Although echocardiography is sensitive in detecting genetically determined idiopathic hypertrophic subaortic stenosis with the two major criteria of systolic anterior motion of the mitral valve and asymmetric septal hypertrophy, the predictive value of these findings in a nonselected population remains uncertain. A study was made of nine consecutive patients with an echocardiographic diagnosis of idiopathic hypertrophic subaortic stenosis who underwent autopsy between 1975 and 1979. The patients ranged in age from 1 month to 74 years (average 53), and six were women. Seven had systolic anterior motion of the mitral valve, and one pseudo systolic anterior motion, eight had asymmetric septal hypertrophy, and three had mid systolic aortic valve closure. All nine had a systolic murmur at the cardiac apex and an abnormal electrocardiogram. At autopsy only two patients had asymmetric septal hypertrophy and myocardial fiber disarray; the other seven had no evidence of hypertrophic Cardiomyopathy on gross examination or light microscopy. Of these seven, two had concentric left ventricular hypertrophy, one coronary atherosclerosis, one cardiac amyloidosis, and three no cardiac disease. These data suggest that systolic anterior motion of the mitral valve and asymmetric septal hypertrophy may be sensitive but are poorly predictive of idiopathic hypertrophic subaortic stenosis in the general hospital population. Because these two findings may be observed even in patients with a normal heart, an echocardiographic diagnosis of idiopathic hypertrophic subaortic stenosis based on these criteria should be made with caution.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine