Left ventricular response to graded isometric exercise in patients with coronary heart disease.

The effects of graded isometric exercise on left ventricular performance were characterized in 11 male patients (53 +/- 2 years) with coronary artery disease (CAD) and in 12 normal subjects (11 male and one female 35 +/- 5 years). The echocardiographic indices of left ventricular function at rest were similar in both groups. Heart rate and blood pressure increased significantly in both groups in response to 40 and 60% of handgrip maximal voluntary contraction (MVC). Left ventricular end-diastolic dimension increased significantly (from 50 +/- 1 to 56 +/- 1 mm; P less than 0.01) with 60% of MVC in CAD group but not in the healthy subjects. The patients with CAD also exhibited significant (P less than 0.01) increases in end-systolic dimension (from 34 +/- 1 to 40 +/- 2 with 40% and to 44 +/- 1 mm with 60% MVC). End-diastolic and end-systolic dimensions did not change during isometric exercise in the healthy subjects. In the CAD group mVCF decreased significantly (from 1.08 +/- 0.06 to 0.86 +/- 0.06 with 40% and to 0.74 +/- 0.04 d . s-1 with 60% MVC; P less than 0.01). At comparable mean blood pressures, mVCF was significantly lower in the CAD group than in normal subjects. These results demonstrate that progressive deterioration of left ventricular function during increasing levels of isometric exercise in patients with CAD can be detected with echocardiography.