Assessment of Left Ventricular Function in Acute Myocardial Infarction: The Relationship between Global Ejection Fraction and Regional Wall Motion

The relationship between regional and global left ventricular (LV) function in acute myocardial infarction (MI) was determined from the contrast ventriculograms of 84 patients. Motion was measured at 100 chords perpendicular to a centerline drawn midway between the end-systolic and end-diastolic endocardial contours and expressed in units of standard deviations from normal. Hypokinesis was computed as the mean motion of chords in the part of the infarct artery territory with most depressed function. Function in the noninfarct region was computed as the mean motion of chords in the most contractile part. Hypokinesis correlated poorly (r = 0·47) with the ejection fraction (EF) due to the effect of hyperkinesis or hypokinesis in the noninfarct region. Net abnormality, the algebraic sum of motion abnormalities in the infarct and noninfarct regions, correlated much better with the EF(r = 0·85). The extent to which regional myocardial performance is depressed at the site of acute MI cannot be assessed from the EF due to the influence of function in the noninfarct region. The method presented allows quantitative assessment of regional wall motion in both regions in a manner that allows calculation of their net contributions to global LV function. Assessment of LV dysfunction in acute infarction, or of change in function following infarction, should be performed by measuring regional wall motion.