Left Ventricular Outflow Tract Obstruction Following Mitral Valve Replacement with Carpentier‐Edwards Prosthesis

Abstract

Left ventricular outflow tract (LVOT) obstruction is a rare complication of mitral valve replacement. In this article, we describe three patients in whom left ventricular outflow tract obstruction occurred following Carpentier‐Edwards porcine mitral valve replacement. All three patients presented with symptomatic mitral regurgitation (angiographic grade 3–4) requiring mitral valve replacement. Preoperatively there was no evidence of hypertrophic obstructive cardiomyopathy by physical exam, echocardiography, or by cardiac catheterization. At the time of surgery all three were shown to have severe mitral valve prolapse. The native anterior mitral leaflet was left intact and pledgeted to the mitral annulus. Following surgery a new systolic murmur was appreciated. Echocardiographic exam visualized obstruction of the left ventricular outflow tract by the prosthetic strut in two cases and by a flail anterior leaflet in one case. Continuous‐wave Doppler measured a calculated peak gradient of 72 to 81 mmHg across the left ventricular outflow tract. In one case simultaneous Doppler and cardiac catheterization confirmed the diagnosis and severity of left ventricular outflow tract obstruction. Mechanisms of left ventricular outflow tract obstruction following Carpentier‐Edwards porcine mitral valve replacement are discussed. These three cases highlight the importance of echo‐Doppler techniques in understanding the mechanism of newly detected systolic murmurs following mitral valve replacement.