Prospective comparison of exercise digital subtraction and exercise first pass radionuclide ventriculography

In order to test the comparative sensitivities of first-pass radionuclide and digital subtraction ventriculography in detecting wall motion abnormalities during exercise, 29 patients referred for coronary angiography were submitted to both types of stress ventriculograms. Resting and exercise ventriculograms by both techniques were reviewed by independent observers and the five equal ventricular wall segments were graded as normal, mildly, moderately, severely hypokinetic, akinetic, or dyskinetic. Of the 29 patients, 24 had arteriographically defined ischemic potential (at least greater than 50% obstruction of a major coronary artery supplying viable myocardium). Exercise digital subtraction ventriculography correctly identified 17 (71%) of these by a worsening of wall motion during exercise, while radionuclide ventriculography identified only eight (33%) by the wall motion response. When either a worsening of wall motion or the failure to increase ejection fraction by at least 5 points were used as criteria for an abnormal test, the sensitivities of digital and radionuclide ventriculographies were 96% and 79%, respectively. Though the number of patients without ischemic potential (5 patients) was too small to judge the relative specificities, digital subtraction ventriculography appears to be more sensitive than radionuclide ventriculography in identifying exercise-induced wall motion abnormalities and in predicting coronary occlusions.