Intracoronary electrocardiogram during coronary angioplasty.

This prospective study examines the data derived from the intracoronary electrocardiogram (ECG) (derived from the coronary guide wire) compared with that from four standard surface leads (I, II, III, and V2) in documenting myocardial ischemia during coronary angioplasty. Intracoronary and surface ECGs were simultaneously recorded in 300 consecutive patients (mean age 59 +/- 10; range 33 to 80 years; 246 males [82%] during coronary angioplasty in 368 lesions (167 left anterior descending [46%], 85 left circumflex [23%], 107 right coronary arteries [29%], and nine bypass grafts [2%]), before balloon inflation, at 1 minute of inflation, and at the end of the procedure. ST segment changes (greater than 0.1 mV) were observed in the intracoronary ECG in 306 lesions (83%) (151 left anterior descending [88%], 75 left circumflex [89%], and 80 right coronary arteries [73%]) versus in 245 lesions (67%) in the surface ECG (126 left anterior descending [73%], 43 left circumflex [47%], and 76 right coronary arteries [70%]; [p less than 0.0001]). The mean ST segment shift was 0.5 +/- 0.4 mV in intracoronary and 0.1 +/- 0.2 mV in standard leads (p less than 0.0001). ST elevation was seen in 97% of cases with intracoronary ECG changes versus in 83% with surface ECG changes. The remainder had ST depression. A total of 48 lesions (13%) did not produce ECG changes and 62 (16%) had silent ischemia. In 75 lesions (21%), ECG changes were seen only in the intracoronary ECG, compared with 14 lesions (4%) with changes only in the surface ECG (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)