ST‐segment computerized monitoring before and after angioplasty: Clinical correlation with recurrent angina during the short‐term follow‐up

The purpose of this study was to determine whether computerized ST‐segment monitoring previous to percutaneous transluminal coronary angioplasty (PTCA) and after performance of this procedure may be useful to discern a pattern of recurrent angina. For this purpose, we analyzed 57 patients (11 women and 46 men, mean age 60 years) before and after treatment with balloon procedure. These patients were followed up during the next 3 months. A computerized electrocardiographic (ECG) device was used which was capable of recording simultaneously all 12 leads at rest. It was programmed to store a complete ECG every 5 min and was capable of detecting any abnormal ST alteration > than 0.5 mV at 80 ms after J junction, including R‐wave amplitude. Measurements were started before (mean time 7.26 h) and after (mean time 7.96 h) the procedure. The value for ST amplitude at the J junction was used as the 0 point; then the most negative depression or the most positive elevation value was considered as the most abnormal ST alteration during monitoring. The patients were followed up for 3 months for the purpose of recognizing recurrent angina or establishing the occurrence of death. Twelve patients (30%) had recurrent angina. Discriminant function analysis revealed that ST monitoring in these patients showed significant difference after PTCA in comparison with controls, both in the frontal plane [ST depression 170 ± 52 mV vs. 231 ± 23 (p = 0.02)J and in precordial leads [176 ± 16 vs. 80 ± 6.19 mV (p = 0.0001)]. Among patients who had no recurrent angina there were significant changes in the horizontal plane [171 ± 18.3 mV vs. 156 ± 14.7 mV (p = 0.007)] but not in the frontal plane [213 ± 17.67 mV vs. 195 ± 75.2 mV (p = NS)]. There were no significant changes when the ST slope was evaluated as elevated among patients with or without recurrent angina. In this pilot study, the computer method using continuous recording data to determine whether significant differences existed among groups showed that ST‐segment depression in the frontal leads before PTCA could contribute to identifying a group of patients at risk of developing recurrent angina soon after PTCA.