Biphasic effects of alcohol on heart rate are influenced by alcoholic family history and rate of alcohol ingestion.

The present study investigated cardiac response to acute alcohol challenge along the blood alcohol concentration (BAC) curve in two groups of young adult nonalcoholic men with (MFH) and without (FH-) multigenerational family histories of alcoholism, matched for drinking history. BACs and resting heart rate measurements were recorded every 10 min for 3 hr after ingestion of a 1.0 ml/kg dose of 95% USP alcohol at two different rates: one of 20 min (slow drinking) and the other of 5 min (fast drinking). Several analyses of variance were performed for each of the dependent measures [BAC and heart rate change from baseline (HRCH)]. A significant risk x BAC phase interaction emerged from the HRCH analysis, indicating that the MFH group was characterized by a significantly greater increase in resting heart rate along the ascending limb of the BAC curve. A significant risk x BAC phase x rate interaction indicated that, when alcohol was consumed at a faster rate, men with multigenerational family histories of alcoholism demonstrated a greater HRCH, which persisted throughout the BAC curve.