Comparison of electrocardiographic and left ventricular functional changes during exercise.
Authors: G E Newman, S K Rerych, M T Upton, D C Sabiston, R H Jones
Journal: Circulation (1980)

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.RNA results were normal in 11 of 15 patients with insignificant disease and abnormal in four, all of whom had 50% lesions of a major coronary artery.In this group, ETT results were indeterminate in seven patients, negative in six and positive in two.In the 57 patients with significant coronary disease, RNA results were ab- norinal in 55 and normal in two.ETT results were indeterminate in 12 patients, negative in nine and positive in 36.RNA had a sensitivity of 97% and a specificity of 73% for the 72 patients.By comparison, ETT had a sen- sitivity of 80% and a specificity of 66% for the 53 patients with adequate studies.These results suggest that exercise-induced changes in left ventricular function defined by RNA have a greater diagnostic accuracy than the ST-segment response during ETT in the patient population studied.RADIONUCLIDE ANGIOCARDIOGRAPHY (RNA) is a simple, noninvasive technique that permits accurate assessment of left ventricular function during rest and exercise in patients with symptoms of cor- onary artery disease.During exercise, left ventricular ejection fraction increases in normal subjects, in con- trast to patients with coronary artery disease, in whom ejection fraction may decrease with exercise stress.'-3These exercise-induced abnormalities in ventricular function appear to reflect inadequate coronary blood flow resulting from coronary artery stenosis during periods of increased cardiac work.4The diagnostic im- portance and consistency of changes in left ventricular function from rest to exercise have not been examined in a large patient population with coronary artery stenosis evaluated by concomittant Bruce multistage exercise treadmill test (ETT) and cardiac catheterization.The purpose of this study was to evaluate the usefulness of radionuclide measurement of left ventricular function during rest and exercise in the initial assessment of patients with symptoms suggestive of coronary artery disease.