To determine whether administration of nitroglycerin (NTG) and computer-aided image analysis applied 3 hr after exercise (ex) can provide data equivalent to those available from redistribution (R) imaging 24 hr post-ex, 3 hr and 24 hr post-ex imaging with and without NTG were employed to study 15 pts with 37 coronary artery territories which were abnormal post-ex. In the 3 hr R images after NTG, 19/37 territories showed R, while only 12 were identified in the absence of NTG (p=.07); at 24 hr post-ex, 24/37 territories had R with NTG vs 13 without (p