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[Stress myocardial scintigraphy in coronary artery disease: its clinical significance]
1First Department of Internal Medicine, Nippon Medical School, Tokyo.
Insights
Asymptomatic ST depression in coronary artery disease patients differs in clinical significance. Myocardial perfusion defects are more common in patients with prior myocardial infarction (MI) than those with angina alone.
Area of Science:
- Cardiology
- Diagnostic Imaging
Background:
- Asymptomatic ischemic heart disease requires evaluation for clinical significance.
- Exercise electrocardiography and stress myocardial scintigraphy are key diagnostic tools.
Purpose of the Study:
- To assess the clinical significance of asymptomatic ST depression in patients with coronary artery disease.
- To differentiate the implications of asymptomatic ST depression in patients with and without prior myocardial infarction (MI).
Main Methods:
- 70 patients with coronary artery disease underwent exercise electrocardiography and thallium myocardial scintigraphy.
- Tests were correlated with exercise symptoms and history of MI.
- Transient myocardial ischemia was identified by perfusion defects on imaging immediately post-exercise.
Main Results:
- Asymptomatic ST depression occurred in 53% of MI patients and 58% of angina patients.
- Transient myocardial perfusion defects were significantly higher in MI patients (61%) compared to angina patients (33%) (p < 0.05).
Conclusions:
- Asymptomatic ST depression may have different clinical significance in patients with versus without a history of MI.
- Stress myocardial scintigraphy is crucial for identifying significant ischemia in these patient groups.
Abstract:
To evaluate the clinical significance of asymptomatic ischemic heart disease, exercise electrocardiography and stress myocardial scintigraphy were performed. These were correlated with symptoms during exercise tests and histories of myocardial infarction (MI). The study subjects consisted of 70 patients with coronary artery disease, including 34 with MI, and 36 without MI but with angina pectoris. Stress tests were performed using bicycle ergometer under electrocardiographic monitoring throughout the test. Transient myocardial ischemia was confirmed by perfusion defects on thallium myocardial imaging demonstrated immediately after exercise, but not 3 hours after the stress test. Asymptomatic ST depression was observed in 18 of 34 patients with MI (53%) and in 21 of the 36 patients with angina (58%); however, transient myocardial perfusion defects were confirmed in 61% of the patients with MI (11 of 18 patients), but in only 33% of those with angina (7 of 21 patients). The difference was statistically significant (p less than 0.05). It was suggested that there are some differences in the clinical significance of asymptomatic ST depression between the patients with MI and those without MI but with angina pectoris.