Usefulness of real-time three-dimensional echocardiography for evaluation of myectomy in patients with hypertrophic cardiomyopathy.

Real-time 3-dimensional echocardiography was performed in 10 patients with obstructive hypertrophic cardiomyopathy (HC) before and after myectomy and in 6 controls. The exact location of systolic anterior motion of the mitral leaflet was shown in all patients with HC with a predominant involvement of the medial portion in 4 patients and the middle portion in 6 patients. The smallest area of the left ventricular outflow tract was significantly smaller in patients with HC than in controls (1.4 +/- 0.7 vs 5.1 +/- 1.2 cm(2), p <0.01), significantly increased after myectomy (4.8 +/- 1.8 cm2, p <0.01) and was associated with a reduction of the pressure gradient at rest from 63 +/- 41 to 15 +/- 5 mm Hg (p <0.01).