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[Coronary angiography in patients with U wave inversion during coronary artery spasm]
1First Department of Internal Medicine, Faculty of Medicine, Mie University.
Insights
U wave inversion during ergonovine testing indicates coronary vasospasm. This finding suggests less severe myocardial ischemia compared to ST segment changes in vasospastic angina patients.
Area of Science:
- Cardiology
- Clinical Electrophysiology
- Interventional Cardiology
Background:
- Vasospastic angina (VSA) is a clinical syndrome characterized by reversible coronary artery spasm.
- Electrocardiographic (ECG) changes, such as ST-segment elevation or depression, are common during VSA episodes.
- The diagnostic utility of U wave inversion in VSA remains less understood.
Observation:
- Four patients undergoing ergonovine testing for suspected VSA presented with U wave inversion on precordial ECGs.
- No significant ST segment deviations were observed concurrently with U wave inversion.
- Coronary angiography revealed varying degrees of left anterior descending artery (LAD) spasm.
Findings:
- Ergonovine-induced U wave inversion correlated with coronary vasospasm.
- Angiographic findings in patients with U wave inversion indicated less severe myocardial ischemia than typically seen with ST deviations.
- One patient with total LAD occlusion showed collateral circulation, suggesting adaptation to chronic spasm.
Implications:
- U wave inversion during ergonovine testing can serve as a marker for coronary vasospasm.
- This ECG finding may represent a milder form of myocardial ischemia within the VSA spectrum.
- Further research is warranted to elucidate the prognostic significance of U wave inversion in vasospastic angina.
Abstract:
During ergonovine-induced vasospastic angina, U wave inversion without significant ST segment deviation on the precordial electrocardiograms was documented in four patients. Coronary angiography revealed incomplete spastic obstruction of the left anterior descending artery without delayed filling and runoff in three patients. In the remaining patient, the proximal left anterior descending artery was totally occluded and there were well-developed collaterals from the non-spastic artery. Thus, ergonovine-induced U wave inversion was related to the presence of coronary vasospasm, and angiography demonstrated less severe myocardial ischemia in such patients than in cases with ST segment elevation or depression, which is usually associated with subtotal or total obstruction of a major coronary artery without adequate collaterals. In their clinical courses, two patients had episodes of angina with ST segment elevations or depressions. It was suggested that vasospastic angina with U wave inversion alone is one aspect of a continuous spectrum of vasospastic myocardial ischemia.