Angina in idiopathic hypertrophic subaortic stenosis. A clinical correlate of regional left ventricular dysfunction: a videometric and echocardiographic study.

Angina, dyspnea and syncope often occur in idiopathic hypertrophic subaortic stenosis (IHSS), but have not hitherto been correlated with conventional measures of left ventricular (LV) function. We assessed regional and global LV function in 18 patients with IHSS by roentgen videometric analysis of biplane left ventriculograms and M–mode echocardiography to investigate 1) whether any relationship could be demonstrated between symptoms and global or regional LV function, and 2) how normal or supernormal global function could be maintained in the presence of severe septal hypokinesis. Syncope occurred in four patients with IHSS, angina in seven and dyspnea in 11. No correlation was demonstrable between any symptom and any measure of global LV function, or between syncope and dyspnea and regional LV function. However, a correlation was shown between angina and regional function in that peak rates of systolic thickening and diastolic thinning of the anterior LV wall in these patients were significantly (p < 0.01) less than in patients without angina. In view of the documented relationship between myocardial ischemia and regional wall dynamics, we conclude that angina in IHSS in the absence of coronary artery disease is strongly associated with impaired wall dynamics, although which is cause and which is effect is unresolved. Angina may therefore be useful as an indicator of regional LV dysfunction. Furthermore, the normal pump function is maintained by increased cavity emptying.