Abstract

Ventricular premature complexes (VPCs) and atrial premature complexes (APCs) are common findings on routinely obtained electrocardiograms. Despite their common occurrence, the significance of these irregular beats is unclear, especially with regard to risk of sudden cardiac death (SCD). In this study, we examined the prospective relation between baseline VPCs or APCs and SCD, myocardial infarction, and fatal coronary heart disease (CHD) in a population-based sample of subjects from the Atherosclerosis Risk in Communities (ARIC) study excluding participants with known history of CHD or stroke. Baseline examination was conducted from 1987 to 1989, with follow-up data regarding clinical cardiac events collected until December 2002. The total study population was 14,574 subjects. Kaplan-Meier curves and computed univariate and multivariate Cox proportional hazard models were employed to estimate the effect of VPC and APC occurrences on incident cardiac events. During the follow-up period, there were 130 incident cases of SCD, 1,657 incident cases of CHD cases, and 288 cases of fatal CHD. Participants with VPC were 2 times as likely to have SCD (hazard ratio [HR] 2.09, 95% confidence interval [CI] 1.22 to 3.56) compared to those without VPC. Presence of APC was not significantly associated with SCD (HR 1.15, 95% CI 0.56 to 2.39). Compared to subjects without VPC and APC, risk of SCD in subjects with VPC and APC was significantly increased (HR 6.39, 95% CI 2.58 to 15.84). In conclusion, our study shows that subjects with VPCs are significantly more likely to die from SCD, despite not having any known history of cardiovascular disease. This effect appears to be additive when APCs occur concurrently.