CORONARY VASOREACTIVITY TO ERGONOVINE AFTER ANGIOPLASTY - DIFFERENCE BETWEEN THE INFARCT-RELATED CORONARY-ARTERY AND THE NONINFARCT-RELATEDCORONARY-ARTERY

Background: The vasoreactivity after direct percutaneous transluminal coronary angioplasty (PTCA) in patients with previous myocardial infar ction remains unknown. We examined the constrictor response to ergonov ine of the infarct-related coronary artery in comparison with that of noninfarct-related coronary artery after angioplasty. Methods: Ergonov ine was administered intravenously to 17 patients with previous myocar dial infarction (group I) and to 21 patients with stable angina (group II) 1 year after PTCA. The effects of ergonovine on lumen diameter we re analysed quantitatively at the PTCA segment, nonPTCA segment (proxi mal to the PTCA segment), and nonPTCA artery. Results: The ergonovine- induced decrease in minimal lumen diameter at the PTCA segment was sig nificant in group I (decrease from 2.12 +/- 0.56 to 1.39 +/- 0.74 mm, P < 0.01), but not in group II (decrease from 1.60 +/- 0.35 to 1.43 +/ - 0.33 mm, NS). Patients in group I showed a constrictor response at t he nonPTCA artery (decrease in diameter from 2.54 +/- 0.90 to 1.94 +/- 0.77 mm, P < 0.01), and a tendency to constrict at the nonPTCA segmen t (2.56 +/- 0.67 to 2.11 +/- 0.66 mm, P = 0.06), whereas those in grou p II showed no significant constrictor response to ergonovine at any o f the three segments examined. The changes in diameter at the three se gments in patients in group I were significantly greater than those in group II tall P < 0.01). Subtotal coronary spasm at the PTCA segment was provoked only in three patients in group I (18%). Conclusions: The constrictor response to ergonovine of the infarct-related coronary ar tery was enhanced compared with that of the noninfarct-related coronar y artery. This difference in coronary vasoreactivity at the angioplast y segment may be due to previous hypersensitivity of the smooth muscle . Coronary Artery Dis 9:105-111 1998 Lippincott-Raven Publishers.