THERAPY AND PREVENTION HYPERTROPHIC CARDIOMYOPATHY

Morphologic determinants of hemodynamic state after ventricular septal myotomy-myectomy in patients with obstructive hypertrophic cardiomyopathy: M mode and two-dimensional echocardiographic assessment PAOLO SPIRITO, M.D., * BARRY J. MARON, M.D., AND DOUGLAS R. RosING, M.D. ABSTRACT To define the morphologic features of the left ventricle after ventricular septal myot-omy-myectomy and to elucidate the structural changes associated with a postoperative reduction in the pressure gradient, 28 patients with obstructive hypertrophic cardiomyopathy were studied with M mode and qualitative and quantitative two-dimensional echocardiography. Nine patients with a marked reduction in the pressure gradient (no or small,.25 mm Hg, residual basal gradient) demonstrated a marked reduction in septal thickness after surgery (23 + 6 to 13 + 4 mm; p <.01), a concomitant increase in septal to mitral valve distance (20 + 2 to 30 5 mm; p <.005), and a loss or substantial decrease in the magnitude of systolic anterior motion of the mitral valve. Two-dimensional echocardio-graphic results demonstrated an increase of over 100 % in the cross-sectional area of the left ventricula