Comparison of electrocardiographic and left ventricular functional changes during exercise.

The diagnostic accuracy of the Bruce multistage exercise treadmill test (ETT) and changes in left ventricular function assessed by radionuclide angiocardiography (RNA) during rest and maximal exercise were compared in 72 patients who underwent coronary arteriography for evaluation of chest pain. Significant coronary artery disease was defined as a 75% or greater stenosis of the diameter of any of the three major cor- onary arteries. The coronary arteriographic results were used to categorize each patient according to the number of vessels with a significant lesion. As a result, 15 patients had insignificant disease and 57 had significant lesions of one or more coronary arteries. ETT results were defined as positive if ST-segment changes oc- curred with exercise, negative if ST-segment changes did not occur at target heart rate, and indeterminate if ST-segment abnormalities existed at rest or if no ST-segment changes developed at a heart rate below the target heart rate. Abnormal changes in left ventricular function by RNA were an exercise-induced wall motion abnormality, a less than 5% increase in ejection fraction, and a greater than 25% increase in end-diastolic volume and an increase in end-systolic volume with exercise.