarding Pminimum (79+/-7 ms vs. 78+/-6 ms, respectively, P=0.27). Left atrial diameter was significantly higher in patients with dilated cardiomyopathy compared to control subjects (4.51+/-0.62 cm vs. 3.60+/-0.43 cm, respectively, P<0.001). Left ventricular ejection fraction was found to be significantly lower in patients with dilated cardiomyopathy compared to control subjects (33+/-5% vs. 63+/-7%, respectively, P<0.001). PWD was found to be significantly higher in patients with dilated cardiomyopathy than in healthy control subjects.

Implications of methodological differences in digital electrocardiogram interval measurement

Article

Full-text available

Nov 2006

Well-specified recommendations have yet to be established on how electrocardiogram (ECG) interval measurement should be performed by digital on-screen caliper systems to assess drug-induced effect on cardiac repolarization in pharmaceutical clinical trials with adequate precision and reproducibility. Since 1997, the industry has followed the European Committee for Proprietary Medicinal Products Points to Consider by using fully manual measurement of 3 consecutive sinus rhythm PQRST complexes in 1 lead only (typically limb lead II). More recently, semiautomatic measurement performed on representative (median) beats and based on the global leads has been considered. The International Conference on Harmonization E14 guidance (June 2005) advocates development of quality standards for centralized ECG interval measurement and allows all methods "whether or not assisted by computer" but includes no recommendations on how to perform the measurement. We provide an overview of the currently available methods for digital ECG interval measurement and the implications of between-method differences on quality of ECG interval measurements. We applied 4 methods most commonly used to assess QT prolongation (applied on 3 raw beats in limb lead II or by global measurement on 1 or 12 superimposed representative beats). QT, QTc Fridericia, and RR interval durations were measured on resting 12-lead digital ECGs obtained in 26 healthy volunteers predose and at 1, 2, and 3 hours after dosing with a single 160 mg oral dose of sotalol. Absolute interval durations and changes from baseline were compared between the 4 measurement methods. A better understanding of the implications from different measurement methodologies will facilitate more informed choice of the appropriate method for ECG interval measurement on clinical trials.

Assessment of Atrial Conduction in Patients with Scleroderma by Tissue Doppler Echocardiography and P Wave Dispersion

Article

Full-text available

Feb 2007
CARDIOLOGY

Atrial conduction abnormalities in patients with scleroderma have not been evaluated in terms of P wave duration, P wave dispersion (P(d)) and electromechanical coupling measured by tissue Doppler echocardiography. Twenty-four patients with scleroderma and 24 control subjects underwent resting electrocardiogram (ECG), M mode and tissue Doppler echocardiography. The P wave duration was calculated in all leads of the surface ECG. The difference between the maximum (P(max)) and minimum P wave duration was calculated and defined as P(d). Interatrial and intraatrial electromechanical delays were measured with tissue Doppler tissue echocardiography. The left ventricular dimensions, fractional shortening, and left atrial diameter did not differ between the patients and the controls. P(d) and P(max) were significantly higher in patients with scleroderma compared with controls: 51 +/- 17 versus 28 +/- 7 ms (p < 0.01) and 109 +/- 10 versus 93 +/- 6 ms (p < 0.01), respectively. There was a delay between the onset of the P wave on surface ECG and the onset of the late diastolic wave (A wave; PA) obtained by tissue Doppler echocardiography in patients with scleroderma compared with controls measured at lateral septal annulus (lateral PA; 122 +/- 8 vs. 105 +/- 7 ms, p = 0.001), septal mitral annulus (104 +/- 11 vs. 93 +/- 10 ms, p = 0.01) and tricuspid annulus (right ventricular PA; 71 +/- 9 vs. 64 +/- 7 ms, p = 0.05). Interatrial conduction time (lateral PA - right ventricular PA) was delayed in patients with scleroderma compared with controls (88 +/- 13 vs. 76 +/- 11 ms, p = 0.01). A positive correlation was detected between interatrial electromechanical delay (lateral PA - right ventricular PA) and P(d) (r = 0.5, p = 0.03). Atrial conduction abnormalities as estimated with P(d) and P(max) are significantly higher in patients with scleroderma compared with controls. There is a delay in both intraatrial and interatrial electromechanical coupling intervals in patients with scleroderma.

Recommendations for the Standardization and Interpretation of the Electrocardiogram. Part I: The Electrocardiogram and Its Technology A Scientific Statement From the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society Endorsed by...

Article

Full-text available

Apr 2007

This statement examines the relation of the resting ECG to its technology. Its purpose is to foster understanding of how the modern ECG is derived and displayed and to establish standards that will improve the accuracy and usefulness of the ECG in practice. Derivation of representative waveforms and measurements based on global intervals are described. Special emphasis is placed on digital signal acquisition and computer-based signal processing, which provide automated measurements that lead to computer-generated diagnostic statements. Lead placement, recording methods, and waveform presentation are reviewed. Throughout the statement, recommendations for ECG standards are placed in context of the clinical implications of evolving ECG technology.

An Investigation of Coronary Heart Disease in Families: The Framingham Offspring Study

Article

Jun 2017
AM J EPIDEMIOL

The Framingham Heart Study (FHS) was started in 1948 as a prospective investigation of cardiovascular disease in a cohort of adult men and women. Continuous surveillance of this sample of 5209 subjects has been maintained through biennial physical examinations. In 1971 examinations were begun on the children of the FHS cohort. This study, called the Framingham Offspring Study (FOS), was undertaken to expand upon knowledge of cardiovascular disease, particularly in the area of familial clustering of the disease and its risk factors. This report reviews the sampling design of the FHS and describes the nature of the FOS sample. The FOS families appear to be of typical size and age structure for families with parents born in the late 19th or early 20th century. In addition, there is little evidence that coronary heart disease (CHD) experience and CHO risk factors differ in parents of those who volunteered for this study and the parents ot those who did not volunteer.

An investigation of coronary heart disease in families. The Framingham offspring study

Article

Sep 1979
AM J EPIDEMIOL

The Framingham Heart Study (FHS) was started in 1948 as a prospective investigation of cardiovascular disease in a cohort of adult men and women. Continuous surveillance of this sample of 5209 subjects has been maintained through biennial physical examinations. In 1971 examinations were begun on the children of the FHS cohort. This study, called the Framingham Offspring Study (FOS), was undertaken to expand upon knowledge of cardiovascular disease, particularly in the area of familial clustering of the disease and its risk factors. This report reviews the sampling design of the FHS and describes the nature of the FOS sample. The FOS families appear to be of typical size and age structure for families with parents born in the late 19th or early 20th century. In addition, there is little evidence that coronary heart disease (CHD) experience and CHD risk factors differ in parents of those who volunteered for this study and the parents of those who did not volunteer.

The PR Interval is a Heritable Quantitative Trait with Evidence for Linkage to Chromosome 4 in a Genome-Wide Scan: the Framingham Heart Study

Article

Mar 2001

P19 Introduction: Delayed atrioventricular conduction on the electrocardiogram (ECG), manifested by PR interval prolongation, can progress to heart block. Both heart-rate slowing drugs and environmental factors may lead to PR interval prolongation; however, the heritability of the PR interval has not been studied in the general population and genetic variants in the regulation of PR duration have not been characterized. Methods: We examined the heritability of the PR interval and we tested for evidence of linkage of the PR interval to chromosomal regions in a large population-based cohort. 12-lead ECGs were obtained routinely in adult Framingham Heart Study participants as part of the clinic examination. The PR interval was measured using digital calipers. We conducted a 10 cM genome wide scan in 328 extended families (1688 genotyped subjects, 2257 phenotyped subjects, 2028 phenotyped sibling pairs). Variance component methods were used to estimate heritability and to perform linkage analysis. Results: The PR interval (adjusted for age and RR-interval) was heritable [h 2 0.32 (95% confidence interval 0.26-0.37)]. The highest multipoint LOD score for the adjusted PR interval was found on chromosome 4 (LOD score was 2.16 at 123 cM). The next highest LOD score was 1.88 (chromosome 17 at 59 cM). Conclusion: These results suggest there are influential genetic regions contributing to variability in PR interval in the general population. Defining genetic determinants of PR duration may provide insights into the pathophysiology of heart block and may help identify persons with a high susceptibility to drug-induced heart block.

The Progression From Hypertension to Congestive Heart Failure

Article

May 1996

Daniel Levy

Objective. —To study the relative and population-attributable risks of hypertension for the development of congestive heart failure (CHF), to assess the time course of progression from hypertension to CHF, and to identify risk factors that contribute to the development of overt heart failure in hypertensive subjects.Design. —Inception cohort study.Setting. —General community.Participants. —Original Framingham Heart Study and Framingham Offspring Study participants aged 40 to 89 years and free of CHF. To reflect more contemporary experience, the starting point of this study was January 1, 1970.Exposure Measures. —Hypertension (blood pressure of at least 140 mm Hg systolic or 90 mm Hg diastolic or current use of medications for treatment of high blood pressure) and other potential CHF risk factors were assessed at periodic clinic examinations.Outcome Measure. —The development of CHF.Results. —A total of 5143 eligible subjects contributed 72422 person-years of observation. During up to 20.1 years of follow-up (mean, 14.1 years), there were 392 new cases of heart failure; in 91% (357/392), hypertension antedated the development of heart failure. Adjusting for age and heart failure risk factors in proportional hazards regression models, the hazard for developing heart failure in hypertensive compared with normotensive subjects was about 2-fold in men and 3-fold in women. Multivariable analyses revealed that hypertension had a high population-attributable risk for CHF, accounting for 39% of cases in men and 59% in women. Among hypertensive subjects, myocardial infarction, diabetes, left ventricular hypertrophy, and valvular heart disease were predictive of increased risk for CHF in both sexes. Survival following the onset of hypertensive CHF was bleak; only 24% of men and 31% of women survived 5 years.Conclusions. —Hypertension was the most common risk factor for CHF, and it contributed a large proportion of heart failure cases in this population-based sample. Preventive strategies directed toward earlier and more aggressive blood pressure control are likely to offer the greatest promise for reducing the incidence of CHF and its associated mortality.(JAMA. 1996;275:1557-1562)

A multicenter risk index for AF after cardiac surgery

Article

Jun 2004

Increased Variance of P Wave Duration on the Electrocardiogram Distinguishes Patients with Idiopathic Paroxysmal Atrial Fibrillation

Article

Jul 2000
PACE

We hypothesized that the variance of P wave duration (P variance) in the 12-lead ECG could reflect the spatial dispersion of P wave duration due to inhomogeneous and delayed propagation of sinus impulses in the atria, and moreover could present better reproducibility than maximum P wave duration and P wave dispersion that have already been used for the prediction of idiopathic paroxysmal AF, We also tested a semiautomated PC-based method to improve the accuracy and reproducibility of P wave measurements. A 12-lead ECG was obtained from 60 patients with idiopathic paroxysmal AF and from 50 healthy controls. All ECGs were analyzed manually using magnifying lens and calipers, while 20 randomly selected ones were scanned and analyzed on screen using common commercial software. P maximum, P dispersion, and P variance were all significantly higher in patients with paroxysmal AF than in controls. A P maximum value of 110 ms, a P dispersion value of 40 ms, and a P variance value of 120 ms2 separated patients from controls with a sensitivity of 88%, 83%, and 80%, respectively and a specificity of 75%, 85%, and 74%, respectively. The reproducibility of P variance was higher compared to P dispersion and P maximum. Finally, the PC-based method significantly increased accuracy and reproducibility of P wave measurements. Thus, the variance of P wave duration could be a useful ECG marker for the prediction of paroxysmal idiopathic AF and the use of PC-based methods may enhance the accurate measuring of P wave duration on the ECG.

P Wave Dispersion on 12‐Lead Electrocardiography in Patients with Paroxysmal Atrial Fibrillation

Article

Jul 2000
PACE

The prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses have been shown in patients with atrial fibrillation. Recently P wave dispersion (PWD), which is believed to reflect inhomogeneous atrial conduction, has been proposed as being useful for the prediction of paroxysmal atrial fibrillation (PAF). Ninety consecutive patients (46 men, 44 women; aged 55 ± 13 years) with a history of idiopathic PAF and 70 healthy subjects (42 men, 28 women; mean age, 53 ± 14 years) were studied. The P wave duration was calculated in all 12 leads of the surface ECC. The difference between the maximum and minimum P wave duration was calculated and this difference was defined as P wave dispersion (PWD = Pmax - Pmin). All patients and controls were also evaluated by echocardiography to measure the left atrial diameter and left ventricular ejection fraction (LVEF). There was no difference between patients and controls in gender (P = 0.26), age (P = 0.12), LVEF (66 ± 4% vs 67 ± 5%, P = 0.8) and left atrial diameter (36 ± 4 mm vs 34 ± 6 mm, P = 0.13). P maximum duration was found to be significantly higher in patients with a history of PAF (116 ± 17 ms) than controls (101 ±11 ms. P < 0.001). P wave dispersion was also significantly higher in patients than in controls (44 ± 15 ms vs 27 ± 10 ms, P < 0.001). There was a weak correlation between age and P wave dispersion (r = 0.27, P < 0.001). A P maximum value of 106 ms separated patients with PAF from control subjects with a sensitivity of 83%, a specificity of 72%, and a positive predictive accuracy of 79%. A P wave dispersion value of 36 ms separated patients from control subjects with a sensitivity of 77%, a specificity of 82%, and a positive predictive accuracy of 85%. In conclusion, P maximum duration and P wave dispersion calculated on a standard surface ECG are simple ECG markers that could be used to identify the patients with idiopathic paroxysmal atrial fibrillation.

Uncertainty and Trend Analysis—Radium in Ground Water and Drinking Water

Article

Sep 2007
GROUND WATER MONIT R

Radium activity measurements in water samples are encumbered by relatively large error bars, including for activity values near the regulatory drinking water maximum contaminant level of 5 pCi/L. The large error bars create uncertainty in the evaluation of temporal trends. This uncertainty is often the object of debate and disagreement in regulatory determinations, the design of remedial actions, and/or in litigation. The Mann-Kendall nonparametric test is perhaps the most commonly used test for trend evaluation in environmental sciences. The test is simple and easy to apply by nonstatisticians and is recommended in several regulations and guidance documents. As typically applied, the Mann-Kendall test does not consider the uncertainty related to error bars for individual data values. Ignoring this uncertainty can result in misleading conclusions on the presence or absence of trends. In this article, a procedure for trend analysis that accounts for error bars is described. For each data series analyzed, the procedure creates 1000 new data series by randomly assigning values that fall within the error bar around each data point. Trend analysis is then performed on the randomly created data series. The approach is applied to the evaluation of a radium data base containing analytical results from 137 locations (407 water samples) in Escambia County, Florida. The evaluation of the radium data base using the Mann-Kendall test without accounting for the uncertainty reveals 10 significant trends at the 90% confidence level. Only two of these trends are supported by the data when the uncertainty from analytical error is accounted for.

P Wave Indices Current Status and Future Directions in Epidemiology, Clinical, and Research Applications

Article

Feb 2009
CIRC-ARRHYTHMIA ELEC

P wave indices have been applied in a wide range of clinical contexts. They have been associated with clinical risk factors for AF, recurrence and incident AF in small to moderate sized referral cohorts of individuals with risk factors, structural heart disease or undergoing cardiothoracic surgery. The current research on P wave indices has been limited by studies with modest sample size, cross-sectional or limited follow-up, and lack of accounting for confounders. Most studies referenced in Table 1 have less than 100 subjects. Despite the volume of studies, P wave indices reference ("normal") values have not been standardized. P wave duration cut-offs of 110 or 120 ms have been proposed, but the large prevalence of hospitalized patients found to meet these criteria suggests a low specificity and poor screening utility. No prospective, community-based study has developed reference values by identifying a reference population, articulating measurements of indices, and then applying those measurements to a broad sample with cardiovascular disease, risk factors, and the covariates identified here. Measurement techniques have not been standardized. Investigators continue to use magnification and hand-held calipers, yet have reported measuring P wave duration to the hundredth of a millisecond with this technique. A single study compared measurement techniques and found improved quality control with digitized measurements.44 Quality control assessments have been limited. Most investigators used measurements surrounding the mean, potentially inflating reproducibility. Robust statistical measures for vigorous quality control are lacking. The deficits of standardized techniques and quality control severely limit the application of P wave indices. Substantive questions remain concerning the correlations of calculated P wave indices and invasive electrophysiological studies. Agreement between these 2 methods will be essential to verify the validity of P wave indices. There has not been adequate comparison of SAECG and P wave indices. Finally, interlead heterogeneity has not been incorporated into the assessment of P wave indices.

Kannel WB, Feinleib M, McNamara PM, Garrison RJ, Castelli WP. An investigation of coronary heart disease in families. The Framingham Offspring Study. Am J Epidemiol 110, 281-290

Article

Oct 1979
AM J EPIDEMIOL

The Framingham Heart Study (FHS) was started in 1948 as a prospective investigation of cardiovascular disease in a cohort of adult men and women. Continuous surveillance of this sample of 5209 subjects has been maintained through biennial physical examinations. In 1971 examinations were begun on the children of the FHS cohort. This study, called the Framingham Offspring Study (FOS), was undertaken to expand upon knowledge of cardiovascular disease, particularly in the area of familial clustering of the disease and its risk factors. This report reviews the sampling design of the FHS and describes the nature of the FOS sample. The FOS families appear to be of typical size and age structure for families with parents born in the late 19th or early 20th century. In addition, there is little evidence that coronary heart disease (CHD) experience and CHD risk factors differ in parents of those who volunteered for this study and the parents of those who did not volunteer.

Electrocardiographic detection of left ventricular hypertrophy by the simple QRS voltage-duration product

Article

Nov 1992
J AM COLL CARDIOL

The object of this study was to assess the hypothesis that the product of QRS voltage and duration, as an approximation of the time-voltage integral of the QRS complex, can improve the electrocardiographic (ECG) identification of left ventricular hypertrophy. Electrocardiographic identification of left ventricular hypertrophy has been limited by the poor sensitivity of standard voltage criteria. However, increases in left ventricular mass can be more closely related to increases in the time-voltage integral of the summed left ventricular dipole than to changes in voltage or QRS duration alone. Antemortem ECGs were compared with left ventricular mass at autopsy in 220 patients. There were 95 patients with left ventricular hypertrophy, defined by left ventricular mass index > 118 g/m2 in men and > 104 g/m2 in women. The voltage-duration product was calculated as the product of QRS duration and Cornell voltage (Cornell product) and the 12-lead sum of QRS voltage (12-lead product). At partitions with a matched specificity of 95%, each voltage-duration product significantly improved sensitivity for the detection of left ventricular hypertrophy when compared with simple voltage criteria alone (Cornell product 51% [48 of 95] vs. Cornell voltage 36% [34 of 95], p < 0.005 and 12-lead product 45% [43 of 95] vs. 12-lead voltage 31% [30 of 95], p < 0.001). Sensitivity of both the Cornell product and 12-lead product was significantly greater than that found for QRS duration alone (28%, 27 of 95, p < 0.005) and the Romhilt-Estes point score (27%, 26 of 95, p < 0.005), and compared favorably with the sensitivity of the complex Cornell multivariate score (44%, 42 of 95, p = NS). Comparison of receiver operating characteristic curves demonstrated that improved performance of the voltage-duration products for the detection of left ventricular hypertrophy was independent of test partition selection. In addition, test performance of the voltage-duration products was not significantly affected by the presence or absence of a bundle branch block. These data suggest that the simple product of either Cornell or 12-lead voltage and QRS duration can identify left ventricular hypertrophy more accurately than can voltage or QRS duration criteria alone and may approach or exceed the performance of more complex multiple regression analyses.

An improved method for adjusting the QT interval for heart rate (The Framingham Heart Study)

Article

Oct 1992
AM J CARDIOL

Several formulas have been proposed to adjust the QT interval for heart rate, the most commonly used being the QT correction formula (QTc = QT/square root of RR) proposed in 1920 by Bazett. The QTc formula was derived from observations in only 39 young subjects. Recently, the adequacy of Bazett's formula has been questioned. To evaluate the heart rate QT association, the QT interval was measured on the initial baseline electrocardiogram of 5,018 subjects (2,239 men and 2,779 women) from the Framingham Heart Study with a mean age of 44 years (range 28 to 62). Persons with coronary artery disease were excluded. A linear regression model was developed for correcting QT according to RR cycle length. The large sample allowed for subdivision of the population into sex-specific deciles of RR intervals and for comparison of QT, Bazett's QTc and linear corrected QT (QTLC). The mean RR interval was 0.81 second (range 0.5 to 1.47) heart rate 74 beats/min (range 41 to 120), and mean QT was 0.35 second (range 0.24 to 0.49) in men and 0.36 second (range 0.26 to 0.48) in women. The linear regression model yielded a correction formula (for a reference RR interval of 1 second): QTLC = QT + 0.154 (1-RR) that applies for men and women. This equation corrects QT more reliably than the Bazett's formula, which overcorrects the QT interval at fast heart rates and undercorrects it at low heart rates. Lower and upper limits of normal QT values in relation to RR were generated.(ABSTRACT TRUNCATED AT 250 WORDS)

Probability of Stroke: A Risk Profile from the Framingham Study

Article

Apr 1991

A health risk appraisal function has been developed for the prediction of stroke using the Framingham Study cohort. The stroke risk factors included in the profile are age, systolic blood pressure, the use of antihypertensive therapy, diabetes mellitus, cigarette smoking, prior cardiovascular disease (coronary heart disease, cardiac failure, or intermittent claudication), atrial fibrillation, and left ventricular hypertrophy by electrocardiogram. Based on 472 stroke events occurring during 10 years' follow-up from biennial examinations 9 and 14, stroke probabilities were computed using the Cox proportional hazards model for each sex based on a point system. On the basis of the risk factors in the profile, which can be readily determined on routine physical examination in a physician's office, stroke risk can be estimated. An individual's risk can be related to the average risk of stroke for persons of the same age and sex. The information that one's risk of stroke is several times higher than average may provide the impetus for risk factor modification. It may also help to identify persons at substantially increased stroke risk resulting from borderline levels of multiple risk factors such as those with mild or borderline hypertension and facilitate multifactorial risk factor modification.

Electrocardiographic identification of increased left ventricular mass by simple voltage-duration products

Article

Feb 1995
J AM COLL CARDIOL

This study was conducted to validate the hypothesis that the product of QRS voltage and duration, as an approximation of the time-voltage area of the QRS complex, can improve the electrocardiographic (ECG) detection of echocardiographically determined left ventricular hypertrophy and to further assess the relative contribution of QRS duration to the ECG detection of hypertrophy. The ECG identification of left ventricular hypertrophy has been limited by the poor sensitivity of standard voltage criteria alone. However, increases in left ventricular mass can be more accurately related to increases in the time-voltage area of the QRS complex than to changes in QRS voltage or duration alone. Standard 12-lead ECGs and echocardiograms were obtained for 389 patients, including 116 patients with left ventricular hypertrophy. Simple voltage-duration products were calculated by multiplying Cornell voltage by QRS duration (Cornell product) and the 12-lead sum of voltage by QRS duration (12-lead product). In a stepwise logistic regression model that also included Cornell voltage, Sokolow-Lyon voltage, age and gender, QRS duration remained a highly significant predictor of the presence of left ventricular hypertrophy (chi-square 26.9, p < 0.0001). At a matched specificity of 96%, each voltage-duration product significantly improved sensitivity for the detection of left ventricular hypertrophy compared with simple voltage criteria alone (Cornell product 37% vs. Cornell voltage 28%, p < 0.02, and 12-lead product 50% vs. 12-lead voltage 43%, p < 0.005). Sensitivities of both the Cornell product and the 12-lead product were significantly greater than the 27% sensitivity of QRS duration alone (p < 0.01 vs. p < 0.001), the 20% sensitivity of a Romhilt-Estes point score > 4 (p < 0.001) and the 33% sensitivity of the best-fit logistic regression model in this cohort (p < 0.05 vs. p < 0.001). QRS duration is an independent ECG predictor of the presence of left ventricular hypertrophy, and the simple product of either Cornell voltage or 12-lead voltage and QRS duration significantly improves identification of left ventricular hypertrophy relative to other ECG criteria that use QRS duration and voltages in linear combinations.

Gender Differences and the Electrocardiogram in Left Ventricular Hypertrophy

Article

Mar 1995

We examined the relations of gender differences in electrocardiographic (ECG) voltages and QRS duration to differences in cardiac dimensions and body size between men and women and gender differences in test performance of ECG criteria for the detection of echocardiographic left ventricular hypertrophy in 389 subjects (112 women and 277 men). ECG voltage-duration products were calculated as the product of QRS duration and voltages. Among subjects with normal left ventricular mass and also among subjects with left ventricular hypertrophy, men had longer QRS duration, higher Cornell voltage, higher 12-lead sum of QRS voltage, and higher Cornell and 12-lead voltage-duration products than did women. Significant gender differences in QRS duration, Cornell voltage, the 12-lead sum of voltage and their voltage-duration products remained after adjusting for the greater left ventricular mass, height, and weight in men than women. Comparison of areas under receiver operating characteristic curves using gender-specific criteria demonstrated higher performance of QRS duration, Cornell voltage, the 12-lead sum of QRS voltage, and the respective voltage-duration products for the identification of left ventricular hypertrophy in men than women. Thus, gender differences in body size and left ventricular mass do not completely account for gender differences in QRS duration and voltage measurements, and ECG criteria for left ventricular hypertrophy have lower accuracy in women even when gender differences in partition value selection are taken into account.(ABSTRACT TRUNCATED AT 250 WORDS)

Simple electrocardiographic markers for the prediction of paroxysmal atrial fibrillation

Article

Jun 1998
AM HEART J

The prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses are well known electrophysiologic characteristics in patients with paroxysmal atrial fibrillation (PAF). To search for possible electrocardiographic markers that could serve as predictors of idiopathic PAF, we measured the maximum P-wave duration (P maximum) and the difference between the maximum and the minimum P-wave duration (P dispersion) from the 12-lead surface electrocardiogram of 60 patients with a history of idiopathic PAF and 40 age-matched healthy control subjects. P maximum and P dispersion were found to be significantly higher in patients with idiopathic PAF than in control subjects. A P maximum value of 110 msec and a P dispersion value of 40 msec separated patients from control subjects, with a sensitivity of 88% and 83% and a specificity of 75% and 85%, respectively. P maximum and P dispersion are simple electrocardiographic markers that could be used for the prediction of idiopathic PAF.

The role of P wave in prediction of atrial fibrillation after coronary artery surgery

Article

Mar 1999
INT J CARDIOL

Atrial fibrillation (AF) is a common arrhythmia after coronary artery bypass surgery (CABG). The purpose of this study was to determine the role of P wave duration, amplitude and dispersion in the prediction of AF after CABG. This study included 120 patients undergoing elective CABG. Clinical characteristics, 12-lead electrocardiogram (ECG), echocardiogram and coronary angiogram were obtained in all patients. We measured P wave duration, amplitude and dispersion from 12-lead ECG in each patient. After CABG, all patients were continuously monitored for AF attacks in the intensive care unit and ordinary ward. Our results showed that age greater than 60 years was the strongest predictor of postoperative AF (p<0.01), with a 3.7-fold greater likelihood of developing postoperative AF compared to ages less than 60 years. Gender was another independent predictor of postoperative AF, with men being 3.0 times more likely to develop postoperative AF compared to women (p = 0.03). The presence of prolonged P wave duration (> or =100 ms in lead II) was also an independent predictor (p = 0.04), with 2.9-fold greater risk of developing postoperative AF compared to a P wave duration of less than 100 ms. The P wave dispersion was similar between patients with and without postoperative AF (29+/-15 vs. 33+/-15 mm, p = NS). In conclusion, old age, male gender and prolonged P wave duration were independent predictors of AF after CABG. However, P wave dispersion and amplitude did not provide significant information in the prediction of postoperative AF.

Clinical study to investigate parameters for the onset of atrial fibrillation in patients with essential hypertension

Article

Jun 2000
AM HEART J

Background: The risk factors involved in the onset of atrial fibrillation (AF) are well known, but the predictive clinical and paraclinical parameters for the onset of AF in hypertensive patients have not been investigated specifically. Methods and results: We retrospectively analyzed 97 consecutive patients with hypertension and no known history of AF or cardiovascular events who attended the cardiology outpatient clinic. The analysis was based on clinical data, the noninvasive ambulatory 24-hour measurement of blood pressure (AMBP), a standard 12-lead electrocardiogram, and a Doppler echocardiogram. After a mean follow-up of 25 +/- 3 months, 19 (19. 5%) patients had AF, 3 (15.8%) of whom had a cerebrovascular accident. The patients with AF were older than the others and their AMBP showed higher mean systolic diurnal and nocturnal blood pressures, though no differences in the clinical blood pressure readings were present. On the electrocardiogram, the maximum duration of the P wave and its dispersion were more prolonged in the patients with AF. On the Doppler echocardiogram, left ventricular mass and left atrial dimension were higher in the patients with AF, and the A-wave velocity of diastolic mitral flow was reduced in these patients. In the multivariate analysis, age (odds ratio 3.28, P <.001), diurnal systolic blood pressure (odds ratio 1.35, P <.01) and nocturnal systolic blood pressure (odds ratio 1.16, P <.01), maximum duration of the P wave (odds ratio 2.09, P <.01), dispersion of the P wave (odds ratio 2.52, P <.001), echocardiographic left ventricular mass (odds ratio 1.43, P <.01), left atrial dimension (odds ratio 2.81, P <.001), and velocity of the A wave (odds ratio 2. 24, P <.01) were independent predictors for the onset of AF. After correction for age, maximum duration of the P wave (odds ratio 1.34, P <.01), dispersion of the P wave (odds ratio 1.63, P <.001), and the velocity of the A wave (odds ratio 1.42, P <.01) remained independent predictors for the onset of AF. Conclusions: In patients with hypertension, age and the level of diurnal and nocturnal systolic blood pressures measured by 24-hour AMBP are important independent predictors for the onset of AF. Independent of age, increases in left atrial dimension and left ventricular mass, prolongation of the maximum duration and dispersion of the P wave and reduced A-wave velocity are also predictors for the onset of AF.

P-Wave Dispersion: A Novel Predictor of Paroxysmal Atrial Fibrillation

Article

May 2001

The prolongation of intraatrial and interatrial conduction time and the inhomogeneous propagation of sinus impulses are well known electrophysiologic characteristics in patients with paroxysmal atrial fibrillation (AF). Previous studies have demonstrated that individuals with a clinical history of paroxysmal AF show a significantly increased P-wave duration in 12-lead surface electrocardiograms (ECG) and signal-averaged ECG recordings. The inhomogeneous and discontinuous atrial conduction in patients with paroxysmal AF has recently been studied with a new ECG index, P-wave dispersion. P-wave dispersion is defined as the difference between the longest and the shortest P-wave duration recorded from multiple different surface ECG leads. Up to now the most extensive clinical evaluation of P-wave dispersion has been performed in the assessment of the risk for AF in patients without apparent heart disease, in hypertensives, in patients with coronary artery disease and in patients undergoing coronary artery bypass surgery. P-wave dispersion has proven to be a sensitive and specific ECG predictor of AF in the various clinical settings. However, no electrophysiologic study has proven up to now the suspected relationship between the dispersion in the atrial conduction times and P-wave dispersion. The methodology used for the calculation of P-wave dispersion is not standardized and more efforts to improve the reliability and reproducibility of P-wave dispersion measurements are needed. P-wave dispersion constitutes a recent contribution to the field of noninvasive electrocardiology and seems to be quite promising in the field of AF prediction.

Factors Associated with the Development of Atrial Fibrillation in COPD Patients: The Role of P‐Wave Dispersion

Article

Aug 2002

Supraventricular tachyarrhythmia is a common problem in chronic obstructive pulmonary disease (COPD) patients. The purpose of this study is to analyze the factors associated with paroxysmal atrial fibrillation (AF) in COPD patients. Forty COPD patients (38 male, 2 female, mean age 60 +/- 9 years) and 33 healthy controls (29 male, 4 female, mean age: 58 +/- 10 years) were included in this study. Echocardiography, 24-hour ambulatory and 12-lead ECG, pulmonary function tests, arterial blood gases, and serum electrolytes were measured. On ECG, maximum (P(max)) and minimum (P(min)) duration of P wave and its difference, P-wave dispersion (PWd), were measured. On echocardiography, diastolic dysfunction was found in 14 of the 40 (35%) COPD patients. Heart rate variability analysis revealed that COPD patients had decreased SDANN, SDNN, SDNNIDX in time-domain, and decreased LF in frequency domain parameters. Fourteen of the 40 COPD patients (35%) had AF. Patients with AF were older (57 +/- 10 vs 64 +/- 5 years, P = 0.03) and had lower SDANN, SDNN, and LF/HF ratio as compared to patients without AF in univariate analysis. All P-wave intervals (P(max), P(min,) and PWd) were increased in COPD patients compared to controls. P-wave dispersion was significantly increased in COPD patients with AF, as compared to patients without AF (57 +/- 11 vs 44 +/- 7 ms, P = 0.001). In logistic regression analysis PWd was found to be the only factor associated with the development of AF (P = 0.04). The presence of AF was significantly related to the prolongation of PWd, but not with pulmonary function, arterial blood gasses, and left and right atrial function.

Prevalence of Interatrial block in a general hospital population.

Article

Apr 2003
AM J CARDIOL

The present investigation showed a very high prevalence of IAB in a hospital population. Above the age of 60 years, more patients in sinus rhythm had IAB than those without it. Considering the consequences of atrial fibrillation, including subsequent stroke in such patients, it is essential that IAB be recognized early because it is associated with a higher incidence of abnormalities in atrial excitability 10 and significant electromechanical dysfunction of the left atrium. 5,6 .

P Wave Analysis Indices in Young Healthy Men: Data from the Digital Electrocardiographic Study in Hellenic Air Force Servicemen (DEHAS)

Article

Jan 2003

P wave analysis from the 12-lead ECG is a recent contribution of noninvasive electrocardiology. P wave analysis indices (maximum and minimum P wave duration, P wave dispersion [Pdis = Pmax-Pmin], adjusted P wave dispersion [APdis = Pdis/square root of measured leads], summated P wave duration [Psum], standard deviation of P wave duration [Psd], mean P wave duration [Pmean]) can predict atrial arrhythmias. However, the definitions of all these indices are based on few studies. The aim of this analysis was to define normal values of these indices and the examine possible associations between P wave indices and clinical variables. The study included 1,353 healthy men, 24 +/- 3 years of age, who answered a questionnaire and underwent a detailed physical examination and a digitized 12-lead surface ECG. All P wave indices were analyzed by two independent investigators. Mean values of the ECG indices were: Pmax: 96 +/- 11 ms, Pmin: 57 +/- 9 ms, Pdis: 38 +/- 10 ms, Psum: 924 +/- 96 ms, Psd: 12 +/- 3, APdis: 11 +/- 3 ms, and Pmean: 77 +/- 8 ms. Age was significantly related with Pmax (r = 0.277, P < 0.01), Pmin (r = 0.255, P < 0.001), Psum (r = 0.074, P < 0.01), and Pmean (r = 0.074, P < 0.01). All ECG indices were significantly associated with the R-R interval, and among each other. This study defined normal indices of wave duration and correlations among them. These markers may play an important predictive role in patients with atrial conduction abnormalities.

Evaluation of P wave duration and P wave dispersion in adult patients with secundum atrial septal defect during normal sinus rhythm

Article

Sep 2003
INT J CARDIOL

Paroxysmal atrial arrhythmias especially atrial fibrillation (AF) are frequently encountered in adult patients with atrial septal defect (ASD). Previously it was shown that maximum P wave duration and P wave dispersion in 12-lead surface electrocardiograms are significantly increased in individuals with a history of paroxysmal AF. The aim of this study was to determine whether P maximum and P dispersion in adult patients with ASD and without AF are increased as compared to healthy controls. In addition, the relationship of pulmonary to systemic flow ratio (Qp/Qs) and these P wave indices were investigated. Sixty-two consecutive patients [39 women, 23 men; mean age 33+/-13 years (range 16 to 61 years)] with ostium secundum type ASD and 47 healthy subjects [25 women, 22 men; mean age 36.6+/-9.5 years (range 18 to 50 years)] were investigated. P maximum, P minimum and P dispersion (maximum minus minimum P wave duration) were measured from the 12-lead surface ECG. There were no significant differences with respect to age (P=0.08), gender (P=0.3), heart rate (P=0.3), left atrial diameter (P=0.5) and left ventricular ejection fraction (P=0.3) between patients and controls. Pulmonary artery peak systolic pressure was significantly higher in patients with ASD as compared to controls (P<0.0001). P maximum was significantly longer in patients with ASD as compared to controls (P<0.0001). In addition, P dispersion of the patients was significantly higher than controls (P=0.001). P minimum was not different between groups (P=0.12). Mean Qp/Qs of the patients with ASD was 2.5+/-0.7 (minimum 1.5; maximum 4.1) and found to be significantly correlated with P maximum (r=0.34; P=0.006) and P dispersion (r=0.61; P<0.0001). Prolongation of P maximum and increased P dispersion could represent mechanical and electrical changes of atrial myocardium in patients with ASD. These changes of atrial myocardium may be more prominent with higher left to right shunt volumes.

The Effect of Exercise to P Wave Dispersion and Its Evaluation as a Predictor of Atrial Fibrillation

Article

Oct 2003

Prolongation of P wave time and increase of its dispersion as an independent predictor of atrial fibrillation. In patients with paroxysmal atrial fibrillation (PAF) as in healthy people, exercise augments sympathetic activity and therefore can cause the development of atrial fibrillation. The aim of this study is to evaluate the effect of exercise on P wave dispersion and to predict the development of atrial fibrillation. One hundred and ninety-eight patients (93 women, 105 men, mean age: 59.05 +/- 11.01 years) having the diagnosis of PAF were included in the study. The left atrial diameter of all these patients was more than 4.0 cm. One hundred and fifty-five patients (72 females, 83 males, mean age: 58.41 +/- 10.79 years), with left atrial diameter more than 4.0 cm and without PAF were taken as control group. Symptom limited exercise test with modified Bruce protocol was performed on all patients. Rest, maximum exercise and recovery, and first, third, and fifth-minute 12-derivation ECG was taken in all patients. The velocity of ECG was adjusted to 50 mm/s; shortest and largest P wave durations were measured and P wave dispersion was calculated. The mean left atrial diameter was 4.41 +/- 0.58 cm in PAF patients and 4.38 +/- 0.48 cm in control group. No differences were found between PAF patients with the controls in exercise time (10.38 +/- 2.93 vs 10.81 +/- 2.75 minutes); METs (6.98 +/- 1.72 vs 7.28 +/- 1.75 minutes); resting heart rate (79.13 +/- 14.86 vs 79.69 +/- 10.43 bpm); peak heart rate (146.83 +/- 23.21 vs 146.94 +/- 16.13 bpm). Maximum exercise P wave duration and P wave dispersion were greater than the rest measurements in PAF group (respectively P < 0.0001 and P = 0.0004). In PAF patients, P wave dispersion is significantly longer at rest, maximum exercise and recovery time than in a control group without PAF.

Increases in P-Wave Dispersion Predict Postoperative Atrial Fibrillation After Coronary Artery Bypass Graft Surgery

Article

Feb 2004
ANESTH ANALG

Unlabelled: Atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. In this study we examined the effect of surgery on atrial electrophysiology as measured by P-wave characteristics and to determine the potential predictive value of P-wave characteristics on the incidences of postoperative AF in patients undergoing CABG surgery. Patients undergoing elective CABG surgery were monitored by continuous electrocardiogram (ECG) telemetry during the in-hospital period until discharge for the occurrence of postoperative AF. Differences in P-wave characteristics (P-wave duration, amplitude, axis, dispersion, PR interval, segment depression, and dispersion) were compared between the pre- and postoperative 12-lead ECG measurements, and also between patients with and without postoperative AF. The association of postoperative AF and potential clinical predictors and P-wave characteristics were determined by multivariate logistic regression. Postoperative AF occurred in 81 (27%) of 300 patients. Univariate analysis showed that patients who subsequently developed postoperative AF compared with those without AF were significantly older (mean age 68 +/- 8 versus 63 +/- 10 yr, P < 0.0001), had a larger body surface area (BSA) (2.03 +/- 0.24 versus 1.92 +/- 0.22 m(2), P = 0.0002), were more likely to have a history of AF (8 of 81 versus 1 of 219, P = 0.003), used preoperative antiarrhythmic medications more frequently (7 of 81 versus 4 of 219, P = 0.01), and had a more frequent rate of return to the operating room for postoperative complications (9 of 81 versus 9 of 219, P = 0.029). Furthermore, the postoperative P-wave duration decreased to a larger extent (mean change -11.3 +/- 0.1 ms versus -8.4 +/- 0.1 ms, P < 0.0001), and the P-wave dispersion increased postoperatively to a larger extent (3.1 +/- 15.5 ms versus -1.6 +/- 14.6 ms, P = 0.028) in those who subsequently developed AF compared with those without AF. Multivariate logistic regression showed age (odds ratio [OR] = 1.1, 95% confidence interval [CI]: 1.06-1.15, P < 0.0001), BSA (OR = 38.1, 95% CI: 8.2-176, P < 0.0001), and an increase in postoperative P-wave dispersion (OR = 1.03, 95% CI: 1.01-1.05, P = 0.01) to be independent predictors of postoperative AF. No surgical factor was identified to be responsible for this postoperative change in atrial electrophysiology. Implications: In addition to clinical factors, such as advanced age and body surface area, we demonstrated that electrophysiologic changes involving an increase in P-wave dispersion postoperatively independently predict atrial fibrillation after coronary artery bypass graft surgery.

P-wave dispersion for predicting maintenance of sinus rhythm after cardioversion of atrial fibrillation

Article

Feb 2004
AM J CARDIOL

P-wave measurements and left atrial function were investigated to predict the maintenance of sinus rhythm. after cardioversion of atrial fibrillation. Left atrial dimension <45 mm (p = 0.02) and P-wave dispersion <46 ms (p<0.001) were independent predictors of sinus rhythm maintenance, with a sensitivity of 89% and 96%, respectively. Duration of atrial fibrillation, maximum P-wave duration, and no spontaneous echocardiographic contrast were also univariate predictors. (C) 2004 by Excerpta Medica, Inc.

Epidemiological Approaches To Heart Disease: The Framingham Study

Article

P-Wave Indices, Distribution and Quality Control Assessment (from the Framingham Heart Study)

Abstract

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