Preoperative Diagnosis and Surgical Correction of Supravalvular Mitral Stenosis and Ventricular Septal Defect

Abstract

The first reported case of supravalvular mitral stenosis plus a ventricular septal defect correctly diagnosed prior to successful surgical repair is presented. This patient had a murmur and thrill characteristic of a ventricular septal defect. The clinical findings suggesting concomitant mitral stenosis consisted of a mitral mid-diastolic murmur which was unusually loud for the magnitude of the left to right shunt; apre-systolic component to the diastolic murmur; marked left atrial enlargement by x-ray with only moderate pulmonary plethora; and ecg evidence of left atrial hypertrophy and marked pure right ventricular hypertrophy. Right heart catheterization showed labile passive pulmonary hypertension. Left atrial puncture revealed a high proximal and low distal pressure. Since passive pulmonary artery hypertension decreases the systolic left ventricular to right ventricular pressure gradient in patients with this combination of lesions, the magnitude of the left to right shunt is smaller across a given size ventricular septal defect. Visualization of the defect by left ventricular angiocardiography was helpful in the preoperative assessment of the size of the ventricular defect. Surgical correction of both lesions by total cardiac bypass was accomplished through a midline sternal-splitting incision. The supravalvular mitral membrane was excised from the right atrium through an incision in the atrial septum.