[Aortic and mitral valve bioprostheses. Normal and pathological M mode echocardiographic aspects]

The M mode echocardiographic recordings of 52 normal mitral bioprostheses (NMB), 7 pathological mitral bioprostheses (PMB), 30 normal aortic bioprostheses (NAB) and 10 pathological aortic bioprostheses (PAB) were reviewed. In normal bioprostheses a significant correlation was observed between the echocardiographic and the "specified" diameters, the diastolic and systolic slopes and the amplitude of anterior motion of the support. In NMB, the end-systolic diameter of the left ventricular outflow tract depended on the "specified" diameter of the bioprosthesis. Paradoxical septal motion was observed in 78 p. 100 of cases. In PMB, the velocity of anterior leaflet opening was significantly increased (p less than 0.001). The end-diastolic internal left ventricular dimension was also increased (p less than 0.01). A significant correlation was found between left ventricular fractional shortening and maximal leaflet separation (p less than 0.05). Normal septal motion was more common (p less than 0.05). In 5 cases of prosthetic valve dysfunction with mitral regurgitation the maximal leaflet separation was greater than normal (p less than 0.001), the diastolic slope of the support was increased (p less than 0.05) and diastolic vibrations of thickened irregular leaflets were observed. Systolo-diastolic vibrations with chaotic leaflet motion were characteristic of cusp tear and/or eversion. Stratified echos behind a support with reduced leaflet excursion was observed in one case of partial thrombosis: a thickened systolic echo with reduced diastolic excursion was observed in a case of degenerative stenosis. The review of 10 PAB showed a reduced amplitude of systolic excursion of the anterior support in cases of aortic regurgitation (p less than 0.05). Systolic vibrations of the cusp were not specific and were observed in normal cases. In severe valvular regurgitation mitral and/or septal diastolic fluttering was observed. Systolic excursion of the cusps was reduced in cases of relative stenosis due to an inappropriately small sized bioprosthesis. Thickening of the diastolic cusp echos was observed in cases of degenerative stenosis. Ventricular dilatation and reduced septal and free wall motion were dysfunction.