Study population
This was a single-center, nonrandomized, observational study. Consecutive patients with paroxysmal AF who underwent CA between August 2015 and August 2019 at our institution were retrospectively evaluated. We excluded patients who 1) did not undergo P-SAECG, 2) were receiving a class I, III, or IV antiarrhythmic drug at the time of P-SAECG, or 3) were lost to follow-up (Figure 1). This study was approved by the Ethics Committee of Kitasato University Hospital (No. B18-197).