Ball variance in a Harken mitral prosthesis. Echocardiographic and phonocardiographic features.

A case of ball variance in a caged-ball prosthetic valve is presented, illustrating the echocardiographic and phonocardiographic features. The swollen silicone ball was observed on echocardiographic studies to have diminished motion and to incompletely open within its cage. On phonocardiographic studies, the Q-S1 interval was prolonged, and no opening sound could be recorded. These noninvasive techniques may be helpful in predicting the need for replacement of prosthetic valves that have silicone rubber balls.