Effects of percutaneous balloon mitral valvotomy on pulmonary venous flow in severe mitral stenosis

Abstract

Pulsed Doppler Echocardiography has revealed that normal pulmonary venous flow consists of systolic and diastolic phases, which are equal in size and velocity. Systolic flow occurs when the mitral valve is closed, the left atrium is relaxed and the mitral annulus is descending toward the apex. The second component occurs in diastole when the mitral leaflets open and allow blood to enter the left ventricle. 1 The biphasic flow may be disturbed in certain pathologic states. For instance, in dilated cardiomyopathy, mitral annulus motion subject to the degree of systolic dysfunction, may be markedly reduced. There is, consequently, a reduction or absence of the systolic phase of pulmonary venous flow. 1,2 Mitral stenosis due to rheumatic heart disease also results in marked reduction in the mobility of the mitral valve apparatus and leaflets. Moreover, there is considerable fusion of the commissures. 3 Percutaneous balloon mitral valvotomy (PBMV) has rapidly emerged as an alternative to surgical valvotomy in patients with mitral stenosis. 4 Successful PBMV results in rapid reduction of left atrial pressure and transmitral gradient, with significant increase in mitral valve area. There have been no reports demonstrating alteration in pulmonary venous flow with acute reduction in left atrial pressure after PBMV in mitral stenosis. 5 This study was designed to investigate alterations in pulmonary venous flow, using transesophageal echocardiography (TEE) after PBMV in patients with severe mitral stenosis.