[A study of cardiac vagal function in chronic alcoholics]

Reduced cardiac vagal tonus is correlated to sudden cardiac death and occurrence of arrhythmia, particularly in patients with ischemic heart disease. In patients with diabetic neuropathy increased frequencies of silent myocardial ischaemia and silent myocardial infarctions have been found, in addition. The object of the present investigation was to assess whether chronic alcoholics have lowered cardiac vagal tonus. The cardiac vagal tonus was assessed by means of a sensitive non-invasive method in which the variations in the pulse rate during six deep respirations were registered on the basis of the R to R interval in the ECG. Fourteen alcoholics and fourteen healthy controlled individuals participated in the investigation. The medians of the variations in the two groups were 15 and 25 beats per minute, respectively. The difference was statistically significant. No significant differences were observed in alcoholics with or without clinical evidence of polyneuropathy. This investigation thus suggests that ethanol has a toxic effect on the cardiac vagal function.