Phonocardiographic manifestations of heterograft valve dysfunction in the mitral area

Doppler echocardiographic evaluation of patients with porcine mitral valves

The application of Doppler echocardiography to the study of valvular function has recently been extended to include prosthetic valves. We have used Doppler echocardiography to evaluate 40 patients with porcine mitral valves (PMV) implanted 0.5 to 99 months prior to examination. Three parameters of PMV flow were assessed: maximum diastolic left ventricular inflow velocity (Vmax), pressure half-time (P1/2t), and presence or absence of mitral regurgitation (MR). Normally functioning PMV (n = 29) were characterized by Vmax less than or equal to 180 cm/sec and P1/2t less than or equal to 160 msec. Within this group, P1/2t was not correlated significantly with the age of the patient nor with prosthesis size. Doppler correctly identified all 10 patients with MR. Among these 10 patients, Vmax was 206 +/- 53 cm/sec, significantly higher than the mean observed in normally functioning prostheses (136 +/- 24 cm/sec, p less than 0.001). In eight patients with stenosis of the PMV, mean P1/2t was 220 +/- 63 msec, and in seven of eight, it was greater than or equal to 180 msec (p less than 0.001 compared to normals). We conclude that: (1) Vmax less than or equal to 180 cm/sec, P1/2t less than or equal to 160 msec, and absence of systolic turbulence in the left atrium characterize normally functioning PMV; (2) P1/2t greater than or equal to 180 msec identifies patients with stenosis of the PMV; and (3) Doppler echocardiography can detect MR and separate mitral from tricuspid regurgitation.

Persistence of the third heart sound after resection of the native mitral and tricuspid valves. Evidence against the valvular theory of third sound origin

A patient is described with severe rheumatic mitral and tricuspid insufficiency in whom both atrioventricular valves with their chordae tendineae and papillary muscles were resected and replaced with Hancock porcine grafts. This would appear to be the second such patient reported and the first described in detail in whom the third heart sound persisted postoperation. This occurrence documents the fact that a third heart sound can occur in the absence of native atrioventricular valve leaflets and the major portions of the subvalvular supporting apparatus, and argues against the theory that the third heart sound is generated by either the valvular leaflets of the subvalvular apparatus.