[Two-dimensional echocardiographic findings during syncopal attack due to obstruction in the outflow tract of the left ventricle in a patient with hypertrophic obstructive cardiomyopathy (author's transl)].

The two-dimensional echocardiogram was successfully obtained during syncopal attack due to obstruction in the outflow tract of the left ventricle in a 52 years old male with hypertrophic obstructive cardiomyopathy (HOCM). The diagnosis of HOCM was confirmed by cardiac catheterization which revealed a pressure gradient of 65 mmHg in the outflow tract of the left ventricle during intravenous infusion of isoproterenol (2 micrograms/min). During the test, the patient developed convulsion as well as syncopal attack. The two-dimensional echocardiogram demonstrated a marked protrusion followed by a fixation of the whole mitral complex (SAM component) toward the hypertrophied interventricular septum throughout whole cardiac cycles. Although the mechanism of this phenomenon is not clear, it can be speculated that an abnormally sustained excitation and contraction of the papillary muscles (just like a muscle cramp) may be induced, resulting in the left ventricular outflow tract obstruction.