Echocardiogram of the porcine aortic bioprosthesis in the mitral position

Echocardiography was performed in 10 consecutive patients who had a clinically normally functioning porcine aortic bioprosthesis in the mitral position. Strong well defined echoes were recorded from the anterior and posterior aspects of the xenograft stent. The maximal separation of the anterior and posterior stent echoes approximated the diameter of the stent at its base. The maximal excursion of the anterior stent was 5 to 10 mm (mean 7.5) with a mean systolic slope of 15 to 35 mm/sec (mean 22.2) and diastolic slope of 11 to 59 mm/sec (mean 21.5). In all 10 patients it was possible to record an anterior xenograft leaflet with anterior movement at the onset of diastole and posterior movement at the onset of systole and with appropriately steep (more than 200 mm/sec) slopes. The diastolic (E-F) slope of the anterior leaflet in 9 of the 10 patients ranged from 9 to 38 mm/sec (mean 19). In 6 of the 10 patients a posterior xenograft leaflet with a movement pattern symmetric with that of the anterior leaflet was recorded. In two patients, the central aortic leaflet was recorded with little diastolic displacement. These two patients also had mild aortic regurgitation, which was associated with diastolic shudder of the xenograft leaflets. Echocardiography was also performed in one patient who was later shown to have a 10 cm3 thrombus on the ventricular surface of a xenograft valve. The echocardiogram in this patient revealed the following abnormalities: (1) excessive anterior stent movement and systolic slope suggesting paravalvular leak in the presence of abnormal cinefluoroscopic valve tilt, and (2) multiple dense nonhomogeneous echoes between the anterior and posterior aspects of the valve stent, with an early diastolic clear space behind the anterior stent and abnormal echoes behind the posterior stent during systole. Echocardiography therefore appears to be useful in evaluating the porcine aortic bioprosthesis in the mitral position.