Diagnosis of Coronary Artery Disease with Tc 99m-Methoxy Isobutil Isonitrile and Transesophageal Pacing

Recently the use of a new radioactive agent with physical and biological properties more favorable than those of thallium 201, methoxy-isobutyl-isoni tryl (MIBI) labeled with technetium 99m (Tc 99m), has permitted simultaneous performance of perfusion and function studies in ischemic cardiopathy. Transe sophageal atrial pacing (TAP) technique has evolved as an alternative provoca tive test of ischemia. The authors compared the capability of Tc 99m-MIBI myocardial scintigraphy, combined with TAP, with that of Tc 99m-MIBI, com bined with maximal stress test, in the diagnosis of ischemic cardiopathy. They studied 11 patients with a clinical history of angina pectoris. Myocardial scinti graphy was performed at rest, after stress test, and after TAR Finally, all the patients underwent coronary angiography. The analysis of myocardial perfu sion images on both Tc 99m-MIBI associated with TAP and with stress demon strated, in 165 myocardial segments examined: 143 normal, 20 reversible de fects, 2 irreversible defects. The concordance of localization between corono graphic data and scintigraphic reversible and irreversible defects was 85%. In conclusion TAP proves to be a valid and sensitive provocative test of ischemia when combined with myocardial scintigraphy and with Tc 99m-MIBI. © 1992, Sage Publications. All rights reserved.