COMPARISON OF STANDARD AND DERIVED 12-LEAD ELECTROCARDIOGRAMS FOR DIAGNOSIS OF CORONARY ANGIOPLASTY-INDUCED MYOCARDIAL-ISCHEMIA

To determine whether a derived 12-lead electrocardiogram (EGG) would d emonstrate typical ST-segment changes of ischemia during percutaneous transluminal coronary angioplasty (PTCA), 207 patients were monitored with continuous 12-lead ST-segment monitoring during angioplasty. Addi tionally, to compare the derived and standard ECGs during known period s of ischemia with PTCA balloon inflation, 151 patients were recorded with both electrocardiographic methods during the procedure. Of the 20 7 patients recorded with the derived EGG, 171 (83%) had typical ischem ic ST-segment changes during PTCA balloon inflation. The amplitudes of these ST deviations were similar to those observed during transient m yocardial ischemia observed in clinical settings (median peak ST devia tion, 225 mu V). There was agreement regarding presence or absence of ischemia in 150 of the 151 patients recorded with both derived and sta ndard electrocardiographic methods (> 99% agreement). With use of the standard ECG as the ''gold standard'' for ischemia diagnosis, there we re no false-positive results and only 1 false-negative result with the derived EGG. Furthermore, there was nearly perfect agreement between the two 12-lead methods in terms of anterior versus inferior wall patt erns of ischemia. Future studies are required to determine whether con tinuous monitoring with a derived ECG would improve diagnosis and lead to better patient outcomes. (C) 1997 by Excerpta Medica, Inc.