Prevalence of cardiomegaly and left ventricular hypertrophy in scuba diving and traffic accident victims.

Although frequently asymptomatic, left ventricular hypertrophy (LVH) is an independent predictor of sudden cardiac death (SCD). We hypothesized that diving may increase the propensity for pre-existent LVH to cause a lethal arrhythmia (and SCD) and therefore the prevalence of LVH may be greater among scuba fatalities than among traffic fatalities. We compared autopsy data for 100 scuba fatalities with 178 traffic fatalities. Extracted data contained information on age, sex, height, body mass, heart mass (HM), left ventricular wall thickness (LVWT), interventricular wall thickness (IVWT), and degree of coronary artery stenosis. A case was classified as LVH if the LVWT was > 15 mm. Log risk models were used to compare HM and LVWT in two groups while controlling for body mass, body length, age and sex. The prevalence of LVH was compared using Pearson's test. The mean HM was 428.3 +/- 100 for divers and 387 +/- 87 for controls. The crude HM ratio for scuba fatalities vs. controls was 1.11 (1.05, 1.17), and when controlled for sex, age and body mass the ratio was 1.06 (1.01, 1.09). The mean LVWT was 15 +/- 3.5 for divers and 14 +/- 2.7 for controls (p = 0.0017). HM and LVWT measured at autopsy were greater in scuba than in traffic fatalities.