Characteristics of Premature Ventricular Complexes as Correlates of Reduced Left Ventricular Systolic Function: Study of the Burden, Duration, Coupling Interval, Morphology and Site of Origin of PVCs

BACKGROUND: Frequent premature ventricular complexes (PVCs) can cause a decline in left ventricular ejection fraction (LVEF). We investigated whether the site of origin and other PVC characteristics are associated with LVEF. METHODS: We retrospectively studied 70 consecutive patients (mean age 42 ± 17 years, 40 57% female) with no other cause of cardiomyopathy undergoing ablation of PVCs. We analyzed the association of a reduced LVEF, defined by LVEF <50% on echocardiography, with features of PVCs obtained from electrocardiography, 24- or 48-hour Holter monitor and electrophysiology study. RESULTS: Patients with reduced LVEF (n = 17) as compared to normal LVEF (n = 53) had an increased burden of PVCs (29.3 ± 14.6% vs 16.7 ± 13.7%, P = 0.004), higher prevalence of nonsustained ventricular tachycardia (VT) 13 (76%) vs 21 (40%), P = 0.01, longer PVC duration (154.3 ± 22.9 vs 145.6 ± 20.8 ms, P = 0.03) and higher prevalence of multiform PVCs 15 (88%) vs 31 (58%), P = 0.04. There was no significant difference in prevalence of sustained VT, QRS duration of normally conducted complexes, PVC coupling interval, or delay in PVC intrinsicoid deflection. Patients with fascicular PVCs (n = 5) had higher mean LVEF compared to others (66.2 ± 4.0% vs 53.0 ± 10.0%, P = 0.002). There was no association of LVEF with other PVC foci or with left-bundle versus right-bundle branch block morphologies. The threshold burden of PVCs associated with reduced LVEF was lower for right as compared to left ventricular PVCs. CONCLUSION: In addition to the PVC burden, other characteristics like a longer PVC duration, presence of nonsustained VT, multiform PVCs and right ventricular PVCs might be associated with cardiomyopathy.