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ST segment alternans during coronary angioplasty.
M Sochanski1, T Feldman, K G Chua
1University of Chicago Hospitals, Department of Medicine, Hans Hecht Hemodynamics Laboratory, Illinois 60637.
Catheterization and Cardiovascular Diagnosis
|September 1, 1992
Summary
ST alternans, a sign of cardiac electrical instability, was observed in four patients during percutaneous coronary intervention (PCI). This phenomenon during PCI may be influenced by medications like calcium channel blockers.
Area of Science:
- Cardiology
- Electrophysiology
- Interventional Cardiology
Background:
- ST alternans, characterized by beat-to-beat variation in ST-segment morphology, can indicate myocardial ischemia or electrical instability.
- Previous studies in animals and patients with variant angina described ST alternans, often linked to premature ventricular contractions.
Observation:
- Four patients undergoing balloon angioplasty for severe proximal or mid-left anterior descending (LAD) artery stenosis exhibited ST alternans.
- Neither mechanical alternans nor increased ventricular ectopy were observed concurrently.
- ST alternans did not follow premature ventricular contractions, differing from prior reports.
Findings:
- The occurrence of ST alternans during percutaneous transluminal coronary angioplasty (PTCA) is infrequent.
- The mechanism of ST alternans during PTCA may differ from that observed in variant angina or animal models.
- Frequent use of calcium channel blockers during PTCA might interfere with the development of electrical alternans.
Implications:
- Understanding the specific triggers and mechanisms of ST alternans during PTCA is crucial for accurate interpretation.
- The influence of pharmacologic agents, such as calcium channel blockers, on electrical alternans during interventional procedures warrants further investigation.
- These findings highlight potential differences in the pathophysiology of ST alternans in the context of acute procedural ischemia versus other conditions.