Maximum stress-volume index ratio of the left ventricle in hypertrophic cardiomyopathy.

To evaluate the left ventricular contractile state in patients with nonobstructive hypertrophic cardiomyopathy (HCM), we analyzed the maximum stress-volume index ratio (MSVR) using catheter-tip cineangiography in 11 patients with HCM and 16 normal subjects. The value of the MSVR in normal subjects was 6.48 +/- 1.25 kdyn/cm5/m2 (mean +/- SD) and we defined the range of the mean +/- 2 SD as the normal MSVR range. Six patients with HCM placed inside the normal MSVR range (IN), but the other 5 patients placed outside and to the right of the normal range (RIGHT). This suggests that the contractile states of the patients of the RIGHT group were depressed. Compared with IN, the end-diastolic and end-systolic volume indices of RIGHT were larger (EDVI; 69.3 +/- 6.9 vs. 96.1 +/- 11.1 ml/m2, p less than 0.01, ESVI; 18.2 +/- 3.2 vs. 29.1 +/- 8.3 ml/m2, p less than 0.05), but the ejection fraction did not differ (IN 73.5 +/- 5.7 vs. RIGHT 69.6 +/- 8.3%, NS). End-diastolic pressure of IN and RIGHT was higher than that of normal subjects (IN 16.5 +/- 4.5, RIGHT 16.7 +/- 4.6 vs. 8.3 +/- 2.5 mm Hg, both p less than 0.05), but there was no difference between the two groups in HCM. End-systolic pressure did not differ among the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)