Interdependent extrasystoles in a patient with a biventricular bypass heterotopic cardiac homograft.

This report describes the induction of atrial extrasystoles in the donor heart by preceding ventricular extrasystoles in the recipient heart of a patient with a biventricular bypass heterotopic cardiac homograft. Timing of the ventricular extrasystoles of the recipient heart in relationship to the preceding donor heart systole was critical to the production of donor heart atrial extrasystoles. The mechanism is thought to be a mechanical one resulting from an acute pressure rise in the atrium of the donor heart due to increased mitral regurgitation from the recipient heart resulting from the ventricular extrasystoles.