Hatice Duygu Bas, Kazim Baser, John Hoyt, Miki Yokokawa, Troy LaBounty, Fred Morady, Frank Bogun

Frequent idiopathic premature ventricular complexes (PVCs) can result in a reversible form of cardiomyopathy. The impact of variability in PVC frequency throughout the day on PVC-induced cardiomyopathy was assessed. The subjects of this study were 107 consecutive patients (58 men [54%], mean age 49.7±15.0 years, ejection fraction: 50.4±11.4%) referred for ablation of frequent PVCs. All patients had a 24 hour Holter prior to the ablation procedure. The circadian variation in PVC burden was determined and correlated with the presence or absence of cardiomyopathy. A total of 43 patients (40%) had cardiomyopathy. Patients with cardiomyopathy had an ejection fraction of 38.4±6.9%, a higher PVC burden (28.5±11.5% vs 19.5±10.5%, p=0.0001), less variability in circadian PVC distribution (Coefficient of variation (CoV) hourly: 31.5±21% vs 59.8±32.4%, p=0.0001), more frequent interpolated PVCs (20 patients [47%] vs 15 patients [23%], p=0.022), and were more frequently asymptomatic compared to patients without cardiomyopathy (56% vs 19%, p=0.0001). By multivariate analysis, consistency in PVC burden throughout the day was an independent predictor of PVC-induced cardiomyopathy (OR 16.3, 95% CI 1.115-155.3, p=0.015). In patients with frequent PVCs, consistency in hourly PVC frequency throughout the day is an independent predictor of PVC-induced cardiomyopathy.