Correlative study of regional left ventricular histology and contractile function

In 110 patients with documented coronary artery disease, transmural biopsy of the anteroapical region of the left ventricle was performed during aortocoronary bypass grafting. Biopsy specimens were semiquantitatively graded microscopically for myocardial fibrosis as an indicator of chronic ischemic damage. Preoperatively, systolic wall motion of the region from which the biopsy specimen was taken was semiquantitatively graded as showing normal motion, hypokinesia, akinesia or dyskinesia on ventriculography. Wall motion-histologic correlations, taking into account both electrocardiographic evidence of anterior infarction and ST-T abnormalities, were then established. Overall, there was fair agreement (72 percent) between functional and histologic assessment of the left ventricular region evaluated, both qualitatively (normal versus abnormal, 72 percent agreement) and quantitatively (degree of abnormality, correlation coefficient 0.66, P = 0.005). The 22 patients with electrocardiographic evidence of anterior infarction had various degrees of abnormal regional motion and myocardial fibrosis. Discordance between wall motion and histologic findings was most common (50 percent of instances) in the 34 patients with anterior ST-T changes without infarction and generally was manifest as abnormal motion with normal histologic features. By contrast, normal motion and abnormal histologic features represented the most common type of discordance (22 percent of instances) in the 54 patients without either anterior infarction or ST-T deviation. These data provide a basis for inference of myocardial morphologic features (fibrosis) from assessment of ventriculographic wall motion and the electrocardiogram. They may thus be useful in predicting the potential functional benefits of bypass grafting of coronary arteries supplying abnormally contractile segments of the left ventricle.