Increased ventricular ectopic activity and even more complex arrhythmias are not uncommon in subjects without apparent heart disease. However, their prognostic significance has been controversial and not updated in recent years. The prevalence and prognostic significance of different ventricular arrhythmias were studied in a cohort of middle-aged and elderly subjects without apparent heart disease. Six hundred seventy-eight men and women aged 55 to 75 years without a history of heart disease or stroke were included. Baseline examinations included physical examinations, fasting laboratory testing, and 48-hour ambulatory electrocardiographic monitoring. All patients were followed for up to 5 years. Combined events were defined as all-cause mortality or acute myocardial infarction. A cardiovascular event was defined as cardiovascular death or acute myocardial infarction. In total, 84% had 0 to 10 ventricular premature complexes (VPCs)/hour, 8% had 11 to 30 VPCs/hour, and 8% had >30 VPCs/hour; 10.8% had >or=1 run of >or=3 VPCs. Frequent VPCs (>or=30/hour) was a significant predictor of combined (hazard ratio 2.47, 95% confidence interval 1.29 to 4.68, p = 0.006) and cardiovascular (hazard ratio 2.85, 95% confidence interval 1.16 to 7.0, p = 0.023) event rates, after adjustment for conventional risk factors. Runs of >or=4 VPCs/day or >or=2 doublets/day were also associated with a poor prognosis, but only in the presence of frequent VPCs. The detection of a single VPC on standard electrocardiography was a significant predictor of frequent VPCs and an independent predictor of events (hazard ratio 2.6, 95% confidence interval 1.02 to 6.66, p = 0.045). In conclusion, apparently healthy, middle-aged and elderly subjects with frequent VPCs (>or=30/hour) have a poor prognosis. According to current guidelines, strict risk-factor modification and primary prevention are justified in these high-risk subjects.
"Consistent cut-offs for the number or complexity (multiforms, pairs, runs, R-on-T) of PVC per unit time of Holter recording associated with mortality risk across population groups of different ages, ethnicities or underlying cardiovascular risk have yet to be established [3-6]. Thus, a main limitation of this work is the uncertain prognostic significance of PVC endpoints selected in this high-risk population, which can be determined through long term follow-up for incidence of ventricular fibrillation, tachycardia, sudden cardiac death, or CVD mortality. "
[Show abstract][Hide abstract] ABSTRACT: Premature ventricular complexes (PVC) predict cardiovascular mortality among several adult populations. Increased arrhythmia prevalence has been reported during controlled magnesium (Mg) depletion studies in adults. We thus hypothesized that serum magnesium (sMg) concentrations are inversely associated with the prevalence of PVC in adults at high cardiovascular risk.
Anthropometric, demographic and lifestyle characteristics were assessed in 750 Cree adults, aged > 18 yrs, who participated in an age-stratified, cross-sectional health survey in Quebec, Canada. Holter electrocardiograms recorded heart rate variability and cardiac arrhythmias for two consecutive hours. Multivariate logistic regression was used to evaluate the associations between sMg and PVC.
PVC prevalence in adults with hypomagnesemia (sMg ≤ 0.70 mmol/L) was more than twice that of adults without hypomagnesemia (50% vs. 21%, p = 0.015); results were similar when adults with cardiovascular disease history were excluded. All hypomagnesemic adults with PVC had type 2 diabetes (T2DM). Prevalence of PVC declined across the sMg concentration gradient in adults with T2DM only (p < 0.001 for linear trend). In multivariate logistic regressions adjusted for age, sex, community, body mass index, smoking, physical activity, alcohol consumption, kidney disease, antihypertensive and cholesterol lowering drug use, and blood docosahexaenoic acid concentrations, the odds ratio of PVC among T2DM subjects with sMg > 0.70 mmol/L was 0.24 (95% CI: 0.06-0.98) p = 0.046 compared to those with sMg ≤ 0.70 mmol/L.
sMg concentrations were inversely associated with the prevalence of PVC in patients with T2DM in a dose response manner, indicating that suboptimal sMg may be a contributor to arrhythmias among patients with T2DM.
"Nowadays, CRT-D devices are capable of measuring a variety of parameters beyond heart rhythm and of transmitting measured values remotely to the physician.6–11 The following parameters may warn of impending ADHF or other cardiovascular events and predict poor clinical outcome: (i) sustained decrease in thoracic impedance due to lung fluid retention5–8,12–15 (measured between a lead in the right ventricle and the generator in the left pectoral region or using alternative current pathways);16–18 (ii) low heart rate variability, indicating sympathetic dominance in cardiac autonomic control;6,7,12,19–22 (iii) a high resting heart rate or relatively high mean heart rate over 24 h;6,19,21,23–25 (iv) decreased patient activity, potentially reflecting exercise intolerance;7,12,19–21 (v) increased frequency of ventricular extrasystoles;26 (vi) ventricular tachyarrhythmia episodes or defibrillation shocks;7,27,28 (vii) prolonged duration of atrial fibrillation;7,21,22 (viii) rapid ventricular rate during atrial fibrillation;7,21 (ix) reduced cardiac resynchronization pacing percentage, indicating a failure in the electrical treatment of cardiac asynchrony;7,29 (x) minute ventilation disturbances;30 and (xi) haemodynamic deterioration monitored with impedance-based or pressure sensors.8,16,18,31,32 Combining several of these parameters into a single algorithm may improve the overall ability to risk-stratify patients with implanted devices.7,33 "
[Show abstract][Hide abstract] ABSTRACT: To investigate whether diagnostic data from implanted cardiac resynchronization therapy defibrillators (CRT-Ds) retrieved automatically at 24 h intervals via a Home Monitoring function can enable dynamic prediction of cardiovascular hospitalization and death.
Three hundred and seventy-seven heart failure patients received CRT-Ds with Home Monitoring option. Data on all deaths and hospitalizations due to cardiovascular reasons and Home Monitoring data were collected prospectively during 1-year follow-up to develop a predictive algorithm with a predefined specificity of 99.5%. Seven parameters were included in the algorithm: mean heart rate over 24 h, heart rate at rest, patient activity, frequency of ventricular extrasystoles, atrial-atrial intervals (heart rate variability), right ventricular pacing impedance, and painless shock impedance. The algorithm was developed using a 25-day monitoring window ending 3 days before hospitalization or death. While the retrospective sensitivities of the individual parameters ranged from 23.6 to 50.0%, the combination of all parameters was 65.4% sensitive in detecting cardiovascular hospitalizations and deaths with 99.5% specificity (corresponding to 1.83 false-positive detections per patient-year of follow-up). The estimated relative risk of an event was 7.15-fold higher after a positive predictor finding than after a negative predictor finding.
We developed an automated algorithm for dynamic prediction of cardiovascular events in patients treated with CRT-D devices capable of daily transmission of their diagnostic data via Home Monitoring. This tool may increase patients' quality of life and reduce morbidity, mortality, and health economic burden, it now warrants prospective studies. ClinicalTrials.gov NCT00376116.
European Journal of Heart Failure 09/2011; 13(9):1019-27. DOI:10.1093/eurjhf/hfr089 · 6.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: During the past almost 50 years Holter monitoring has become an established non-invasive diagnostic tool in clinical electrophysiology.
It allows ECG recording independent of stationary monitoring facilities during daily life and, therefore, contains much information.
In the beginning the main interest was directed towards quantitative and qualitative assessment of arrhythmias, their circadian
behaviour, and the circadian behaviour of the heart rate. With advances in technology the analysis spectrum of Holter monitoring
expanded, and it was used also for detection of silent myocardial ischaemia. New digital recorders and computers with large
capacities made it possible to measure every single heart beat very accurately, which was a prerequisite for heart rate variability
and QT-interval analysis, which provided new knowledge about the autonomic modulation of the heart rate and the circadian
dynamicity of the QT interval, respectively. Beyond arrhythmia analysis Holter monitoring was increasingly used to assess
prognosis in different cardiac conditions. It can also be valuable in assessing transient symptoms possibly related to arrhythmias
or device dysfunction, which will not necessarily be revealed by simple device control.
In den vergangenen fast 50 Jahren hat sich das Langzeit-EKG zu einem etablierten nicht-invasiven elektrophysiologischen Verfahren
entwickelt, das die laborunabhängige EKG-Aufzeichnung unter Alltagsbedingungen über einen längeren Zeitraum ermöglicht und
dadurch eine Fülle von Informationen enthält. Während anfangs das Hauptinteresse vor allem Art und Häufigkeit von Arrhythmien
sowie deren zirkadianes Auftreten und das zirkadiane Verhalten der Herzfrequenz galt, erweiterte sich das Spektrum der Analysemöglichkeiten
im Zuge der technischen Entwicklung, so dass das Langzeit-EKG über die kontinuierliche ST-Streckenanalyse auch zur Diagnostik
myokardialer Ischämien herangezogen wurde. Durch die Entwicklung digitaler Speichermedien und schneller Rechner mit großer
Kapazität wurde die schlaggenaue Vermessung der Herzzyklen möglich, so dass über die Analyse der Herzfrequenzvariabilität
neue Erkenntnisse über die autonome Modulation der Herzfrequenz und über die Vermessung des QT-Intervalls erstmals Einblicke
in dessen zirkadianes Verhalten gewonnen werden konnten. Neben der quantitativen Analyse von Rhythmusstörungen wurde das Langzeit-EKG
in zunehmendem Maße zur Beurteilung der Prognose bei zahlreichen kardialen Grunderkrankungen eingesetzt. Es findet außerdem
Anwendung bei der Abklärung unklarer, vorübergehend auftretender Symptome sowie als Ergänzung der Diagnostik bei Verdacht
auf Schrittmacher- oder ICD-Dysfunktionen, die nicht in jedem Falle durch die Kontrolle der Systeme aufgedeckt werden können.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.