[Two-dimensional and Doppler echocardiographic studies of the genesis of a high-pitched diastolic rumble in mitral stenosis: contribution of the deformed mitral orifice and eccentric mitral inflow jet].

To clarify the genesis of a high-pitched diastolic rumble in mitral stenosis, 51 patients with mitral stenosis were studied. They were subdivided into two groups based on the pitch of a rumble; six patients with a high-pitched rumble and 45 patients with an ordinary low-pitched rumble. Phonocardiography, and M-mode and two-dimensional (2-D) echocardiography were performed in all patients. Color and continuous wave Doppler echocardiography were performed in four patients with a high-pitched rumble and in 13 with a low-pitched rumble. Results obtained were as follows: 1. Points of the maximum intensity of a rumble: A low-pitched rumble was best heard at the apex in all patients. A high-pitched rumble was best heard at the mesoapical area, except in one patient who had an oval mitral orifice by 2-D echocardiography. 2. Correlation between the pitch of rumble and the shape of the mitral orifice: In five of the six patients with a high-pitched rumble, the mitral orifice had a tadpole-shaped deformity, in which commissural fusion and valvular thickening were more marked anterolaterally than posteromedially. Among 45 patients with oval, slit or pinhole-like valve orifices, only one had a high-pitched rumble. 3. Direction of the left ventricular (LV) inflow jet as observed by color Doppler echocardiography: On the short-axis view at the level of the papillary muscles, the inflow jet was directed toward the medial portion of the LV cavity in the patients with a high-pitched rumble. However, it was directed towards the central portion of the LV cavity in all patients with a low-pitched rumble. On the apical long-axis view, no distinct difference was detected in the direction of the LV inflow jet between the two groups. 4. Other findings: There were no significant differences between the two groups in the mitral orifice area, the peak velocity of LV inflow, fractional shortening of the LV, dimension of the left atrium, Wells' index and the degree of organic change in the subvalvular structures. These results suggest that the deformity of the mitral valve and resultant changes in the direction of the LV inflow jet may play an important role in the mechanism of producing a high-pitched diastolic rumble in mitral stenosis.