Precardial ST segment depression in patients with acute inferior myocardial infarction is highly correlated with dipyridamole induced left ventricular dyssynergy outside the infarct zone

ABSTRACT

The purpose of this study was to determine the correlations between precordial ST segment depression appearing during acute inferior myocardial infarction, and Dipyridamole induced left ventricular wall motion abnormalities detected by two dimensional echocardiography. Thirty patients with acute inferior myocardial infarction were allocated into two groups [15 patients each] based on the presence [group A] or absence [group B] of precordial ST segment depression. Group A patients had higher serum creatin kinase activity than group B [1340 +/- 235 vs 825 +/- 114 IU/L mean +/- SD respectively P<0.001]. Left ventricular dyssynergy, defined as akinesia or dyskinesia, occured within the infarct zone [inferior segments] more frequently in group A than group B[15/15 vs 10/15 respectively P<0.001]. Dipyridamole infusion induced left ventricular dyssynergy within regions outside the infarct zone in 12/15 patients of group A [4inferoseptal,4anteroseptal,4anterior]. Dipyridamole did not induce any regional dyssynergy outside the infarct zone in any patient of group B [P< 0.001]. Precordial ST segment depression in patients with acute inferior myocardial infarction reflected, in this study, Dipyridamole induced left ventricular dyssynergy outside the infarct zone with 100% sensitivity and 83% specificity. Our data are in favour of the theory that precordial ST segment depression in acute inferior myocardial infarction indicates myocardial ischemia and not due to reciprocal electrophysiologic changes