Cardiac reactivity during the ascending phase of acute intravenous alcohol exposure and association with subjective perceptions of intoxication in social drinkers

BACKGROUND

The aim of this study was to characterize cardiac reactivity measures, heart rate (HR), and heart rate variability (HRV), following acute intravenous (IV) alcohol administration and their association with subjective responses in social drinkers.

METHODS

Twenty-four subjects (11 females) received IV alcohol infusions to attain and clamp the breath alcohol concentration (BrAC) at 50 mg% or placebo in separate sessions. Serial 5-minute cardiac recordings at baseline and during the infusion were analyzed to obtain frequency and time domain cardiac measures. Self-reported subjective perceptions were also obtained at the same time points.

RESULTS

HR showed significant decreases from baseline, while the HRV measure pNN50 showed steady increases during the ascending phase of alcohol infusion. HR was inversely correlated with pNN50 across time and treatment. There was a significant association of HR with subjective feelings of high, intoxication, feeling drug effects, and liking drug effects across time during the ascending phase.

CONCLUSIONS

Acute IV alcohol resulted in decreases in HR and increases in HRV consistent with autonomic parasympathetic activation. The association of these changes with subjective responses suggests that cardiac reactivity may serve as a physiological marker of subjective alcohol effects. This study broadens the understanding of acute cardiovascular effects of alcohol and clinically significant cardiac conditions such as arrhythmia and cardiomyopathy associated with chronic alcohol drinking.

Effects of family history of alcohol dependence on the subjective response to alcohol using the intravenous alcohol clamp

BACKGROUND

Alcohol use disorders are well recognized to be common, debilitating, and the risk of developing them is influenced by family history (FH). The subjective response to alcohol may be determined familialy and related to the risk of developing alcoholism. The aim of this study was to evaluate differences between family history positive (FHP) and family history negative (FHN) individuals in their response to alcohol within the domains of subjective, coordination, and cognitive effects using an intravenous (IV) clamping method of alcohol administration.

METHODS

Two groups of healthy subjects, those with an FHP (n = 65) versus those who were FHN (n = 115), between the ages of 21 to 30, participated in 3 test days. Subjects were scheduled to receive placebo, low-dose ethanol (EtOH) (target breath alcohol clamping [BrAC] = 40 mg%), and high-dose EtOH (target BrAC = 100 mg%) on 3 separate test days at least 3 days apart in a randomized order under double-blind conditions. Outcome measures included subjective effects, measures of coordination, and cognitive function.

RESULTS

Both low- and high-dose alcohol led to dose-related stimulant and sedative subjective effects as measured the Biphasic Alcohol Effects Scale and subjective measures of "high" and "drowsy" measured on a visual analog scale. However, there were no effects of FH. Similar dose-related effects were observed on cognitive and coordination-related outcomes, but were not moderated FH.

CONCLUSIONS

Results from this study showed that healthy individuals responded to an IV alcohol challenge in a dose-related manner; however, there were no significant differences on subjective response, or on EtOH-induced impairment of coordination or cognition, between individuals with a positive FH for alcoholism and those with a negative FH. Results suggest that FH may not be a specific enough marker of risk, particularly in individuals who are beyond the age where alcohol use disorders often develop.