[Differences in left ventricular systolic performance during exercise in patients with hypertrophic cardiomyopathy and systemic hypertension].

To evaluate differences in systolic global and regional performances of the left ventricle during exercise, multi-stage submaximal exercise echocardiography was used for 21 patients with hypertrophic cardiomyopathy (HCM) and 14 patients with systemic hypertension (HT), whose interventricular septa (IVS) were nearly the same in thickness (HCM; 16.5 +/- 2.4 mm, HT; 15.4 +/- 1.7 mm, NS). The data were compared with those of 18 normal subjects (N). During exercise, end-diastolic dimension (EDD) was increased in all three groups; however, there was no statistical differences among the three groups either at rest or during exercise. End-systolic dimension (ESD) was significantly decreased during exercise in HT (29.3 +/- 5.8 at rest to 28.1 +/- 5.8 mm at the peak exercise, p less than 0.05) and N (from 30.3 +/- 3.3 to 25.7 +/- 3.0 mm, p less than 0.001). On the other hand, ESD of HCM at rest, which was less than those of the other two groups, did not decrease with exercise (from 25.1 +/- 4.5 to 25.6 +/- 4.6 mm, NS), and rather they increased (more than 2 mm) during exercise in seven patients. The % shortening fraction (%SF) increased from rest to exercise both in HT (35.6 +/- 7.9% to 40.1 +/- 9.6%, p less than 0.001) and in N (from 35.1 +/- 4.2 to 45.9 +/- 4.7%, p less than 0.001). However, in the HCM group, the %SF, which was significantly greater at rest than in the other two groups, did not increase during exercise (42.5 +/- 6.8 to 42.5 +/- 8.8%, NS). In addition, in seven of 21 patients with HCM, the %SF increased more than 5% at the peak exercise. At rest, systolic wall thickening (%WT) of the IVS equally reduced both in HCM and HT. It increased in HT from 20.8 +/- 9.3% at rest to 24.6 +/- 12.7% at the peak exercise (p less than 0.05), but did not change in HCM (from 16.6 +/- 9.6% to 16.3 +/- 7.0%, NS). At rest, %WT of the left ventricular posterior wall (LVPW) was significantly greater in HCM than in HT. During exercise, it increased in HT (from 43.1 +/- 15.9% to 61.9 +/- 20.5%, p less than 0.01), but did not increase in HCM (from 81.0 +/- 27.7% to 85.5 +/- 29.6%, NS).(ABSTRACT TRUNCATED AT 400 WORDS)