Diagnosis and treatment of obstruction of a tricuspid Björk-Shiley prosthesis.

Obstruction of a tricuspid Björk-Shiley prosthesis was diagnosed in 7 patients, caused by thrombus formation in 6, and tissue overgrowth in one. In 5 patients in whom the tilting disc had a ring shaped radiopaque marker, cineradiographic studies revealed incomplete opening (less than 60 degrees) and or closure of the prosthetic valve disc. In six patients the most reliable phonocardiographic signs were the presence of a delayed and prolonged diastolic mid-frequency rumble at the third left intercostal space, increasing on inspiration, and the absence of the opening sound of the tricuspid prosthetic valve. In 5 patients the M mode echocardiographic pattern of diastolic motion of the obstructed valve disc was very characteristic and showed a delayed and rounded upstroke and downstroke, and a reduced amplitude of diastolic excursion of the valve disc. In one patient in whom parasternal M mode echocardiography did not identify the obstructed valve, valve obstruction was clearly demonstrated by bidimensional echocardiography from the apical four chamber view. It is concluded that echocardiography is a useful tool for the diagnosis of tricuspid prosthetic valve obstruction, especially when the valve disc has no ring chaped radiopaque marker. Four patients were treated with streptokinase. This treatment was successful in 3 patients, but failed in the patient in whom the tricuspid valve obstruction was caused by tissue overgrowth. We recommend fibrinolytic therapy before surgical reintervention.