Provocation of left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy. Comparison of orthostasis testing and nitrate application.

Several provocation maneuvers are described in hypertrophic cardiomyopathy to Doppler echocardiographically distinguish the obstructive from the non obstructive type. No data are available about the value of orthostasis testing in comparison with nitrate application in this disease. In this study, 16 consecutive patients with hypertrophic cardiomyopathy were examined. 11 patients with hypertrophic cardiomyopathy were classified as obstructive, 5 patients with hypertrophic cardiomyopathy as non obstructive. Normal left ventricular outflow tract velocities as detected by the Doppler method were defined as < 2,0 m/s.