A Three-Decade Survival Analysis of Intraventricular Conduction Delay in Adults Without Ischemic Heart Disease

The prognosis of an incidental finding of intraventricular conduction delay in individuals without ischemic heart disease is debatable. Intraventricular conduction delay presents electrocardiographically as bundle branch block or nonspecific intraventricular conduction delay. We aimed to assess the long-term survival of an incidental intraventricular conduction delay finding in a cohort of individuals without ischemic heart disease, followed up for 3 decades.

A randomized stratified cohort of the adult Israeli population underwent medical examinations and electrocardiography between 1976 and 1982. Patients with ischemic heart disease were excluded, and the cohort was followed for all-cause mortality for a median of 30.4 years. Major intraventricular conduction delay was defined as having complete bundle branch block or nonspecific intraventricular conduction delay, and minor intraventricular conduction delay was defined as having incomplete bundle branch block. Cox proportional hazard model was performed, comparing individuals by electrocardiogram finding, adjusting for demographic, clinical, and electrocardiographic variables.

Of 2465 subjects, 2385 (96.8%) were without intraventricular conduction delay, 38 (1.5%) had minor intraventricular conduction delay, and 42 (1.7%) had major intraventricular conduction delay. All-cause mortality rates were higher among minor and major intraventricular conduction delay groups (57.9% and 66.7%, P = .43 and P = .04, respectively) compared with no intraventricular conduction delay (52.1%). By controlling for sex, age, and body mass index, intraventricular conduction delay was not associated with all-cause mortality: hazard ratios, 0.82 (95% confidence interval, 0.52-1.25) and 1.06 (95% confidence interval, 0.72-1.54) for minor and major intraventricular conduction delay, respectively.

Intraventricular conduction delay was not found to be an independent risk factor for all-cause mortality in individuals without ischemic heart disease.