Ultrasound localization of left ventricular outflow obstruction in hypertrophic obstructive cardiomyopathy.

Simultaneous recordings of reflected ultrasound from the anterior mitral leaflet and left ventricular outflow, the ECG, the phonocardiogram, and a recording of the carotid artery pulse were obtained in six patients with hypertrophic obstructive cardiomyopathy. Abnormal sharp systolic anterior movement (SAM) of the mitral leaflet was observed. This movement began with the onset of ventricular ejection and reached a peak with the initial peak in the arterial pulse. The leaflet was apposed to the interventricular septum up to 60% of the ejection period. In the latter part of systole as the mitral leaflet moved away from the interventricular septum, the arterial pulse showed