Noninvasive identification of myocardium at risk in patients with acute myocardial infarction and nondiagnostic electrocardiograms with technetium-99m-Sestamibi.

Abstract

BACKGROUND:

Patients who have chest pain without electrocardiographic ST elevation are not candidates for thrombolytic therapy in most clinical trials. This study examined the value of technetium-99m-Sestamibi tomographic imaging to assess myocardial perfusion in patients during chest pain without ST elevation.

METHODS AND RESULTS:

Tc-99m-Sestamibi was injected in 14 patients who had chest pain without ST elevation, who subsequently developed enzymatic evidence of myocardial infarction within 24 hours. Tomographic imaging was performed 1-6 hours after injection. Thirteen of 14 patients showed significant perfusion defects indicative of acute myocardial infarction consistent with absent perfusion (20 +/- 15% of the left ventricle; range, 2-53%); one patient had normal images. Because of the absence of definitive electrocardiographic changes, only five patients received reperfusion therapy within 6 hours of the onset of chest pain. Regional wall motion abnormalities were present in nine of nine patients undergoing contrast ventriculography and correlated with the location of the Tc-99m-Sestamibi perfusion defect. At the time of subsequent coronary angiography, total arterial occlusion was present in 11 of the 14 patients. The infarct-related artery could be identified in 13 of the 14 patients. In six of these 13 patients, the left circumflex was the infarct-related artery.

CONCLUSIONS:

Patients who have chest pain without electrocardiographic ST elevation may have arterial occlusion and significant myocardium at risk. Tc-99m-Sestamibi imaging may be of benefit in identifying these patients early so that they can be considered for acute reperfusion therapy.

• Authors: T F Christian, I P Clements, R J Gibbons
• Journal: Circulation (Circulation) Vol. 83 Issue 5 Pg. 1615-20 (May 1991) ISSN: 0009-7322 [Print] United States
• PMID: 1827054 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Organotechnetium Compounds
• Technetium Tc 99m Sestamibi

Topics

• Aged
• Aged, 80 and over
• Angiography
• Coronary Angiography
• Electrocardiography
• Female
• Heart (physiopathology)
• Humans
• Male
• Middle Aged
• Myocardial Infarction (physiopathology)
• Organotechnetium Compounds
• Risk Factors
• Technetium Tc 99m Sestamibi
• Tomography