EVIDENCE FOR DIFFERENTIAL SYMPATHETIC AND PARASYMPATHETIC REINNERVATION AFTER HEART-TRANSPLANTATION IN HUMANS

During heart transplantation (HTX) all neural connections are severed, Ln humans, signs of autonomic reinnervation have been found, in this study non-invasive tests were used to compare signs of sympathetic and parasympathetic reinnervation. Non-invasive autonomic function tests and heart rate variability parameters (HRV; 24 h electrocardiographic registration) were used to investigate signs of reinnervation, 16 HTX patients (14 males) were compared with age-and sex-matched controls, P arasympathetic heart rate changes in HTX compared to controls were att enuated during the diving test, deep breathing, the Valsalva maneuver and standing up but not during carotid sinus massage, Sympathetic hear t rate increases were lower during the cold presser test and mental st ress, The blood pressure responses were comparable to the control grou p, but not during active standing and tilting. This finding suggests a n obligatory 'blood pressure' role for the innervated heart in these t wo tests, All HRV parameters were lower in HTX. One or more normal par asympathetic responses were found in 13 out of 16 patients versus 4 ou t of 16 with normal sympathetic responses (p < 0.05). Heart rate varia tions were less in case of a higher donor age, and higher in case of a longer time after HTX. Parasympathetic signs of reinnervation are mor e common than sympathetic signs of reinnervation, A higher donor age r educes signs of reinnervation. Lf the sympatho-vagal balance is a prog nostic factor in HTX patients as it is in other cardiac diseases these findings are clinically relevant. (C) 1997 Elsevier Science B.V.