[Aortic regurgitation in hypertrophic cardiomyopathy as detected by color Doppler echocardiography].

Aortic regurgitation (AR) in patients with hypertrophic cardiomyopathy (HCM) has rarely been reported. Using color Doppler echocardiography, we assessed the incidence and the cause of AR in patients with HCM. There were 86 patients with HCM (M:F = 66: 20, 57 +/- 12 years, mean +/- SD) and 43 control subjects (M: F = 33: 10, 57 +/- 8 years). HCM was diagnosed by echocardiography; the thickness of the interventricular septum (IVS) was more than 15 mm and the ratio to the thickness of the left ventricular free wall (LVPW) was more than 1.3. The rate and degree of aortic regurgitation were observed by color Doppler echocardiography, and aortic regurgitant murmurs were recorded by phonocardiography. Echocardiographic measurements were made using standard techniques. In the M-mode echocardiograms, the aortic diameter, the thicknesses of the IVS and LVPW were measured. In the 2DE, calcification of the aortic valve and systolic anterior movement of the mitral valve (SAM) were evaluated. In the early systolic 2DE image, the distance from the point of the greatest bulging of the upper IVS to the aortic root (D1) and the distance from the point of the greatest bulging to the line which is parallel to the long axis of the aorta (D2) were measured. Results were as follows: 1. Color Doppler echocardiography revealed aortic regurgitation in 17 (21%) patients with HCM; whereas it was observed in only three (7%) of the control subjects. 2. The aortic regurgitant signals were limited to the left ventricular outflow tract both in patients with HCM and in the control subjects. 3. Aortic regurgitant murmurs were recorded in only two patients with HCM and in none of the control subjects. 4. There was no difference between the patients with and without AR as to age (59 vs 56 years), blood pressure (141/84 vs 136/80 mmHg), aortic diameter (34 vs 33 mm), aortic valve calcification (12% vs 9%) and SAM (53% vs 52%). 5. In the patients with HCM, D1 was shorter (9.9 vs 14 mm, p less than 0.001) and D2 was longer (16 vs 10 mm, p less than 0.001) in the patients with AR than in those without AR. That is, the basal septum of the patients with AR protruded more deeply into the outflow tract, and the distance to the aortic valve was significantly shorter than in those without AR.(ABSTRACT TRUNCATED AT 400 WORDS)