Cardiac transplantation significantly reduced heart rate variability compared to normal subjects (log total power -0.766 vs 0.982; p<0.0001), whereas allograft rejection increased it (p<0.02).
Observational (n=23)
Does cardiac transplantation and subsequent allograft rejection alter heart rate variability?
Cardiac denervation from transplantation significantly reduces heart rate variability, but the development of allograft rejection may increase it.
Absolute Event Rate: -0.766% vs 0.982%
p-value: p=<0.0001
Beat-to-beat heart rate variability was studied by power spectral analysis in 17 orthotopic cardiac transplant patients. Heart rate power spectra were calculated from eighty-four 256-second recordings and compared with those taken from six normal subjects. The power spectra from the control subjects resolved into discrete peaks at 0.04-0.12 Hz and 0.2-0.3 Hz, whereas those of heart transplant recipients resembled broad-band noise without peaks. Log total power in the 0.02-1.0 Hz range was greater in the control subjects (0.982 +/- 0.084 0.206, mean +/- SEM SD) than in the transplanted subjects (-0.766 +/- 0.059 0.541), (p less than 0.0001). Fifty-five electrocardiographic recordings from transplant patients were done within 48 hours of an endomyocardial biopsy. When the power spectra of those patients whose endomyocardial biopsies showed evidence of myocardial rejection were compared with those from patients who were found to be free of rejection, a significant difference was found in log total power (-0.602 +/- 0.090 0.525 vs. -0.909 +/- 0.136 0.577, p less than 0.02). We conclude that denervation of the heart significantly reduces heart rate variability and abolishes the discrete spectral peaks seen in untransplanted control subjects and that the development of allograft rejection may significantly increase heart rate variability.
Sands et al. (Sun,) conducted a observational in Orthotopic cardiac transplant (n=23). Cardiac transplantation (denervation) vs. Normal subjects was evaluated on Log total power in the 0.02-1.0 Hz range (p=<0.0001). Cardiac transplantation significantly reduced heart rate variability compared to normal subjects (log total power -0.766 vs 0.982; p<0.0001), whereas allograft rejection increased it (p<0.02).