Abstract
Background and Aim : There has been little information available on the significance of the changes in the STa level in the unipolar electrogram during pulmonary vein isolation (PVI). We examined whether the elevation of the STa in PVI is an indicator of atrial injury. Methods : The study was performed in the 11 cases of atrial fibrillation (AF) undergoing PVI. The unipolar electrogram from the ablation (ABL) catheter tip was recorded during PVI, and the variation in the STa during and after the radiofrequency application was analyzed and compared with the variation in the amplitude of bipolar electrogram. An 8mm tip catheter was used, and the RF power and the tip temperature were set at 30-35 watts and 50 degrees for 30-45 seconds, respectively. Results : The 68 applications were analyzed. The STa elevation occurred just after the ABL, reached the peak at 10-20 seconds after ABL, and improved thereafter, and the STa level at 1 minute after termination of ABL was 88.7%of the level at the peak. The bipolar electrogram amplitude after ABL was 57.8% of the control level, and a morphology change. Conclusion : The STa elevation during PVI was thought to be an indicator of efficient ABL.
