Cardiomegaly is a common arrhythmogenic substrate in adult sudden cardiac deaths, and is associated with obesity

Background: Both coronary artery disease (CAD) and cardiomyopathy may present with sudden cardiac death (SCD). It is generally accepted that CAD is the most common cause of SCD in adults, but the frequency of cardiomegaly as a primary or contributing cause is less known. Methods: We retrospectively studied the cardiac findings of all cases of adult SCD attributed to cardiomegaly, severe atherosclerosis, or both, in the absence of specific cardiomyopathy. Association between findings and risk factors was studied. Results: There were 484 sudden cardiac deaths, of which 402 met study criteria. Mean age was 49 +/- 13 years, with 289 men and 159 African Americans (AAs). Cardiomegaly with presumed hypertensive, multifactorial or unknown cause, was the sole arrhythmogenic substrate in 38% of men and 49% of women (p = 0.003); CAD was the sole cause of SCD in 19% of men and 26% of women, and mixed CAD + cardiomegaly the cause of death in 43% of men and 25% of women. Cardiomegaly was associated by univariate analysis with younger age (46 +/- 12 years versus 53 +/- 14 for CAD, p < 0.0001), AA race (p = 0.004), and body mass index (p < 0.0001). Conclusions: Among adults with a mean age of about 50 years, cardiomegaly is a frequent cause of sudden cardiac death, and is highly associated with obesity. Cardiomegaly is also frequent in SCD with severe CAD. The causes and classification of cardiomegaly in patients without specific cardiomyopathy, and in patients with and without hypertension or coronary disease need to be better studied.