Paolo Pieragnoli's scientific contributionswhile working at University of Florence, Florens, Tuscany, Italy and other institutions
- Abstract: The purpose of this study was to evaluate the wavelength index (WLI) at three atrial sites in a group of 23 patients with recurrent episodes of lone paroxysmal atrial fibrillation (LPAF) and a control group (n = 20). All patients underwent programmed atrial stimulation (paced cycle length = 600 ms) at high, medium, and low lateral right atrial wall. P wave duration, sinus cycle length, and corrected sinus node recovery time were not significantly different between the two study groups. WLI... Show More
- Abstract: Permanent cardiac pacing has experienced an increase in indications, applications and numerous worldwide implantations. This has happened thanks to a constant technological advancement in hardware, available pacing mode choices, and an increasingly sophisticated multiprogrammability.
- Abstract: Background. There are a variety of approaches to the prevention of atrial fibrillation (AF) with pacing. Aim of this study was to test the safety and feasibility of interatrial septum pacing at the posterior triangle of Koch for AF prevention and to exclude potential arrhythmic effects. Matherial and Methods.Interatrial septum pacing was performed in 34 patients (21 males, 13 females, mean age 69±12 years): 9 without a history and clinical evidence of atrial fibrillation (AF) (6 with sinus... Show More
- Abstract: For many years implantable devices for cardiac pacing applications have been developed with the main aim of treating AV block and sinus node dysfunction. With the introduction of rate-responsive pacing in 1983, different kinds of sensors have been developed, clinically validated and introduced into the clinical practice for driving rate adaptive pacemakers.
- Abstract: Objectives: The purpose of this study was to investigate if single lead interatrial septum pacing could be effective in maintaining sinus rhythm in patients in whom restoration of sinus rhythm was only possible for a period of 2–24 hours after one or more previous electrical cardioversions, and in whom a sinus bradycardia was documented before arrhythmia restarted. The two hours limit was chosen because it was considered a sufficient time to implant a dual chamber pacemaker. Background:... Show More
- Abstract: PADELETTI, et al.: Atrioventricular Interval Optimization in the Right Atrial Appendage and Interatrial Septum Pacing: A Comparison Between ECHC and Peak Endocardial Acceleration. Interatrial septum pacing (IASP) reduces interatrial conduction time and consequently may interfere with atrioventricular delay (AVD) optimization. We studied 14 patients with an implanted BEST Living system device able to measure peak endocardial acceleration (PEA) signal. The aims of our study were to compare the... Show More
- Abstract: Aim of this study was to investigate the spatial patterns of organization of fibrillation in the right atrium using bipolar recordings from a basket catheter. Study population consists of 17 patients with persistent atrial fibrillation (AF), selected a priori for low energy internal cardioversion. Organization was measured by the number of occurrences--i.e. the percentage number of points laying on the baseline--which has been demonstrated to match Wells' criteria for the classification of... Show More
- Abstract: Background Inter-atrial septum pacing may prevent initiation or persistence of atrial fibrillation through suppression of premature beats and regularization of atrial rhythm; prolongation of the coupling interval of the premature beats in the abnormal substrate; and modification of the electrophysiological properties of the substrate. The aim of the present study was to evaluate the rate of progression to permanent atrial fibrillation in patients paced at the inter-atrial septum. Method A... Show More
- Abstract: It has not so far been elucidated whether the autonomic nervous system plays a role in the pathogenesis of atrial fibrillation relapse after electrical cardioversion. In 40 consecutive patients with atrial fibrillation (22 males, 18 females, mean age 60 +/- 2 years) submitted to successful electrical cardioversion (external in 26 and low-energy internal in 14) we evaluated the heart rate variability (24-hour Holter recording) immediately after restoration of sinus rhythm in order to assess... Show More
- Abstract: The aim of this study was to investigate the spatial patterns of organization of fibrillation in the right atrium using bipolar recordings from a basket catheter in a population of 17 patients with persistent AF. The number of occurrences (NO) (i.e., the number of points laying on the baseline) was used as an objective measure of organization. This parameter significantly matches Wells' criteria for the classification of bipolar recordings during AF. The anatomic correspondence of the... Show More
- Abstract: New atrial pacing techniques and overdrive pacing algorithms have been introduced to prevent atrial fibrillation. This study was designed to test the hypotheses that (1) interatrial septum pacing (IASP) at the triangle of Koch would be more effective than right atrial appendage pacing (RAAP) in preventing paroxysmal atrial fibrillation (PAF) in patients with sinus bradycardia and (2) an algorithm (CAP) designed to achieve constant atrial capture would increase the efficacy of rate-responsive... Show More
- Abstract: Optimal management of atrial arrhythmias with dual chamber pacemakers requires proper performance of automatic mode switching (AMS). The aim of this study was to develop a reliable technique to test the AMS function by using an external electronic device capable of mimicking the occurrence of supraventricular arrhythmias (Supraventricular Arrhythmia Simulator [SAS]). The SAS delivers low voltage pulse trains (200 mV, 20 ms) through two skin electrodes. Each pulse train lasts 15 seconds and... Show More
- Abstract: Biventricular pacing (BVP) can improve haemodynamics in patients with dilated cardiomyopathy (DCM) and left bundle branch block by reducing interventricular delay (IVD). Since in DCM interatrial delay (IAD) and IVD frequently coexist, the aim of this study was to test the hypothesis that IVD reduction associated with IAD produces an imbalance between the programmed right atrioventricular (AV) delay and the effective AV delay on the left, and that interatrial septum pacing (IASP) combined... Show More
- Abstract: Diagnostic (mapping) and therapeutic (ablation, pacing) advances have provided insight into atrial depolarization processes and new developments in P wave analysis. Information about interatrial pathways is important to the understanding of interatrial conduction delay. A standardized method for P wave analysis is necessary for the development of a clinical role for management of patients with paroxysmal atrial fibrillation using signal-averaged P wave analysis and P wave dispersion.... Show More
- Abstract: Surface electrocardiogram is commonly used to evaluate the normal and abnormal activation of the atria. Interatrial conduction appears as the most important factor determining P wave duration and morphology during sinus rhythm. A good estimation of the interatrial conduction time can be obtained by a simple esophageal recording or by P wave duration on the surface electrocardiogram. A careful analysis of the ectopic atrial beats on the 12-lead electrocardiogram can identify the site of... Show More
- Abstract: Closed-loop stimulation (CLS) is a physiological system for adaptive rate pacing based on monitoring and processing of the intracardiac impedance. The "standard" CLS algorithm (SCLS) requires continuous ventricular pacing. A new, enhanced CLS algorithm (ECLS) provides rate modulation during sensed and paced ventricular depolarizations. The aim of this study was to validate ECLS and to compare its effectiveness with that of SCLS. Ten patients received Inos2+ CLS pulse generators. SCLS and... Show More
Publications citing this author (1225)
[Show abstract] [Hide abstract] ABSTRACT: Heart failure(HF) and atrial fibrillation(AF) frequently coexist in the same patient and are associated with increased mortality and frequent hospitalizations. As the concomitance of AF and HF is often associated with a poor prognosis, the prompt treatment of AF in HF patients may significantly improve outcome. Recent implantable cardiac resynchronization (CRT) devices allow electrical therapies to treat AF automatically. TRADE-HF (trial registration: NCT00345592; http://www.clinicaltrials.gov) is a prospective, randomized, double arm study aimed at demonstrating the efficacy of an automatic, device-based therapy for treatment of atrial tachycardia and fibrillation(AT/AF) in patients indicated for CRT. The study compares automatic electrical therapy to a traditional more usual treatment of AT/AF: the goal is to demonstrate a reduction in a combined endpoint of unplanned hospitalizations for cardiac reasons, death from cardiovascular causes or permanent AF when using automatic atrial therapy as compared to the traditional approach involving hospitalization for symptoms and in-hospital treatment of AT/AF. CRT pacemaker with the additional ability to convert AF as well as ventricular arrhythmias may play a simultaneous role in rhythm control and HF treatment. The value of the systematic implantation of CRT ICDs with the capacity to deliver atrial therapy in HF patients at risk of AF has not yet been explored. The TRADE-HF study will assess in CRT patients whether a strategy based on automatic management of atrial arrhythmias might be a valuable option to reduce the number of hospital admission and to reduce the progression the arrhythmia to a permanent form. NCT00345592.
- Despite this study is not powered to explore this potential specific clinical benefit, any differences observed in the component of the primary endpoints or in secondary endpoints (i.e permanent AF or cardiac cause hospitalizations) could be useful to generate further hypotheses on this topic. Early treatment of AF also seems to be justified as far as histopathology is concerned, as arrhythmia is not only an electrical pathology, but a condition that, over an extended time, may induce non-reversible organic diseases such as fibrosis and conduction abnormalities34353637. In light of this, early AF treatment could be reserved even for those patients with a lower AF burden or for those with no history of AF.
[Show abstract] [Hide abstract] ABSTRACT: PurposeLeft ventricular (LV) torsion is an important parameter of LV performance and can be influenced by several factors. Aim of this investigation was to evaluate whether QRS prolongation in left bundle branch block (LBBB) may influence global LV twist and twisting/untwisting rate in chronic systolic heart failure (HF) patients.Methods We prospectively evaluated 30 healthy subjects (control group) and 100 chronic HF patients with severely impaired LV systolic function (ejection fraction ≤35%). Patients were divided into three groups according to QRS duration: A: QRS < 120 ms (n 49), B: 120 ≤ QRS ≤ 150 ms (n 28) and C: QRS > 150 ms (n 23). Patients in groups B and C presented LBBB. All subjects underwent standard trans-thoracic echocardiography and two-dimensional speckle-tracking echocardiography evaluation. Categorical variables were compared by the chi-square or the Fisher's exact test. Continuous variables were compared using the ANOVA test. Correlations between variables were analysed with linear regression.ResultsControl subjects presented higher torsion parameters, when compared with patients in any HF group. Among the three HF groups, no differences were detected in global twist (4·79 ± 3·54, 3·8 ± 3·0 and 4·15 ± 3·14 degrees, respectively), twist rate max (44·81 ± 25·03, 37·94 ± 19·09 and 37·61 ± 24·49 degrees s−1, respectively) and untwist rate max (−36·31 ± 30·89, −27·68 ± 34·67 and −39·62 ± 26·27 degrees s−1, respectively) (P>0·05 for all). At linear regression analysis, there was no relation between QRS duration and any torsion parameter (P>0·05 for all).Conclusions In patients with chronic severe systolic heart failure, QRS duration and LBBB morphology do not affect LV twisting and untwisting.
- Moreover, LBBB is also an expression of LV dyssynchrony , as the alteration in LV electrical activation usually begets altered LV mechanical activity (Grines et al., 1989; Nelson et al., 2000). However, in about one-third of patients, LV mechanical dyssynchrony can be absent, despite the presence of electrical delay (Bleeker et al., 2004; Porciani et al., 2010). Recently, LBBB was supposed to play a pivotal role in inducing the onset of LV dysfunction, and not merely to be a sign of its presence (Breithardt & Breithardt, 2012).
[Show abstract] [Hide abstract] ABSTRACT: Abstract Aims: Cardiac autonomic modulation (CAM) may be pivotal for atrial fibrillation (AF) occurrence and affect early recurrence (ER) after electrical cardioversion (EC). Previous studies investigating linear (L) heart rate variability (HRV) after EC have given conflicting results about which CAM pattern favours ER. This study aimed at evaluating if non-linear (NL) HRV analysis (HRVa) could provide better accuracy in predicting ER. Methods: 36 patients, 16 under antiarrhythmic drugs (AAD), were enrolled after EC for persistent AF. Stable sinus rhythm (SR) was obtained in 34. HRVa was performed, with L and NL methods, from five-minutes time-segments selected within the first hour after EC and the subsequent 24 (daily activity and sleep). Discriminant Analysis (DA) was used to evaluate which parameters were efficient in predicting ER of AF. Results: When comparing 14/34 patients with AF ER (Group1) with twenty who maintained SR (Group2), no significant difference were found immediately after EC and during daily activity. However, sympathetic prevalence was found in Group1 during sleep. At DA, only NL SampEn predicted AF ER (accuracy: 73.5%). In 18 patients without AAD pre-treatment, higher sympathetic modulation during daily activity and vagal prevalence during sleep were found in patients without AF ER (p<0.05). DA during sleep predicted AF recurrence with 83.3% and 100% accuracy when using L and NL parameters, respectively. Conclusions: During the first 24 hours after EC, CAM is different in patients with and without AF ER. NL HRVa exploring the complexity of CAM of HRV predicts AF ER with better accuracy.
- Substantial prevalence of sympathetic modulation and lower HRV complexity during sleep (higher SDNN/RMSSD ratio, lower HF power, higher LF power and higher LF/HF ratio, lower values of ApEn and SampEn, lower SD1/SD2 ratio) were confirmed as significant markers of risk for ER of AF (Table 3). Thus unbalance of cardiac autonomic modulation favoring sympathetic prevalence (and depression of vagal tone) during night sleep may predispose to AF recurrence[4,49]. Instead, in Group 1a patients early AF recurrence was correlated with a tendency of prevalent vagal modulation during daily activity, evidenced by lower SDNN/RMSSD ratio, higher HF component, lower LF component and lower LF/HF ratio, which however did not reach statistical significance.
[Show abstract] [Hide abstract] ABSTRACT: BACKGROUND The aim of our study was to investigate the P-wave dispersion from standard electrocardiograms (ECGs) in patients with acute myocardial infarction (AMI) after cardiac rehabilitation (CR) and determine its relation to arterial stiffness. METHODS This is a prospective study included 33 patients with AMI and successfully re-vascularized by percutaneous coronary intervention (PCI) underwent CR. Left ventricular ejection fraction (LVEF) was measured by biplane Simpson’s method. Left atrium (LA) volume was calculated. The maximum and minimum durations of P-waves (Pmax and Pmin, respectively) were detected, and the difference between Pmax and Pmin was defined as P-wave dispersion (Pd = Pmax-Pmin). Aortic elasticity parameters were measured. RESULTS LVEF was better after CR. The systolic and diastolic blood pressures decreased after CR, these differences were statistically significant. With exercise training, LA volume decreased significantly. Pmax and Pd values were significantly shorter after the CR program. The maximum and minimum P-waves and P-wave dispersion after CR were 97 ± 6 ms, 53 ± 5 ms, and 44 ± 5 ms, respectively. Aortic strain and distensibility increased and aortic stiffness index was decreased significantly. Aortic stiffness index was 0.4 ± 0.2 versus 0.3 ± 0.2, P = 0.001. Aortic stiffness and left atrial volume showed a moderate positive correlation with P-wave dispersion (r = 0.52, P = 0.005; r = 0.64, P < 0.001, respectively). CONCLUSION This study showed decreased arterial stiffness indexes in AMI patient’s participated CR, with a significant relationship between the electromechanical properties of the LA that may raise a question of the preventive effect of CR from atrial fibrillation and stroke in patients with acute myocardial infarction.
- The prolongation of electromechanical delay (EMD) and the inhomogeneous propagation of sinus impulses are well-known electrophysiological characteristics of the atria prone to fibrillation.7 IACT can be measured by two-dimensional (2D)-Doppler echocardiography, including tissue Doppler imaging. IACT measured by 2D-Doppler echocardiography and its association with indices of LA function has been reported in a few studies in patients with left ventricular (LV) systolic dysfunction.8-11 Deniz et al. compared the tissue Doppler echocardiography and electrophysiological study in the measurement of atrial conduction times and found a moderate correlation between intra-left atrial conduction time by echocardiography (ILCT-echo) and ILCT by electrophysiology (ILCT-eps), which means that tissue Doppler echocardiography can be used to evaluate atrial conduction time.12
[Show abstract] [Hide abstract] ABSTRACT: Dual sensor (DS) for rate adaption was supposed to be more physiological. To evaluate its superiority, the DS (accelerometer [ACC] and minute ventilation [MV]) and normal sinus rate response were compared in a self-controlled way during exercise treadmill testing. This self-controlled study was performed in atrioventricular block patients with normal sinus function who met the indications of pacemaker implant. Twenty-one patients came to the 1-month follow-up visit. Patients performed a treadmill test 1-month post implant while programmed in DDDR and sensor passive mode. For these patients, sensor response factors were left at default settings (ACC = 8, MV = 3) and sensor indicated rates (SIRs) for DS, ACC and MV sensor were retrieved from the pacemaker memories, along with measured sinus node (SN) rates from the beginning to 1-minute after the end of the treadmill test, and compared among study groups. Repeated measures analysis of variance and profile analysis, as well as variance analysis of randomized block designs, were used for statistical analysis. Fifteen patients (15/21) were determined to be chronotropically competent. The mean differences between DS SIRs and intrinsic sinus rates during treadmill testing were smaller than those for ACC and MV sensor (mean difference between SIR and SN rate: ACC vs. SN, MV vs. SN, DS vs. SN, respectively, 34.84, 17.60, 16.15 beats/min), though no sensors could mimic sinus rates under the default settings for sensor response factor (ACC vs. SN P-adjusted < 0.001; MV vs. SN P-adjusted = 0.002; DS vs. SN P-adjusted = 0.005). However, both in the range of 1 st minute and first 3 minutes of exercise, only the DS SIR profile did not differ from sinus rates (P-adjusted = 0.09, 0.90, respectively). The DS under default settings provides more physiological rate response during physical activity than the corresponding single sensors (ACC or MV sensor). Further study is needed to determine if individual optimization would further improve adaptive performance of the DS.
-  While the potential benefits of rate adaptive pacing do not prove significant in the general pacemaker population, superiority is observed in a selected patient population, especially for the DS‑driven pacemakers. [21,24] Our study participants were younger than those reported in the studies mentioned above, and their average and peak sinus rates reflected a need for higher heart rate support. Therefore, it is unknown whether DS devices might stand out for the relative young and physically active patient population with marked chronotropic incompetence.
- Although this technique seems to be less aggressive, its benefit appears smaller. Other authors [43, 44] use His-bundle pacing, which may be effective in patients with non-wide QRS, and may induce a greater QRS narrowing, although this is not always accompanied by an improvement in LV function. Few studies  describe Purkinje fiber pacing, which is similar to conventional pacing, and may be useful in patients with ischemic heart disease, with more stable stimulation in cases of myocardial damage.
[Show abstract] [Hide abstract] ABSTRACT: Background. Patients treated for sick sinus syndrome may have interatrial conduction disorder leading to atrial fibrillation. Objectives. This study was aimed to assess the influence of the atrial pacing site on interatrial and atrioventricular conduction as well as the percentage of ventricular pacing in patients with sick sinus syndrome implanted with atrioventricular pacemaker. Material and Methods. The study population: 96 patients (58 females, 38 males) aged 74.1 ± 11.8 years were divided in two groups: Group 1 (n = 44) with right atrial appendage pacing and group 2 (n = 52) with Bachmann's area pacing. We assessed the differences in atrioventricular conduction in sinus rhythm and atrial 60 and 90 bpm pacing, P-wave duration and percentage of ventricular pacing. Results. No differences in baseline P-wave duration in sinus rhythm between the groups (102.4 ± 17 ms vs. 104.1 ± 26 ms, p = ns.) were noted. Atrial pacing 60 bpm resulted in longer P-wave in group 1 vs. group 2 (138.3 ± 21 vs. 106.1 ± 15 ms, p < 0.01). The differences between atrioventricular conduction time during sinus rhythm and atrial pacing at 60 and 90 bpm were significantly longer in patients with right atrial appendage vs. Bachmann's pacing (44.1 ± 17 vs. 9.2 ± 7 ms p < 0.01 and 69.2 ± 31 vs. 21.4 ± 12 ms p < 0.05, respectively). The percentage of ventricular pacing was higher in group 1 (21 vs. 4%, p < 0.01). Conclusions. Bachmann's bundle pacing decreases interatrial and atrioventricular conduction delay. Moreover, the frequency-dependent atrioventricular conduction lengthening is much less pronounced during Bachmann's bundle pacing. Right atrial appendage pacing in sick sinus syndrome patients promotes a higher percentage of ventricular pacing.
- ers to be the best pacing placement with regards to the activation time of both atria, which seems to be in line with the theoretical model [16, 17]. In some studies this kind of atrial pacing was also combined with paroxysmal atrial fibrillation pre? vention [18, 19]. The most important factor influ? encing the study results and the clinical effect in a particular population was the interatrial conduc?
[Show abstract] [Hide abstract] ABSTRACT: Background: Arrhythmias are frequent in Systemic Sclerosis (SSc) and portend a bad prognosis, accounting alone for 6% of total deaths. Many of these patients die suddenly, thus prevention and intensified risk-stratification represent unmet medical needs. The major goal of this study was the definition of ECG indexes of poor prognosis. Methods: We performed a prospective cohort study to define the role of 24h-ECG-Holter as an additional risk-stratification technique in the identification of SSc-patients at high risk of life-threatening arrhythmias and sudden cardiac death (SCD). One-hundred SSc-patients with symptoms and/or signs suggestive of cardiac involvement underwent 24h-ECG-Holter. The primary end-point was a composite of SCD or need for implantable cardioverter defibrillator (ICD). Results: Fifty-six patients (56%) had 24h-ECG-Holter abnormalities and 24(24%) presented frequent ventricular ectopic beats (VEBs). The number of VEBs correlated with high-sensitive cardiac troponin T (hs-cTnT) levels and inversely correlated with left-ventricular ejection fraction (LV-EF) on echocardiography. During a mean follow-up of 23.1±16.0 months, 5 patients died suddenly and two required ICD-implantation. The 7 patients who met the composite end-point had a higher number of VEBs, higher levels of hs-cTnT and NT-proBNP and lower LV-EF (p = 0.001 for all correlations). All these 7 patients had frequent VEBs, while LV-EF was not reduced in all and its range was wide. At ROC curve, VEBs>1190/24h showed 100% of sensitivity and 83% of specificity to predict the primary end-point (AUROC = 0.92,p<0.0001). Patients with VEBS>1190/24h had lower LV-EF and higher hs-cTnT levels and, at multivariate analysis, the presence of increased hs-cTnT and of right bundle branch block on ECG emerged as independent predictors of VEBs>1190/24h. None of demographic or disease-related characteristics emerged as predictors of poor outcome. Conclusions: VEBS>1190/24h identify patients at high risk of life-threatening arrhythmic complications. Thus, 24h-ECG-Holter should be considered a useful additional risk-stratification test to select SSc-patients at high-risk of SCD, in whom an ICD-implantation could represent a potential life-saving intervention.
- In this scenario, a number of VEBs>1190/24h appears to have an excellent positive predictive value in the identification of patients at high risk of SCD and therefore eventually candidates for an ICD implantation. In a recent study an ICD was implanted in 10 SSc patients with cardiac involvement and ventricular arrhythmias on 24h ECG-Holter, and analysis of devices after 36 months revealed several episodes of VT in 3 patients (all with a number of VEBs>5000/24h at baseline ECG-Holter), which were promptly reverted by electrical shock delivery, underlying again the prognostic importance of Holter abnormalities  and the clinical significance of primary prevention of SCD in selected SSc populations. Currently, guidelines for the management of cardiac arrhythmias and for the use of ICD to prevent SCD mainly target patients who have already survived a SCD or a life-threatening arrhythmic event, or those with a severe underlying heart disease; thus, it's primarily a secondary prevention.
[Show abstract] [Hide abstract] ABSTRACT: The SonR signal has been shown to reflect cardiac contractility. It is recorded with an atrial lead connected to a cardiac resynchronization therapy defibrillator. For the first time, clinical evidence on the use of the SonR signal in the monitoring of the clinical status of heart failure patients implanted with cardiac resynchronization therapy defibrillator are presented through three clinical cases. In the two first patients (non-Hispanic/Latino white), the SonR amplitude increases concomitantly to clinical status improvement subsequent to cardiac resynchronization therapy defibrillator implantation. In the third patient (non-Hispanic/Latino white), a decrease in SonR amplitude is observed concomitantly to atrial fibrillation and clinical status deterioration. This case series reports the association between SonR signal amplitude changes and patients' clinical status. Combined with remote monitoring, early SonR signal amplitude remote monitoring could be a promising tool for heart failure patients' management.
- The SonR signal is monitored and computerized by the embedded SonR algorithm through an implantable system consisting of an atrial pacing lead (SonRTip™ lead, Sorin CRM, Clamart, France) connected to a cardiac resynchronization therapy defibrillator (CRT-D) device. Additionally , SonR allows automatic weekly atrioventricular (AV) and interventricular (VV) delays optimization in heart failure (HF) CRT-D patients, at rest and exercise6789. The three following clinical cases report information on recipients of Paradym RF™ SonR CRT-D (Sorin CRM SAS, Clamart, France), implanted for HF with either ischemic (ICM) or dilated cardiomyopathy (DCM).
[Show abstract] [Hide abstract] ABSTRACT: ECG markers derived from the P-wave are used frequently to assess atrial function and anatomy, e.g. left atrial enlargement. While having the advantage of being routinely acquired, the processes underlying the genesis of the P-wave are not understood in their entirety. Particularly the distinct contributions of the two atria have not been analyzed mechanistically. We used an in silico approach to simulate P-waves originating from the left atrium (LA) and the right atrium (RA) separately in two realistic models. LA contribution to the P-wave integral was limited to 30 % or less. Around 20 % could be attributed to the first third of the P-wave which reflected almost only RA depolarization. Both atria contributed to the second and last third with RA contribution being about twice as large as LA contribution. Our results foster the comprehension of the difficulties related to ECG-based LA assessment.
- However, despite a multitude of empirical studies relating P-wave features to left and right atrial influences [1,3,11], we are still lacking mechanistic understanding of left and right atrial contribution to the P-wave. While some sources state that the peaks corresponding to left and right atrial excitation are normally almost simultaneous, thus fused into a single peak  , others argue that the second half of the P-wave mainly corresponds to left atrial depolarization . Insight into the question which ECG leads reflect the depolarization of which parts of the atria during the different temporal phases of the P-wave may eventually help to identify patients at risk to develop AF, thus relieving part of the burden from patients and healthcare.
[Show abstract] [Hide abstract] ABSTRACT: The right atrial appendage (RAA) and right ventricular apex (RVA) have been widely considered as conventional sites for typical dual-chamber atrio-ventricular cardiac (DDD) pacing. Unfortunately conventional RAA pacing seems not to be able to prevent atrial fibrillation in DDD pacing for tachycardia-bradycardia syndrome, and the presence of a left bundle branch type of activation induced by RVA pacing can have negative effects. A new technology with active screw-in leads permits a more physiological atrial and right ventricular pacing. In this review, we highlight the positive effects of pacing of these new and easily selected sites. The septal atrial lead permits a shorter and more homogeneous atrial activation, allowing better prevention of paroxysmal atrial fibrillation. The para-Hisian pacing can be achieved in a simpler and more reliable way with respect to biventricular pacing and direct Hisian pacing. We await larger trials to consider this "easy and physiological pacing" as a first approach in patients who need a high frequency of pacing.
- The main benefits that these sites should provide are: (1) a very short interatrial conduction delay and a significant decrease in P-wave duration; (2) a reduction in dispersion of atrial refractoriness; (3) a more homogeneous recovery of excitability and atrial activation; and (4) electrical atrial remodeling, with a gradual reduction in left atrial diameters and volume. Data on the two lead techniques (dual site atrial pacing or biatrial pacing) are still controversial192021 . In contrast , the single lead interatrial septum pacing seems to be easier, and more effective and feasible, compared with conventional RAA pacing, providing significant benefits in preventing paroxysmal atrial fibrillation and decreasing the progression to chronic atrial fibrillation [18,22] .
[Show abstract] [Hide abstract] ABSTRACT: Sudden cardiac death remains a major cause of mortality in patients with heart failure, and accounts for almost 50% of all sudden deaths occurring in this patient population. The rate and and causes of sudden death depend on the type of heart disease and the severity of heart failure. Heart failure with preserved systolic function covers a huge heterogeneous group of patients with congenital and acquired heart disease, hypertrophic and restrictive cardiomyopathy, and also includes the concept of endomyocardial fibrosis. Low ejection fraction of the left ventricle, its dilatation, as well as high blood level of NT-proBNP are the main predictors of SCD. Factors predisposing to the overall mortality or death rates due to insufficient contractile function of the heart are not necessarily related to an increased risk of sudden death. Changing management of heart failure also complicates the design of a simple prediction algorithm. Beta-blockers, for example, have a more significant impact on myocardial remodeling than on exercise tolerance, so the role of the independent predictors of patients may vary depending on the presence of the therapeutic regimen in this group of drugs. There are lots of drugs that can reduce the risk of sudden cardiac death in patients with heart failure. The main achievement of the past 20 years is the ability to inhibit the chronic hyperactivity of neurohormones by medications thus slowing down the development of changes in target organs, preventing the progression of heart failure, and to reduce electrical remodeling, thus preventing arrhythmias. Nowadays implantation of cardioverterdefibrillators is the most effective approach to prevent SCD and results in reduction in total mortality in patients with heart failure. The functional class of heart failure, as well as the etiology of the disease are the main points in deciding whether to implant a cardioverter-defibrillator. Many randomized trials showed that ICD therapy was associated with reduction in mortality not only from SCD but also from all other causes compared to traditional antiarrhythmic drugs. Evolving technology increases the effectiveness of treatment and reduces the number of complications and the risk of SCD. The research area devoted to the prevention of sudden cardiac death is certainly the most relevant in the modern cardiology. Ongoing clinical studies will optimize methods and solve present problems.
- Имеются данные об улучшении показателей вариабельности сердечного ритма на фоне бивентрикулярной стимуляции, что приводит к снижению риска ВСС. Показано положительное влияние длительной бивентрикулярной стимуляции на ремоделирование, систолическую и диастолическую дисфункции ЛЖ  . В нескольких работах была выявлена зависимость обратного ремоделирования миокарда от уменьшения его асинхронизма .
[Show abstract] [Hide abstract] ABSTRACT: A 47-year-old female with a dual chamber pacemaker was referred to our institution for transvenous lead removal because of suspected pocket infection.
- Physiologically, the electrical excitation radiates from the endocardium to the epicardium. Therefore, arrhythmias with an epicardial origin have a higher risk regarding the development of ventricular fibrillation or torsades [6,7]. If you pace the left ventricle from epicardium only, you must be aware of this fact.
[Show abstract] [Hide abstract] ABSTRACT: Biventricular (Biv) pacemaker echo optimization has been shown to improve cardiac output however is not routinely used due to its complexity. We investigated the role of a simple method involving computerized pre-ejection time (PEP) assessment by radial artery tonometry in guiding Biv pacemaker optimization. Blinded echo and radial artery tonometry were performed simultaneously in 37 patients, age 69.1 ± 12.8 years, left ventricular (LV) ejection fraction (EF) 33 ± 10%, during Biv pacemaker optimization. Effect of optimization on echo derived velocity time integral (VTI), ejection time (ET), myocardial performance index (MPI), radial artery tonometry derived PEP and echo-radial artery tonometry derived PEP/VTI and PEP/ET indices was evaluated. Significant improvement post optimization was achieved in LV ET (286.9 ± 37.3 to 299 ± 34.6 ms, p < 0.001), LV VTI (15.9 ± 4.8 cm to 18.4 ± 5.1 cm, p < 0.001) and MPI (0.57 ± 0.2 to 0.45 ± 0.13, p < 0.001) and in PEP (246.7 ± 36.1 ms to 234.7 ± 35.5 ms, p = 0.003), PEP/ET (0.88 ± 0.21 to 0.79 ± 0.17, p < 0.001), and PEP/VTI (17.3 ± 7 to 13.78 ± 4.7, p < 0.001). The correlation between comprehensive echo Doppler and radial artery tonometry-PEP guided optimal atrioventricular delay (AVD) and optimal interventricular delay (VVD) was 0.75 (p < 0.001) and 0.69 (p < 0.001) respectively. In 29 patients with follow up assessment, New York Heart Association (NYHA) class reduced from 2.5 ± 0.8 to 2.0 ± 0.9 (p = 0.004) at 1.8 ± 1.4 months. An acute shortening of PEP by radial artery tonometry occurs post Biv pacemaker optimization and correlates with improvement in hemodynamics by echo Doppler and may provide a cost-efficient approach to assist with Biv pacemaker echo optimization.
- Cardiac resynchronization therapy (CRT) also referred to as atrial-synchronous biventricular (Biv) pacing, has been an effective treatment for medically refractory HF patients with ventricular dyssynchrony [1,6]. It is able to shorten PEP, lengthen ET and reduce MPI thus leading to an increase in LV effective fraction and stoke volume [6,7]., Thus PEP, ET and MPI have been regarded as the primary parameters to guide pacemaker optimization [8,9]. Maximum hemodynamic improvement occurs at an AV delay (AVD) that provides the most favorable preload and an interventricular delay (VVD) that exhibits 1 Non Invasive Diagnostic Services and Echocardiography Laboratory, Cardiovascular and Thoracic Institute, Keck School of Medicine, University of Southern California, Los Angeles, USA Full list of author information is available at the end of the article Taha et al.
[Show abstract] [Hide abstract] ABSTRACT: Background The contribution of right ventricular (RV) stimulation to cardiac resynchronisation therapy (CRT) remains controversial. RV stimulation might be associated with adverse haemodynamic effects, dependent on intrinsic right bundle branch conduction, presence of scar, RV function and other factors which may partly explain non-response to CRT. This study investigates to what degree RV stimulation modulates response to biventricular (BiV) stimulation in CRT candidates and which baseline factors, assessed by cardiac magnetic resonance imaging, determine this modulation. Methods and results Forty-one patients (24 (59 %) males, 67 ± 10 years, QRS 153 ± 22 ms, 21 (51 %) ischaemic cardiomyopathy, left ventricular (LV) ejection fraction 25 ± 7 %), who successfully underwent temporary stimulation with pacing leads in the RV apex (RVapex) and left ventricular posterolateral (PL) wall were included. Stroke work, assessed by a conductance catheter, was used to assess acute haemodynamic response during baseline conditions and RVapex, PL (LV) and PL+RVapex (BiV) stimulation. Compared with baseline, stroke work improved similarly during LV and BiV stimulation (∆+ 51 ± 42 % and ∆+ 48 ± 47 %, both p < 0.001), but individual response showed substantial differences between LV and BiV stimulation. Multivariate analysis revealed that RV ejection fraction (β = 1.01, p = 0.02) was an independent predictor for stroke work response during LV stimulation, but not for BiV stimulation. Other parameters, including atrioventricular delay and scar presence and localisation, did not predict stroke work response in CRT. Conclusion The haemodynamic effect of addition of RVapex stimulation to LV stimulation differs widely among patients receiving CRT. Poor RV function is associated with poor response to LV but not BiV stimulation.
- Ischemic (n/y) 7.48 0.45 − 13.53 0.31 5.61 0.71 15.80 0.07 Stringent LBBB (n/y) 10.44 0.34 21.51 0.13 10.39 0.51 − 5.72 0. Left bundle branch block (LBBB), stringent LBBB according to Strauss criteria (see Methods), PL posterolateral, RVEDV right ventricular enddiastolic volume, RVESV right ventricular end-systolic volume, RVEF right ventricular ejection fraction, LVEDV left ventricular end-diastolic volume, LVESV left ventricular end-systolic volume, LVEF left ventricular ejection fraction, LVSW left ventricular stroke work, LVdP/dt max left ventricular dP/dt max , RV apex , right ventricular apex, LV left ventricular, BiV biventricular. but the size of this interrelation is generally assumed to be small and contradictory results have been reported [21, 25]. On the other hand, we observed substantial effects of RV a- pex stimulation on LV stroke work response.
University of Florence
Florens, Tuscany, Italy
- Dipartimento di Chirurgia e Medicina Traslazionale (DCMT)