What is a hallmark of heart transplant rejection related to exercise?

Decreased exercise tolerance is a hallmark of heart transplant rejection because the body's immune response to the transplant can impair cardiac function. When the heart is rejected, there may be a reduction in the organ's ability to effectively pump blood, leading to symptoms such as fatigue and shortness of breath during physical activity. This reduced ability to sustain exercise is a critical indicator for clinicians monitoring transplant recipients, as it can signal potential rejection or other complications.

In contrast, increased exercise capacity, stable exercise performance, and improved recovery time would generally indicate better heart function and patient conditioning, which are not typically associated with rejection episodes. Monitoring exercise tolerance allows healthcare providers to assess the health of the transplanted heart and intervene promptly if rejection is suspected.