Holter monitoring before, during and after percutaneous transluminal coronary angioplasty for evaluation of high-resolution trend recordings of leads CM5 and CC5 for ST-segment analysis.

Frequency-modulated Holter monitoring of leads CM5 and CC5 was performed before, during and after percutaneous transluminal coronary angioplasty (PTCA) in 16 patients with stenosis of the left anterior descending coronary artery, in 5 patients with stenosis of the left circumflex coronary artery, and in 5 patients with stenosis of the right coronary artery. All patients presented with 1-vessel coronary artery disease and stable or unstable angina pectoris. ST-segment analysis was based on high-resolution trend recordings. During balloon inflations all patients had significant (at least 0.1 mV) ST-segment changes in lead CM5. In lead CC5, associated ST-segment deviations were found in 22 of 26 patients. During 29.2 +/- 13.6 hours before PTCA, 90 spontaneous episodes with significant ST-segment deviations were detected in 10 patients. Of these episodes, 17% were characterized by ST-segment deviations in lead CC5 only, 57% by ST-segment deviations in lead CM5 only, and 27% by simultaneous ST-segment deviations in both leads. Asymptomatic episodes occurred twice as frequently as symptomatic episodes (66 vs 34%). Symptomatic episodes were more often characterized by ST-segment deviations of at least 0.15 mV (48 vs 9%, p less than 0.001) and by ST-segment deviations observed in both leads simultaneously (48 vs 15%, p less than 0.001). During 34.8 +/- 10.6 hours after successful PTCA, 5 spontaneous asymptomatic episodes with significant ST-segment deviations were detected in 2 patients.