What physiological feature characterizes the conduction in a heterotrophic heart transplant?

What physiological feature characterizes the conduction in a heterotrophic heart transplant?

• A. Two independent pacemaker activities
• B. A single lead connecting both hearts
• C. Dominance of the patient’s native heart
• D. Increased heart rate variability

Answer: (A)

In a heterotrophic heart transplant, where a donor heart is transplanted into a recipient's body while the recipient's heart remains, the physiological feature that characterizes the conduction is the presence of two independent pacemaker activities. Each heart can retain its own intrinsic pacing mechanism: the recipient's native heart continues to beat, and the transplanted donor heart has its own pacemaker cells. This situation leads to both hearts generating electrical impulses independently, creating a unique circumstance in cardiac conduction.

The independent pacemaker activities can lead to varying rates of contraction and potentially influence heart rhythm. Since each heart operates with its own dominance, this arrangement does not see one heart completely taking over the conduction system. Understanding this concept is crucial for managing the post-transplant care of a patient, as both hearts may need to be monitored and managed distinctly in terms of rate control and arrhythmia management.