[The use of the average activity contained in the circular areas of interest on the polar map in identifying affected coronary arteries].

Introduction And Objectives: We studied the feasibility to identify coronary lesions of the average regional activity obtained by regions of interest displayed on the three main coronary territories from the polar map (left anterior descending artery, circumflex and right coronary artery).

Methods: In 125 patients with angiographic diagnosis of coronary artery disease, were made tomographic studies with technetium-99m isonitrile to analyze the average regional activity, in rest and stress.

Results: According to the stepwise logistic regression test, the stress average regional activity is significant and independent correlated with the stenosis rate (r = -0.60, -0.67 and -0.67 for left anterior descending artery, right coronary artery and circumflex). The thresholds values of the stress average regional activity (percentage of peak activity) with the best assessment of the significant lesions (> 70%) are: less than 70% for left anterior descending artery and circumflex, and less than 60% for the right coronary artery. Using those diagnostic criteria, this quantitative method has a high diagnostic accuracy: Sensitivity/specificity to identify significant lesion of: 0.86/0.93 for left anterior descending artery, 0.85/0.83 for right coronary artery and 0.80/0.90 for circumflex. Significant coincidence with the angiographic diagnosis of the number of diseased vessels (Kappa coefficient 9.62).

Conclusion: The assessment of the stress average regional activity by circular regions of interest is an easy method, with a high diagnostic accuracy to identify diseased coronary arteries.