Left ventricular volume response to exercise in normal and coronary artery disease patients

The left ventricular (LV) volume response to supine exercise (EX) was studied in 15 normal volunteers (mean age 44, asymptomatic, with normal resting ECG and treadmill stress test) and 28 coronary artery disease patients (CAD, documented by cardiac catheterization) with no previous myocardial infarction. Each individual underwent stress gated equilibrium radionuclide angiography (RNA) and was on no medication. A nongeometric count based LV volume programme developed in our laboratory (correlation to biplane cineangiography R = .98), was used to calculate end diastolic volume index (EDI), end systolic volume index (ESI), stroke volume index (SVI), cardiac index (CI), and ejection fraction (EF). In normal individuals, end diastolic volume did not change from rest to exercise, while end systolic volume decreased by an average of 16%. In the patients with coronary artery disease, however, both end diastolic volume and end systolic volume increased (14% and 15% respectively). Furthermore, our preliminary data suggest that the extent of the changes may be dependent upon the extent of the underlying CAD. While all the CAD patients had an increase in their end diastolic volumes, there was no change in the end systolic volume in those with single vessel disease, an 11% increase in patients with double vessel disease and a 19% in patients with triple vessel disease.