Prospective analysis of electrocardiographic variables as markers for extent and location of acute wall motion abnormalities observed during coronary angioplasty in human subjects.

To assess the usefulness of different electrocardiographic variables as markers for the presence, extent and location of new wall motion abnormalities seen after sudden controlled coronary occlusion, 23 patients with isolated left anterior descending (n = 12), or right (n = 11) coronary artery disease and a normal baseline left ventriculogram were prospectively studied during transluminal coronary angioplasty. A simultaneous 12 lead electrocardiogram was recorded before passing the balloon catheter and again at 30 seconds into the fourth inflation cycle. Using a second arterial catheter, a left ventriculogram was obtained at 40 seconds into the fourth inflation cycle. The extent of wall motion abnormalities was described as the percent of left ventricular perimeter showing hypocontractility. During balloon inflation, 19 of the 23 patients developed new hypocontractility ranging from 3 to 40%. ST segment elevation in lead V2 was the most sensitive marker for anterior wall hypocontractility and ST segment elevation in lead III was the most sensitive marker for inferior wall hypocontractility. Highly significant correlations were observed between the extent of the hypocontractile perimeter and 1) the sum of ST segment elevation in all 12 leads; 2) the magnitude of ST segment elevation in either lead V2 or lead III; and 3) the total number of leads with ST elevation greater than or equal to 0.5 mV. No significant changes were seen in the sum of R wave amplitudes, but a significant prolongation of the QT interval was seen during ischemia. In conclusion, acute ST segment elevation parallels the development of new asynergy during transluminal coronary angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)