Preconditioning effect during coronary angioplasty in patients with stable angina pectoris

Objective To determine whether collateral recruitment is involved in the preconditioning effect on the electrocardiogram, chest symptoms, and lactate metabolism during coronary angioplasty in patients with stable angina pectoris. Methods and Patients Sixteen patients with stable angina pectoris underwent three consecutive 2-min balloon inflations 5-min apart. The greatest ST elevation (DeltaSTmax), the sum of ST elevations in all leads (SigmaST), and QT dispersion (QTd) were measured at the end of each balloon inflation. Chest pain score was evaluated on a scale ranging from no pain (0) to the most severe pain (10). Lactate extraction ratio (LER) was determined by simultaneous blood sampling from the aorta and the coronary sinus. Collateral flow index (CFI) was derived from simultaneous measurements of mean aortic pressure and coronary wedge pressure obtained from a pressure guidewire during balloon inflation. Results Significant decreases were noted in DeltaSTmax (.3.3+/-2.1 vs. 3.0+/-1.9 vs. 2.6+/-1.8 mm, p<0.01), EST (9.7+/-7.2 vs. 8.5+/-6.1 vs. 6.9+/-5.3 mm, p<0.01), QTd (55.3+/-13.8 vs. 46.9+/-9.0 vs. 42.5+/-10.0 ms, p<0.01), and chest pain score (4.3+/-3.1 vs. 2.8+/-2.6 vs. 1.4+/-1.5, p<0.01) during the three sequential balloon inflations. LER significantly increased (-55.5+/-47.8 vs. -36.7+/-34.3 vs. -19.6+/-26.2%, p<0.01), indicating decreased lactate production. No significant difference was observed in CFI (0.16+/-0.10 vs. 0.15+/-0.10 vs. 0.15+/-0.10). Conclusion Repeated balloon inflations during coronary angioplasty elicited a preconditioning effect on ST-segment shift, QT dispersion, chest pain, and lactate production that does not involve collateral recruitment.