Impaired Autonomic Nervous System in Alcoholics Assessed by Heart Rate Variation

The suppression of heart rate variation reflects cardiac autonomic nervous dysfunction and is known to be associated with a poor prognosis or sudden death in diabetic patients. We investigated consecutive changes in the heart rate variation in 51 alcoholics using the coefficient of variation of R‐R interval (CV_RR). To correct for age effects, a ratio of CV_RR to the standard predicted value (CV_P) was calculated. On the whole, CV_RR/CV_P was suppressed on admission and on the 7th day of abstinence and increased on the 30th day. However, alcoholics could be divided into two groups by their CV_RR/CV_P on the 30th day: one group with transient autonomic dysfunction whose CV_RR/CV_P was more than 0.8 (n= 32), and the other group with persistent autonomic dysfunction whose CV_RR/CV_P was less than 0.8 (n= 19). Withdrawal hypertension occurred more frequently (63% vs. 19%) and mean systolic pressure (159 ± 24 mmHg vs. 138 ± 17 mmHg) was higher in the latter group than in the former, suggesting that persistent autonomic damage might, at least in part, contribute to withdrawal hypertension. To investigate further the relationship between the persistent autonomic damage and other complications, the CV_RR/CV_P on the 30th day of abstinence was analyzed in an additional 85 alcoholics (total n= 136). Persistent suppression of the CV_RR/CV_P was more frequently found in alcoholics with leg paresthesia (64%, n= 22), the Wernicke‐Korsakoff syndrome (73%, n= 11), or diabetes mellitus (69%, n= 68), than in alcoholics without these complications (31%, n= 35). This suggests that persistent autonomic dysfunction reflects damage in both the peripheral and the central autonomic nervous systems and is exacerbated by the complication of diabetes mellitus. The measurement of CV_RR on the 30th day of abstinence is useful to evaluate persistent autonomic dysfunction in alcoholics.