Systolic dysfunction and blood pressure responses to supine exercise in patients with hypertrophic cardiomyopathy

Left ventricular function and blood pressure responses were evaluated in 56 patients with non-obstructive hypertrophic cardiomyopathy (HCM) and 12 con trol subjects by using a radionuclide ventricular function monitor during s upine ergometer exercise. Patients with HCM were divided into 2 groups: (i) group A had no decrease in ejection fraction (EF) during exercise; and (ii ) group B had a decrease in EF during exercise. During exercise, the change in end-diastolic volume did not differ between the 3 groups. In contrast, the change in end-systolic volume differed between the 3 groups (p<0.0001), The change in systolic blood pressure (SBP) also differed significantly be tween the 3 groups. The change in SEP in group B was smaller than that in t he control group and group A, and changes in the EF and changes in the SEP between rest and peak exercise showed a significant correlation (p<0.005), These results suggest that exercise induced systolic dysfunction in patient s with non-obstructive HCM may contribute to abnormal blood pressure respon se in those patients.