Heart transplantation has become an established treatment for end-stage heart disease. However, the shortage of donor organs is a major problem and long-term results are limited by allograft rejection. Heart rate variability (HRV) has emerged as a popular noninvasive research tool in cardiology. Analysis of HRV is regarded as a valid technique to assess the sympathovagal balance of the heart. The primary goal of this study was to investigate the relevance of heart rate variability changes after heart transplantation. It was found that spectral analysis of HRV is useful in detecting rejection episodes. Heart transplantation leaves the donor heart denervated. Spectral analysis of HRV was found appropriate to detect functional autonomous reinnervation. Extensive literature review was done to validate the findings.

The paper is divided into two parts. The first part of the paper deals mainly with the techniques and current status of heart transplantation. The second part, deals with the relevance of heart rate variability and reinnervation after heart transplantation. The results of the study suggest that heart rate variability analysis is a valuable tool in assessing the cardiovascular status after heart transplantation.