I once had a job in a heart hospital. Clinical research has studied the nerve connections between the heart and the body in patients who have received a new heart.
I maintained and adapted to new requirements the RR-VAR software package developed by the Science and Research Department for the acquisition of measurement data and the analysis of various time series of ECG and blood pressure.
=> Reinnervation of the Transplanted Human Heart
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ÜBERFUHR, Peter, FREY, Axel W and REICHART, Bruno, 2000. Vagal reinnervation in the long term after orthotopic heart transplantation. The Journal of Heart and Lung Transplantation. 1 October 2000. Vol. 19, no. 10, p. 946–950. DOI 10.1016/S1053-2498(00)00181-9. [Accessed 26 July 2024].
Background Sympathetic reinnervation after orthotopic heart transplantation (HTx) has become an accepted phenomenon, particularly in long-term transplanted patients. Parasympathetic reinnervation, however, still remains questionable. Methods In 38 HTx recipients, mean age of 51.6 ± 9.7 years (range, 29 to 70 years), with a time span after HTx of 4.6 ± 2.8 years (0.5 to 10.5 years), we stimulated carotid baroreceptors using periodic neck suction at low (0.1 Hz) and high (0.2 Hz) frequencies to test sympathetic and vagal responses, respectively. Respiratory rate was fixed at 0.25 Hz. We simultaneously recorded surface electrocardiogram, finger blood pressure, respiration and neck pressure signals while patients rested in the supine position. Time series of RR intervals, respiration, and neck and blood pressures were generated and subjected to spectral analysis. Results All patients demonstrated a 0.25-Hz peak in RR-interval spectrum, caused by non-autonomic respiratory sinus arrhythmia. Thirteen patients (5.2 ± 3.5 years after HTx; range, 0.9 to 10.2 years) showed a baroreflex-induced sharp peak at 0.1 Hz in RR-interval power spectrum during 0.1-Hz neck suction, indicating sympathetic reinnervation. However at 0.2-Hz neck suction, 4 of the 13 sympathetically reinnervated patients displayed a baroreflex-induced 0.2-Hz peak, which could be suppressed with atropine administration—strong evidence for vagal reinnervation. Conclusions Non-invasive carotid baroreflex stimulation is an appropriate tool to prove restoration of autonomic control after orthotopic HTx. Sympathetic reinnervation parallels parasympathetic reinnervation in long-term transplanted patients.