Lack of recovery of baroreflex function in hypertensive patients after heart surgery

Baroreflex sensitivity (BRS) and heart rate variability (HRV) have significant influence on the patients´ prognosis after cardiovascular events. The following study was performed to assess differences in the response of the autonomic regulation in hypertensive and normotensive patients undergoing cardiac surgery with heart-lung machine. 166 consecutive patients were enrolled in a prospective study; 102 of them were hypertensive according to the criteria of the WHO. Cardiovascular signals were recorded the day before, 24 h after surgery and one week after surgery. SDNN steeply declined in Hypertensives 24 h after the operation (46.5 vs. 24.5ms, p<10-7 ), the decline in Normotensives was less pronounced (52 vs. 30.8ms, p<0.01).The mean number of bradycardic fluctuations of BRS decreased in both groups at 24 h, then there was recovery in Normotensives after one week, but not in Hypertensives. While the response to surgery is similar in normotensive and hypertensive patients, there obviously is a decreased ability to recover in hypertensives.