Evaluation of body surface potential mapping changes after successful percutaneous transluminal coronary angioplasty.

OBJECTIVE

To assess the progress of chronic myocardial ischemia after successful percutaneous transluminal coronary angioplasty (PTCA) using body surface potential mapping (BSPM).

DESIGN

For BSPM analysis the following kinds of maps were used: isopotential repolarization maps corresponding to 70% of ST-T interval's duration and isointegral maps corresponding to 0% to 20% of ST-T duration. BSPM measurements were taken before the PTCA and usually one to six days after this intervention. In 17 patients BSPM was carried out within two days after PTCA. Eleven to 14 BSPM examinations were usually carried out during six months of follow-up. Control coronary angiography was performed after six months in all but three patients.

RESULTS

Substantial focal decrease of positive potential in repolarization caused by myocardial ischemia recovered gradually after successful PTCA. This appeared to be caused by the regression of "hibernating myocardium'. An increase of positive potential was statistically significant (P < 0.01) after the fifth week of PTCA intervention. There was a positive correlation between BSPM findings and chest discomfort of patients after PTCA. Chronic myocardial ischemia could be observed on isopotential and/or isointegral maps examined before the PTCA in 21 of 25 cases (sensitivity 84%).