Quantitative regional wall motion analysis with early contrast ventriculography for the assessment of myocardium at risk in acute myocardial infarction

Background

Several techniques have been used to quantify the myocardium at risk, including measurement of regional ventricular function with contrast ventriculography and measurement of perfusion defect size with tomographic technetium-99m-sestamibi imaging. This study evaluates the correlation between these 2 techniques.

Methods

Twenty-three patients with angiographically documented coronary occlusion and acute myocardial infarctions (10 anterior, 13 inferior) were studied. All patients had contrast left ventriculography at the time of their acute angiogram before any revascularization therapy. Regional wall motion parameters measured with the centerline method were the severity, circumferential extent, and global circumferential extent of hypokinesis and the mean standardized motion in predefined areas. Technetium-99m-sestamibi was injected before reperfusion therapy with measurement of the myocardium at risk using single photon emission computed tomography imaging.

Results

The tomographic sestamibi-measured myocardium at risk was significantly greater for anterior infarctions compared with inferior infarctions (40% ± 18% vs 14.0 ± 8.5%, P = .0001). The only parameter of regional wall motion to show a significant difference by infarct location was global circumferential extent of hypokinesis (43% ± 25% vs 22% ± 15%, P = .02). The other parameters were not significantly different between anterior and inferior myocardial infarctions. For anterior infarctions, these parameters of regional wall motion correlated with myocardium at risk assessed with sestamibi: global circumferential extent of hypokinesis (r = .88, P < .01), circumferential extent of hypokinesis (r = .78, P < .01), mean standardized motion in predefined areas (r = -.74, P < .05), and severity of hypokinesis (r = -.70, P < .05). For inferior infarctions, there was no significant correlation between any of these parameters of regional wall motion and myocardium at risk assessed with sestamibi imaging.

Conclusion

The assessment of regional ventricular function with contrast ventriculography correlates with the area of myocardium at risk measured with tomographic technetium-99m-sestamibi for anterior, but not for inferior, myocardial infarctions. Therefore, these parameters of regional wall motion are a poor measure of the efficacy of reperfusion therapies.