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Stenosis severity and the occurrence of ventricular ectopic activity during acute coronary occlusion during balloon
K E Airaksinen1, M J Ikäheimo, H V Huikuri
1Department of Medicine, University of Oulu, Finland.
Insights
Early ventricular arrhythmias (VA) during acute coronary occlusion are linked to less severe stenosis and anterior coronary artery occlusion. These findings highlight electrical instability risks even with non-obstructive plaques.
Area of Science:
- Cardiology
- Electrophysiology
- Vascular Biology
Background:
- Acute coronary occlusion can precipitate cardiac electrical instability.
- Understanding the determinants of early ventricular arrhythmias (VA) is crucial for risk stratification.
Purpose of the Study:
- To determine the incidence and predictors of early VA during acute coronary artery occlusion.
- To investigate the relationship between stenosis severity, collateral circulation, and VA occurrence.
Main Methods:
- Continuous electrocardiographic, heart rate, and blood pressure monitoring in 152 patients undergoing coronary artery balloon occlusion.
- Comparison with a control group (13 patients) with chronic total coronary occlusion.
- Stepwise logistic regression analysis to identify significant predictors of VA.
Main Results:
- Ventricular arrhythmias occurred in 12% of patients during acute coronary occlusion.
- Milder stenosis severity (72% vs. 81%) and anterior coronary artery occlusion were associated with higher VA incidence.
- ST-segment deviations were more frequent in patients who developed VA.
Conclusions:
- Stenosis severity and the site of coronary occlusion are key predictors of early VA.
- Less advanced coronary lesions may lead to electrical instability more readily than advanced ones.
- Collateral circulation status did not significantly influence VA occurrence in this study.
Abstract:
To elucidate the incidence and determinants of early ventricular arrhythmias (VA) during acute coronary occlusion, continuous electrocardiographic, heart rate, and blood pressure recordings were performed in 152 patients during standardized balloon occlusions of significant (50% to 95%) coronary artery stenoses. A control group of 13 patients with chronic total occlusion of a coronary artery was also studied. None of them developed VA during balloon inflation in the preexisting total occlusion of the artery. Balloon occlusion of a coronary artery was associated with occurrence of ventricular ectopy in 18 patients (VA group, 12%). The VA group had milder stenosis severity (72% vs 81%, p < 0.001) than the rest of the patients, and none of them had visible collaterals to the occluded vessel. The VA group also had ST-segment deviations more often (p < 0.05) during occlusion than patients with no VA. Occlusion of the left anterior descending artery caused VA more often (p < 0.05) than occlusion of the left circumflex or right coronary artery. No clinical or hemodynamic variable or medication was associated with the occurrence of VA. In stepwise logistic regression analysis, the only significant predictors of ventricular ectopic activity were the stenosis severity and the anterior site of coronary occlusion. Even a nonstenotic plaque can be so fragile that it is prone to rupture. The present findings suggest that such an occlusion may result in electrical instability more easily than occlusion of a more advanced coronary lesion.