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Echocardiographic evaluation of left ventricular function during coronary artery angioplasty
Insights
Acute myocardial ischemia during coronary angioplasty significantly impairs left ventricular (LV) function, causing temporary dysfunction. Echocardiography and ECG changes confirm transient LV dysfunction during balloon occlusion.
Area of Science:
- Cardiology
- Cardiovascular Physiology
- Medical Imaging
Background:
- Percutaneous coronary angioplasty (PCA) with balloon occlusion offers a model to study acute myocardial ischemia.
- Left ventricular (LV) function is crucial in assessing cardiac health.
Purpose of the Study:
- To investigate the effects of acute myocardial ischemia on LV function during PCA.
- To correlate echocardiographic and electrocardiographic (ECG) findings during coronary occlusion.
Main Methods:
- Simultaneous M-mode and 2-D echocardiography and 6-lead ECG were recorded in 12 patients undergoing PCA.
- Coronary artery occlusion was induced using balloon angioplasty.
- LV function parameters and ECG changes were analyzed during occlusion and release.
Main Results:
- 90% of episodes showed significant decreases in LV systolic and diastolic function, wall thickness, and velocities during balloon occlusion.
- Echocardiography revealed hypokinesia, akinesia, or dyskinesia in 18 instances.
- LV dysfunction and ST-segment elevation on ECG occurred rapidly and resolved upon reperfusion.
Conclusions:
- Acute myocardial ischemia during PCA causes transient LV dysfunction.
- Echocardiography and ECG are sensitive tools for detecting and monitoring these functional changes.
- Collateral circulation may influence the severity of ischemic dysfunction.
Abstract:
Balloon occlusion of a stenotic coronary artery during percutaneous coronary artery angioplasty provides a unique opportunity to study the effect of acute myocardial ischemia on left ventricular (LV) function. Simultaneous M-mode and 2-dimensional (2-D) echocardiograms and a 6-lead electrocardiogram were recorded during 20 episodes of coronary artery occlusion and release in 12 patients. No patient had previous myocardial infarction and all had normal LV function by angiography. All patients had isolated single coronary artery disease, with left anterior descending stenosis in 8 and right coronary stenosis in 4. In 18 of 20 episodes (90%), M-mode echocardiography during balloon occlusion revealed a significant (p less than 0.001) decrease in LV systolic, diastolic and percent systolic wall thickness; systolic excursion; systolic and diastolic endocardial velocities; and fractional shortening. These changes were observed in the area of the ventricular septum in patients with left anterior descending occlusion and posteroinferior wall in those with right coronary artery occlusion. Two-dimensional echocardiography revealed varying degrees of hypokinesia, akinesia and dyskinesia during balloon occlusion in 18 instances. The echocardiographic changes were observed within 15 to 20 seconds of balloon occlusion and resolved 10 to 20 seconds after balloon deflation. All patients who had echocardiographic changes during balloon occlusion also had concomitant electrocardiographic (ECG) ST-segment elevation, whereas 2 patients with normal LV function had no ECG changes. Both of these patients had profuse collateral blood supply to the stenotic coronary artery. The echocardiographic and ECG abnormalities increased proportionately to the length of balloon occlusion. This study confirms previous animal and recent human studies of transient LV dysfunction during coronary occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)