Dynamic Left-Ventricular Tract Outflow Obstruction: A Late Complication of Mitral Valve Replacement

Abstract

The case presented is a 47-year-old woman with left-ventricular outflow tract obstruction which was the late complication of mitral valve replacement (4 years later). The diagnosis was made using two-dimensional Doppler echocardiography (echo-2D Doppler) and confirmed by cardiac catheterization. Protrusion of the prosthetic ring towards the intraventricular septum reducing the diameter of the outflow tract to 7-8 mm and creating a dynamic obstruction (30 mm Hg on cardiac catheterization, and 44 and 75 mm Hg on echo-2D Doppler basally and after isoamyl nitrite inhalation, respectively) was recorded. The echo-2D Doppler technique appears to be useful in detecting this postsurgical mitral complication.

Left-Ventricular Outflow Tract Obstruction by Mitral Valve Ring Calcification and Proximal Septal Hypertrophy in Elderly Patients

“…Critical narrowing of the LVOT related to the stiffness of the MVR is reported as early and (rarely) late complications of valve pros thesis implantations in the mitral position or of mitral valvuloplasties [2,3,6], On the other hand systolic anterior move ment of the anterior mitral leaflet is known to be a potential cause of LVOT obstruction [7], In patients with isolated MVR calcifica tion, LVOT obstructions are occasionally re ported [5], but in these subjects mitral valve stenosis or insufficiency are more often found [8].…”

“…The most frequent causes are anatomical: val vular, supra-and subvalvular stenosis, and/or obstructive hypertrophic cardiomyopathy Less frequent causes are a malfunctioning aortic valve prosthesis, defective mitral valve repair, vegetating or infiltrating tumors, false tendons implanted in the proximal portion of the interventricular septum and subvalvular thrombi [2][3][4], Massive calcification of the mitral valve ring (MVR), predominantly at the site of insertion of the anterior mitral leaflet, can give rise to functional outflow obstruction [5], especially when this alteration is combined with hypertrophy of the interventricular sep tum.…”