IMPACT OF TRANSIENT MYOCARDIAL-ISCHEMIA O N LATE POTENTIALS IN TRANSLUMINAL CORONARY ANGIOPLASTY IN PATIENTS WITH CORONARY HEART-DISEASE

The frequency of recording late potentials and their dynamics were stu died in 25 patients with coronary heart disease before, during, and af ter transluminal angioplasty (TAP). Baseline late potentials were obse rved in 6 (20.7 %) cases. During TAP, late potentials were recorded si gnificantly more frequently (48.3 %) than the baseline ones (p<0.03), in 6 (20.7 %) patients, late potentials appeared only in arterial dila tation and disappeared after TAP. There was a profound decrease in roo t-mean-square amplitude of late 40 msec in the QRS complex and an incr ease in the duration of low-amplitude (less than 40 muV) signals at th e end of the QRS complex as compared to the baseline values. In ST-seg ment elevation, the parameters of the ECG signal-average become deteri orated to a greater degree than those in ST-segment depression.