Normalization of the Heart Rate Response to Exercise 6 Months After Cardiac Transplantation

Early Denervation and Later Reinnervation of the Heart Following Cardiac Transplantation: A Review

“…Similar results were found comparing early HTx recipients to late denervated or reinnervated HTx recipients and control subjects . Of note, 96.3% of recipients had an abnormal HR response to exercise at 2 months post‐HTx, and 40.7% of the recipients showed a normalized HR response to exercise at 6 months post‐HTx, thus showing that cardiac reinnervation occurs over time, which is evident in the improved exercise capacity and HR response to exercise later post‐HTx …”

“…Therefore, cardiac denervation alters cardiovascular control in HTx recipients . It results in lower cardiac index (CI) and heart rate variability (HRV) or heart period variability (HPV), abnormal chronotropic response to exercise, abnormal catecholamine release and hemodynamic responses to exercise and tyramine injection, impaired exercise capacity and physical function, altered diastolic function of the ventricles, presynaptic inotropic supersensitivity and lower inotropic reserve, higher resting HR due to the lack of parasympathetic vagal efferent nerve connections, higher stroke volume (SV), temporary sinus node dysfunction, abnormal cardiopulmonary baroreflexes, depletion of cardiac norepinephrine (NE) within the nerve terminals, higher sensitivity to circulating endogenous CAT due to the lack of presynaptic neuronal uptake capacity which may increase the frequency of arrhythmias, and altered response to adrenergic drugs, which requires adjustments to pharmacotherapy in HTx recipients …”

“…Of note, the denervated heart shows a blunted increase in HR at exercise onset, a maximum HR in early recovery after peak exercise, and a plateau in HR after its peak . At onset of exercise, HR normally increases via sympathetic input in order to deliver blood to the body at a faster rate and then goes down following exercise in order to return the increased exercise HR to resting values .…”

Impact of basal heart rate on long-term prognosis of heart transplant patients

“…Based on this, the study's goal was to clarify if there is an association between higher HR and mortality in stable HTx patients. It has been widely studied and demonstrated that those patients receiving HTx show high basal HR values [15] and an abnormal response to exercise, mainly as a consequence of allograft denervation. Nevertheless, several studies have shown that, following transplantation, a considerable percentage of HTx patients recover chronotropic competence over time, as well as exercise capacity after some months [15,16].…”

Noninvasive Assessment of Autonomic Cardiovascular Function in Patients after Arterial Switch Operation for Transposition of the Great Arteries

“…Heart transplanted patients have an impaired heart rate response to exercise due to denervation [12]. However, partial sympathetic reinnervation has been reported after heart transplantation [13] [14].…”