SIGNS OF VAGAL REINNERVATION 4 YEARS AFTER HEART-TRANSPLANTATION IN SPECTRA OF HEART-RATE-VARIABILITY

Several investigators have shown signs of possible sympathetic but not parasympathetic reinnervation in heart transplanted patients. Spectra l analysis of heart rate and blood pressure variability is a noninvasi ve tool appropriate to detect a functional autonomous reinnervation to the heart. In a follow-up study, 13 patients after heart transplantat ion (HTx) were investigated, mean age 50.6 +/- 8.5 years, 18 healthy v olunteers were selected as control group. For each patient two recordi ngs were performed which took part 14 +/- 5 months respectively 42 +/- 8 months after HTx. ECG and systolic blood pressure (SEP) have been r ecorded simultaneously for 5 min in supine position during controlled respiratory rate of 12 or 15 cycles/min. No graft rejection has been d etected in the endomyocardial biopsy performed right after the recordi ngs. Power spectral densities (PSD) were calculated for the beat-to-be at time series of RR-intervals (distance of two following QRS complexe s) and SBPs. The area of PSD in the range of 0.05-0.17 Hz was defined as low frequency (LF) and that of 0.18-0.35 Hz as high frequency (HF). LF and HF are indicative of efferent sympathetic respectively parasym pathetic activity at the sinus node. A significant increase of LF (226 %) and HF (213%) during a mean period of 28 months could be found. No differences were to be shown for systolic blood pressure variability. Previous findings confirm that LF band increases 4 years after transpl antation, suggesting a possible sympathetic reinnervation of the heart . On the other hand an increase of the HF band also suggests a parasym pathetic reinnervation. (C) 1997 Elsevier Science B.V.