Is the rate of disappearance of echo contrast from the interventricular septum a measure of left anterior descending...

Area of Science:

• Cardiology
• Medical Imaging
• Diagnostic Techniques

Background:

• Myocardial contrast echocardiography (MCE) is a developing technique.
• Previous studies have not quantitatively correlated MCE findings with coronary artery stenosis severity.

Purpose of the Study:

• To investigate the quantitative relationship between myocardial echo contrast disappearance rate (T50) and the degree of coronary artery stenosis.
• To determine if T50 can serve as an index for regional myocardial perfusion.

Main Methods:

• Manual injection of sonicated iopamidol into the left main coronary artery.
• Cross-sectional echocardiography to capture myocardial echo-contrast images.
• Calculation of T50 from time-intensity curves and correlation with left descending coronary artery (LAD) stenosis percentage (%A) derived from arteriograms.

Main Results:

• A significant curvilinear relationship was observed between T50 and LAD %A (T50 = 3.0 x e0.01%A; r = 0.78; P < 0.05).
• Patients with asynergy exhibited significantly longer T50 values compared to those without.
• All patients with >75% LAD stenosis demonstrated prolonged T50.

Conclusions:

• Regional myocardial echo contrast washout (T50) is quantitatively related to the severity of coronary artery stenosis.
• T50 shows potential as a useful index for evaluating regional myocardial perfusion during cardiac catheterization.