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BACKGROUND: Premature ventricular contractions (PVCs) are frequently observed with left ventricular (LV) systolic dysfunction, although the prevalence of these associated conditions in the general population remains unknown. OBJECTIVE: We sought to understand the prevalence of frequent PVCs (defined PVCs > 5%) and high burden PVCs (defined PVCs > 10%) and LV systolic dysfunction in patients receiving ambulatory Holter monitors (HM). METHODS: A prospective multicenter (eight US medical centers) cross-sectional study collected demographic and PVC burden data from consecutive patients undergoing 24-h, 48-h, and 14-day HM (July 2018-June 2020). Left ventricle ejection fraction (LVEF) data was collected if obtained within 6 months of HM. Four PVC burden groups were analyzed (10% burden) and stratified by normal LVEF (≥50%) or presence LVEF 10% was 4% and 5%, respectively in the population undergoing HM (n = 6529). Age was significantly different between PVC groups (p  5% was 16.4% and 4.2%, respectively. The prevalence of PVC > 5% and PVC > 10% in patients with LVEF  5% were more prevalent in older, male, and Caucasians (p  5% than males (6% vs. 11%; p  5% and PVC > 10% and LVEF  5% are associated with older age. Females have a lower prevalence of PVC > 5% than males but similar combined PVC > 5% and LVEF

Background Ethnic medicine holds numerous advantages in the treatment of premature ventricular complexes (PVCs). However, there is a concerning trend of abuse of ethnic medicine, particularly in the absence of tailored clinical drug recommendations specifically designed for this purpose. Consequently, it is of crucial importance to standardize the diagnosis and treatment of PVCs within the context of ethnic medicine. Objective To establish the clinical problems and outcome indicators of the Expert Consensus on Clinical Application of Ethnic Medicine in the Treatment of Palpitation (Arrhythmia-Premature Ventricular Complexes) . Methods The inquiring experts were members of the consensus expert group, encompassing experts in the fields of cardiology, evidence-based medicine, and pharmacology. Specifically, within cardiology, they comprised multi-ethnic medical experts in traditional Chinese medicine, Tibetan medicine, Mongolian medicine, Uyghur medicine, Dai medicine, Korean medicine, and Zhuang medicine. Drawing from the available literature and expert interview reports, the research team conducted a comprehensive search of relevant literature on the treatment of PVCs using various ethnic medical practices. In April 2023, a series of one-on-one online interviews were conducted with 14 multi-ethnic medical experts. Following the integration of the interview results and expert experiences, the consensus steering committee and working group jointly drafted the initial proposals for clinical questions and outcome indicators, subsequently designing a survey questionnaire. Between May and July 2023, two rounds of questionnaire surveys were conducted, rigorously evaluating the positivity, concentration, coordination, and reliability of the questionnaire responses. Results The expert panel was characterized by its multidisciplinary collaboration, authority, and geographical representation. The two rounds of the Delphi method yielded a positive coefficient of 99.1%. For the five background questions, the mean score was greater than 4, with the full scale exceeding 40%. For the ten prospective questions, the mean score was greater than 3.9, with the full scale surpassing 35%. Additionally, the nine outcome indicators achieved a mean score greater than 7, with the full scale exceeding 30%. The mean coefficient of variation for these metrics was 14.9%, 16.3%, and 17.6%. The Kendall harmony coefficients for clinical questions and outcome indicators were 0.267 and 0.316. The chi-square test showed a P-value of less than 0.05. The Cronbach's α coefficients were 0.913 and 0.905, both exceeding 0.7, suggesting high reliability. Overall, the quality control results were satisfactory, indicating a high degree of credibility in the questionnaire design. Conclusion Utilizing the Delphi method, we have identified the clinical problems and outcome indicators that need to be addressed in the development of the Expert Consensus on Clinical Application of Ethnic Medicine in the Treatment of Palpitation (Arrhythmia-Premature Ventricular Complexes), laying a solid foundation for the subsequent formulation of the consensus.

During the acute phase of subarachnoid hemorrhage, cardiac rhythm disturbances are frequently observed, affecting 50% to 100% of patients. Although benign arrhythmias like sinus tachycardia, sinus bradycardia, premature atrial contractions, and premature ventricular contractions are common, clinically significant arrhythmias such as ventricular tachycardia or atrial tachyarrhythmias manifest in only 1-4% of patients. This case report delves into the intricate connection between cardiac complications and neurological emergencies, using a distinctive bigeminy rhythm presentation in a 43-year-old male patient with aneurysmal subarachnoid hemorrhage. [ABSTRACT FROM AUTHOR]

In-hospital electrocardiographic (ECG) monitors are typically configured to alarm for premature ventricular complexes (PVCs) due to the potential association of PVCs with ventricular tachycardia (VT). However, no contemporary hospital-based studies have examined the association of PVCs with VT. Hence, the benefit of PVC monitoring in hospitalized patients is largely unknown. This secondary analysis used a large PVC alarm data set to determine whether PVCs identified during continuous ECG monitoring were associated with VT, in-hospital cardiac arrest (IHCA), and/or death in a cohort of adult intensive care unit patients. Six PVC types were examined (i.e., isolated, bigeminy, trigeminy, couplets, R-on-T, and run PVCs) and were compared between patients with and without VT, IHCA, and/or death. Of 445 patients, 48 (10.8%) had VT; 11 (2.5%) had IHCA; and 49 (11%) died. Isolated and run PVC counts were higher in the VT group (p = 0.03 both), but group differences were not seen for the other four PVC types. The regression models showed no significant associations between any of the six PVC types and VT or death, although confidence intervals were wide. Due to the small number of cases, we were unable to test for associations between PVCs and IHCA. Our findings suggest that we should question the clinical relevance of activating PVC alarms as a forewarning of VT, and more work should be done with larger sample sizes. A more precise characterization of clinically relevant PVCs that might be associated with VT is warranted.

BACKGROUND: Large-scale data on incidental premature ventricular contraction (PVC) prevalence and morphologies have been lacking, leaving many providers without guidance on further cardiac testing for patients with incidental PVCs on ECG. Athletes offer an intriguing cohort to understand the clinical significance, prevalence, and common morphologies of incidental PVCs because they often undergo ECG screening during preparticipation exams. METHODS: Digital ECGs were obtained from 10 728 screened athletes aged 14 to 35 years during mass screenings in schools and professional sports teams between 2014 and 2021. A retrospective analysis of ECGs with PVCs was performed using the simultaneous display of frontal (limb) and horizontal (precordial) plane leads. PVCs were coded for morphology and categorized as benign or nonbenign using recommended criteria. RESULTS: Twenty-six athletes (0.24%) were found to have at least 1 PVC. Among these, 50% were female, 65% were White, 8% were Asian, 4% were Hispanic, and 23% were Black. Nineteen of the 26 (73%) ECGs had PVCs with a left bundle branch block pattern compared with 7 (27%) with a right bundle branch block pattern. Twenty-four ECGs (96%) had PVCs with benign patterns, including 18 with right ventricular outflow tract, 5 with left anterior fascicle, and 2 with left posterior fascicle morphology. CONCLUSIONS: There is a low prevalence of PVCs on routine ECG screening of young athletes, and most PVCs are of benign morphology in this population. This study highlights the value of using digital ECG recorders with simultaneous lead display to guide decision-making about further cardiac testing and referrals in young athletes with PVCs. Using our results and review of the literature, we propose methods and algorithms of PVC evaluation on screening ECGs to help guide many providers with risk stratification and decision-making about further cardiac testing and electrophysiology referrals in young athletes with PVCs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pulsed field ablation (PFA) is a novel technology for catheter-based atrial arrhythmia treatment. Evidence of its application for ventricular arrhythmia ablation is still limited. In this study, we describe the feasibility and efficacy of focal PFA for premature ventricular contraction (PVC) ablation. METHODS: A prospective cohort of 20 patients referred for PVC ablation at 2 centers was enrolled, regardless of the presence of structural heart disease, PVC morphology, or previous ablation attempts. All procedures were performed using the CENTAURI System in combination with contact force sensing catheters and 3-dimensional electroanatomical mapping systems. Energy output and the number of applications were left to the operator’s discretion. RESULTS: Eleven (55%) procedures were conducted under general anesthesia, 6 (30%) under deep sedation, and 3 (15%) under light sedation. Muscular contraction was observed in one case (5%). Median procedural and fluoroscopy times were 95.5 and 6.55 minutes, respectively. The median number of PFA applications was 8 with a median contact force of 10g. A statistically significant (76%) reduction was observed in mean peak-to-peak bipolar electrogram voltage before and after ablation (0.707 versus 0.098 mV; P=0.008). Ventricular irritative firing was observed in 11 (55%) patients after PFA. The median follow-up was 120 days. Acute procedural success was achieved in 17 of 20 (85% [95% CI, 0.70–1]) patients. Two of the patients with procedural failure had late success with >80% clinical PVC burden suppression during follow-up, and 2 of 17 patients with acute success had late PVC recurrence, which accounts for a total of 17 of 20 (85% [95% CI, 0.70–1]) patients with chronic success. Transient ST-segment depression occurred in 1 patient, and the right bundle branch block was induced in 2 others (permanently only in one case). CONCLUSIONS: PVC ablation using a focal PFA is feasible, effective, and safe, with promising acute and long-term results in several ventricular locations. Irritative firing is frequently observed. Coronary evaluation should be considered when targeting the outflow tract. [ABSTRACT FROM AUTHOR]

Aims A pulsed electric field (PF) energy source is a novel potential option for catheter ablation of ventricular arrhythmias (VAs) as it can create deeper lesions, particularly in scarred tissue. However, very limited data exist on its efficacy and safety. This prospective observational study reports the initial experience with VA ablation using focal PF. Methods and results The study population consisted of 44 patients (16 women, aged 61 ± 14years) with either frequent ventricular premature complexes (VPCs, 48%) or scar-related ventricular tachycardia (VT, 52%). Ablation was performed using an irrigated 4 mm tip catheter and a commercially available PF generator. On average, 16 ± 15 PF applications (25 A) were delivered per patient. Acute success was achieved in 84% of patients as assessed by elimination of VPC or reaching non-inducibility of VT. In three cases (7%), a transient conduction system block was observed during PF applications remotely from the septum. Root analysis revealed that this event was caused by current leakage from the proximal shaft electrodes in contact with the basal interventricular septum. Acute elimination of VPC was achieved in 81% patients and non-inducibility of VT in 83% patients. At the 3-month follow-up, persistent suppression of the VPC was confirmed on Holter monitoring in 81% patients. In the VT group, the mean follow-up was 116 ± 75 days and a total of 52% patients remained free of any VA. Conclusion Pulsed electric field catheter ablation of a broad spectrum of VA is feasible with acute high efficacy; however, the short-term follow-up is less satisfactory for patients with scar-related VT. [ABSTRACT FROM AUTHOR]

BackgroundCoffee is one of the most commonly consumed beverages in the world, but the acute health effects of coffee consumption remain uncertain.MethodsWe conducted a prospective, randomized, case-crossover trial to examine the effects of caffeinated coffee on cardiac ectopy and arrhythmias, daily step counts, sleep minutes, and serum glucose levels. A total of 100 adults were fitted with a continuously recording electrocardiogram device, a wrist-worn accelerometer, and a continuous glucose monitor. Participants downloaded a smartphone application to collect geolocation data. We used daily text messages, sent over a period of 14 days, to randomly instruct participants to consume caffeinated coffee or avoid caffeine. The primary outcome was the mean number of daily premature atrial contractions. Adherence to the randomization assignment was assessed with the use of real-time indicators recorded by the participants, daily surveys, reimbursements for date-stamped receipts for coffee purchases, and virtual monitoring (geofencing) of coffee-shop visits.ResultsThe mean (±SD) age of the participants was 39±13 years; 51% were women, and 51% were non-Hispanic White. Adherence to the random assignments was assessed to be high. The consumption of caffeinated coffee was associated with 58 daily premature atrial contractions as compared with 53 daily events on days when caffeine was avoided (rate ratio, 1.09; 95% confidence interval [CI], 0.98 to 1.20; P = 0.10). The consumption of caffeinated coffee as compared with no caffeine consumption was associated with 154 and 102 daily premature ventricular contractions, respectively (rate ratio, 1.51; 95% CI, 1.18 to 1.94); 10,646 and 9665 daily steps (mean difference, 1058; 95% CI, 441 to 1675); 397 and 432 minutes of nightly sleep (mean difference, 36; 95% CI, 25 to 47); and serum glucose levels of 95 mg per deciliter and 96 mg per deciliter (mean difference, -0.41; 95% CI, -5.42 to 4.60).ConclusionsIn this randomized trial, the consumption of caffeinated coffee did not result in significantly more daily premature atrial contractions than the avoidance of caffeine. (Funded by the University of California, San Francisco, and the National Institutes of Health; CRAVE ClinicalTrials.gov number, NCT03671759.).

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Abstract Background Apparently healthy dogs of various breeds eating nontraditional, high‐pulse diets can have larger left ventricular diameter, lower systolic function, and more ventricular premature complexes (VPCs) compared with dogs eating traditional, low‐pulse diets. It is unknown whether Irish Wolfhounds eating high‐pulse diets have similar cardiac abnormalities. Hypothesis/Objectives To compare electrocardiographic and echocardiographic findings between Irish Wolfhounds eating high‐ or low‐pulse diets. Animals Ninety‐seven Irish Wolfhounds. Methods Retrospective study of Irish Wolfhounds that had echocardiography performed at dog shows between October 2018 and May 2021. Demographic information, echocardiographic measurements, cardiac rhythm (1‐minute lead II rhythm strip), and main diet were recorded retrospectively. Diets were classified as high‐pulse or low‐pulse based on the presence and location of pulses (peas, lentils, chickpeas, or dry beans) on the ingredient list. Results Thirty‐five of 97 Irish Wolfhounds (36%) were eating high‐pulse diets and 62 of 97 (64%) were eating low‐pulse diets. There were no significant differences between diet groups in echocardiographic measurements. A significantly higher percentage of dogs in the high‐pulse diet group (6/35 [17%]) had VPCs compared with those in the low‐pulse diet group (1/62 [2%]; effect size = 0.15 [95% confidence interval: 0.004‐0.31]; P = .005). Conclusions and Clinical Importance In this retrospective study of apparently healthy Irish Wolfhounds, high‐pulse diets were associated with a higher prevalence of VPCs which could represent early cardiac abnormalities.

Background: Apparently healthy dogs of various breeds eating nontraditional, high‐pulse diets can have larger left ventricular diameter, lower systolic function, and more ventricular premature complexes (VPCs) compared with dogs eating traditional, low‐pulse diets. It is unknown whether Irish Wolfhounds eating high‐pulse diets have similar cardiac abnormalities. Hypothesis/Objectives: To compare electrocardiographic and echocardiographic findings between Irish Wolfhounds eating high‐ or low‐pulse diets. Animals: Ninety‐seven Irish Wolfhounds. Methods: Retrospective study of Irish Wolfhounds that had echocardiography performed at dog shows between October 2018 and May 2021. Demographic information, echocardiographic measurements, cardiac rhythm (1‐minute lead II rhythm strip), and main diet were recorded retrospectively. Diets were classified as high‐pulse or low‐pulse based on the presence and location of pulses (peas, lentils, chickpeas, or dry beans) on the ingredient list. Results: Thirty‐five of 97 Irish Wolfhounds (36%) were eating high‐pulse diets and 62 of 97 (64%) were eating low‐pulse diets. There were no significant differences between diet groups in echocardiographic measurements. A significantly higher percentage of dogs in the high‐pulse diet group (6/35 [17%]) had VPCs compared with those in the low‐pulse diet group (1/62 [2%]; effect size = 0.15 [95% confidence interval: 0.004‐0.31]; P =.005). Conclusions and Clinical Importance: In this retrospective study of apparently healthy Irish Wolfhounds, high‐pulse diets were associated with a higher prevalence of VPCs which could represent early cardiac abnormalities. [ABSTRACT FROM AUTHOR]

BACKGROUND: The accuracy of noninvasive arrhythmia source localization using a forward-solution computational mapping system has not yet been evaluated in blinded, multicenter analysis. This study tested the hypothesis that a computational mapping system incorporating a comprehensive arrhythmia simulation library would provide accurate localization of the site-of-origin for atrial and ventricular arrhythmias and pacing using 12-lead ECG data when compared with the gold standard of invasive electrophysiology study and ablation. METHODS: The VMAP study (Vectorcardiographic Mapping of Arrhythmogenic Probability) was a blinded, multicenter evaluation with final data analysis performed by an independent core laboratory. Eligible episodes included atrial and ventricular: tachycardia, fibrillation, pacing, premature atrial and ventricular complexes, and orthodromic atrioventricular reentrant tachycardia. Mapping system results were compared with the gold standard site of successful ablation or pacing during electrophysiology study and ablation. Mapping time was assessed from time-stamped logs. Prespecified performance goals were used for statistical comparisons. RESULTS: A total of 255 episodes from 225 patients were enrolled from 4 centers. Regional accuracy for ventricular tachycardia and premature ventricular complexes in patients without significant structural heart disease (n=75, primary end point) was 98.7% (95% CI, 96.0%-100%; P

Initiation of reentry requires 2 factors: (1) a triggering event, most commonly focal excitations such as premature ventricular complexes (PVCs); and (2) a vulnerable substrate with regional dispersion of refractoriness and/or excitability, such as occurs during the T wave of the electrocardiogram when some areas of the ventricle have repolarized and recovered excitability but others have not. When the R wave of a PVC coincides in time with the T wave of the previous beat, this timing can lead to unidirectional block and initiation of reentry, known as the R-on-T phenomenon. Classically, the PVC triggering reentry has been viewed as arising focally from 1 region and propagating into another region whose recovery is delayed, resulting in unidirectional conduction block and reentry initiation. However, more recent evidence indicates that PVCs also can arise from the T wave itself. In the latter case, the PVC initiating reentry is not a separate event from the T wave but rather is causally generated from the repolarization gradient that manifests as the T wave. We call the former an R-to-T mechanism and the latter an R-from-T mechanism, which are initiation mechanisms distinct from each other. Both are important components of the R-on-T phenomenon and need to be taken into account when designing antiarrhythmic strategies. Strategies targeting suppression of triggers alone or vulnerable substrate alone may be appropriate in some instances but not in others. Preventing R-from-T arrhythmias requires suppressing the underlying dynamic tissue instabilities responsible for producing both triggers and substrate vulnerability simultaneously. The same principles are likely to apply to supraventricular arrhythmias.

The Life's Simple 7 (LS7) metric consists of 7 modifiable health behaviors and measures that are known health factors for cardiovascular wellness. Relatively little is known about the association of LS7 score with cardiac arrhythmias. In the setting of the Multi-Ethnic Study of Atherosclerosis, we studied the LS7 score (range 0 to 14), assessed at the 2010 to 2102 study visit, in relation to cardiac arrhythmias assessed by Zio Patch ambulatory electrocardiographic monitoring in 2016 to 2018. In participants free of clinically recognized cardiovascular disease and atrial fibrillation, we used logistic and linear regression to examine the association of total LS7 score with atrial fibrillation, supraventricular ectopy, and ventricular ectopy. In 1,329 participants in the analysis, the mean (SD) age was 67 (8) years and 48% were men. A more favorable total LS7 score was associated with fewer premature ventricular contractions (PVCs) per hour (ratio of geometric means for optimal [11 to 14] versus inadequate [0 to 7] score 0.52 [95% confidence interval 0.34 to 0.81]). After adjustment for sociodemographic characteristics, the association was attenuated (0.66 [0.43 to 1.01]). =Among the LS7 components, a more favorable body mass index was associated with less ventricular ectopy. We did not detect associations of total LS7 score with atrial arrhythmias. In conclusion, in this longitudinal study of older participants free of clinically recognized cardiovascular disease, there was little evidence of association of the LS7 cardiovascular health score with subclinical cardiac arrhythmias. However, there was a suggestion that a more favorable LS7 score was associated with fewer PVCs and specifically, that a more favorable body mass index was associated with fewer PVCs.

BackgroundThe short-coupled variant of torsade de pointes (sc-TdP) is a malignant arrhythmia that frequently presents with ventricular fibrillation (VF) electrical storm. Verapamil is considered the first-line therapy of sc-TdP while catheter ablation is not widely adopted. The aim of this study was to determine the origin of sc-TdP and to assess the outcome of catheter ablation using 3D-mapping.Methods and resultsWe retrospectively analyzed five patients with sc-TdP who underwent 3D-mapping and ablation of sc-TdP at five different institutions. Four patients initially presented with sudden cardiac arrest, one patient experienced recurrent syncope as the first manifestation. All patients demonstrated a monomorphic premature ventricular contraction (PVC) with late transition left bundle branch block pattern, superior axis, and a coupling interval of less than 300 ms. triggering recurrent TdP and VF. In four patients, the culprit PVC was mapped to the free wall insertion of the moderator band (MB) with a preceding Purkinje potential in two patients. Catheter ablation using 3D-mapping and intracardiac echocardiography eliminated sc-TdP in all patients, with no recurrence at mean 2.7 years (range 6 months to 8 years) of follow-up.Conclusion3D-mapping and intracardiac echocardiography demonstrate that sc-TdP predominantly originates from the MB free wall insertion and its Purkinje network. Catheter ablation of the culprit PVC at the MB free wall junction leads to excellent short- and long-term results and should be considered as first-line therapy in recurrent sc-TdP or electrical storm.

BackgroundRight ventricular outflow tract (RVOT) is a common source of ventricular tachycardia, which often requires ablation. However, the mechanisms underlying the RVOT's unique arrhythmia susceptibility remain poorly understood due to lack of detailed electrophysiological and molecular studies of the human RVOT.MethodsWe conducted optical mapping studies in 16 nondiseased donor human RVOT preparations subjected to pharmacologically induced adrenergic and cholinergic stimulation to evaluate susceptibility to arrhythmias and characterize arrhythmia dynamics.ResultsWe found that under control conditions, RVOT has shorter action potential duration at 80% repolarization relative to the right ventricular apical region. Treatment with isoproterenol (100 nM) shortened action potential duration at 80% repolarization and increased incidence of premature ventricular contractions (P=0.003), whereas acetylcholine (100 μM) stimulation alone had no effect on action potential duration at 80% repolarization or premature ventricular contractions. However, acetylcholine treatment after isoproterenol stimulation reduced the incidence of premature ventricular contractions (P=0.034) and partially reversed action potential duration at 80% repolarization shortening (P=0.029). Immunolabeling of RVOT (n=4) confirmed the presence of cholinergic marker VAChT (vesicular acetylcholine transporter) in the region. Rapid pacing revealed RVOT susceptibility to both concordant and discordant alternans. Investigation into transmural arrhythmia dynamics showed that arrhythmia wave fronts and phase singularities (rotors) were relatively more organized in the endocardium than in the epicardium (P=0.006). Moreover, there was a weak but positive spatiotemporal autocorrelation between epicardial and endocardial arrhythmic wave fronts and rotors. Transcriptome analysis (n=10 hearts) suggests a trend that MAPK (mitogen-activated protein kinase) signaling, calcium signaling, and cGMP-PKG (protein kinase G) signaling are among the pathways that may be enriched in the male RVOT, whereas pathways of neurodegeneration may be enriched in the female RVOT.ConclusionsHuman RVOT electrophysiology is characterized by shorter action potential duration relative to the right ventricular apical region. Cholinergic right ventricular stimulation attenuates the arrhythmogenic effects of adrenergic stimulation, including increase in frequency of premature ventricular contractions and shortening of wavelength. Right ventricular arrhythmia is characterized by positive spatial-temporal autocorrelation between epicardial-endocardial arrhythmic wave fronts and rotors that are relatively more organized in the endocardium.

ObjectiveA higher premature ventricular complex (PVC) frequency is associated with incident congestive heart failure (CHF) and death. While certain PVC characteristics may contribute to that risk, the current literature stems from patients in medical settings and is therefore prone to referral bias. This study aims to identify PVC characteristics associated with incident CHF in a community-based setting.MethodsThe Cardiovascular Health Study is a cohort of community-dwelling individuals who underwent prospective evaluation and follow-up. We analysed 24-hour Holter data to assess PVC characteristics and used multivariable logistic and Cox proportional hazards models to identify predictors of a left ventricular ejection fraction (LVEF) decline and incident CHF, respectively.ResultsOf 871 analysed participants, 316 participants exhibited at least 10 PVCs during the 24-hour recording. For participants with PVCs, the average age was 72±5 years, 41% were women and 93% were white. Over a median follow-up of 11 years, 34% developed CHF. After adjusting for demographics, cardiovascular comorbidities, antiarrhythmic drug use and PVC frequency, a greater heterogeneity of the PVC coupling interval was associated with an increased risk of LVEF decline and incident CHF. Of note, neither PVC duration nor coupling interval duration exhibited a statistically significant relationship with either outcome.ConclusionsIn this first community-based study to identify Holter-based features of PVCs that are associated with LVEF reduction and incident CHF, the fact that coupling interval heterogeneity was an independent risk factor suggests that the mechanism of PVC generation may influence the risk of heart failure.