[Return of circadian blood pressure and heart rate changes in patients with heart transplants]

A loss of the circadian rhythm pattern of blood pressure (BP) and heart rate, as well as the development of hypertension have been found after heart transplantation (Htx). To study whether a return of this rhythm occurs in the long-term after Htx, we used 24-h ambulatory monitoring to study 62 patients 5 days to 6.5 years after Htx. Patients were divided into two groups (Group 1: less than 6 months after Htx (n = 30), Group 2: 6 months or more after Htx (n = 32)). Group 2 had a higher BP and heart rate, as well as a significantly higher difference between systolic day and systolic night BP than group 1. There was also a significantly higher difference in heart rate between day and night values in group 2. The return of the circadian rhythm pattern in the longer term after heart transplantation may result from partial reinnervation of the heart, although other neurohumoral factors or concomitant medication may play a role.