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Influence of coronary collaterals on left ventricular function in patients undergoing coronary angioplasty
F Khaja1, H G Sabbah, J F Brymer
1Henry Ford Heart and Vascular Institute, Detroit, MI 48202.
Insights
Coronary collaterals preserve left ventricular function during temporary coronary artery blockage. This study shows that patients with collaterals maintained normal heart function, unlike those without.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Coronary artery disease can lead to transient myocardial ischemia.
- The role of coronary collaterals in maintaining cardiac function during ischemia is not fully understood.
Purpose of the Study:
- To investigate the impact of coronary collaterals on global left ventricular function during temporary coronary artery occlusion.
- To assess the protective effect of collaterals in patients undergoing percutaneous transluminal coronary angioplasty (PTCA).
Main Methods:
- Noninvasive evaluation of left ventricular systolic function using peak aortic blood acceleration via continuous-wave Doppler.
- Measurements taken before, during, and after balloon inflation in 37 patients undergoing PTCA.
- Patients categorized based on the presence or absence of angiographic evidence of collaterals.
Main Results:
- Patients without collaterals showed a significant decrease in peak acceleration during occlusion (16.0 to 11.8 m/sec/sec, p < 0.001).
- Peak acceleration returned to baseline levels after reperfusion in patients without collaterals.
- Patients with collaterals maintained stable peak acceleration throughout occlusion and reperfusion, indicating preserved left ventricular function.
Conclusions:
- Coronary collaterals play a crucial role in preserving left ventricular systolic function during transient coronary occlusion in humans.
- The presence of collaterals prevents the decline in cardiac function observed during acute ischemia.
- These findings highlight the importance of collateral circulation in mitigating ischemic damage.
Abstract:
The purpose of this study was to determine the role of coronary collaterals on global left ventricular function during transient coronary occlusion. Left ventricular systolic function was evaluated noninvasively in 37 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) by means of peak aortic blood acceleration measured with a continuous-wave Doppler velocity meter placed suprasternally. Doppler measurements were made before, during, and immediately after balloon inflation. Nineteen patients underwent PTCA of the left anterior descending coronary artery, 15 of the right coronary artery, and three of the circumflex coronary artery. All patients had a subtotal coronary occlusion. Among the 37 patients 23 had no angiographic evidence of collaterals supplying the vessel undergoing PTCA and 14 had collaterals. In patients without collaterals peak acceleration was 16.0 +/- 3.0 m/sec/sec before balloon occlusion and decreased to 11.8 /+- 3.6 m/sec/sec within 30 to 40 seconds of coronary occlusion (p less than 0.001). After 30 to 40 seconds of reperfusion (balloon deflated), peak acceleration returned to near- preocclusion levels (17.3 +/- 7.5 m/sec/sec). Among patients with collaterals peak acceleration remained unchanged during balloon occlusion and reperfusion relative to preocclusion levels (NS). These data indicate that collaterals can preserve left ventricular function during transient coronary occlusion in humans.