A 54-year-old man with paroxysmal atrial fibrillation underwent pulmonary vein (PV) isolation using a 28 mm second-generation cryoballoon catheter. Unexpected electrical superior vena cava (SVC) isolation during cryoballoon application to the right superior PV was observed in the first procedure. Thirteen-months after cryoballoon-based PV isolation, sustained SVC fibrillation was confirmed irrespective of sinus rhythm. Voltage mapping visualized a low voltage area around the SVC was consistent with that around the right superior PV. SVC isolation was obtained by cryoballoon application to the right superior PV and persisted for over a year.

Introduction: To know whether cardiac pacemaker implantations improve the functional capacity (FC) and affect the prognosis. Methods and Results: We prospectively enrolled 621 de-novo pacemaker recipients (age 76±9 years, 50.7% male) between April 2015 and September 2016. The FC was assessed by the metabolic equivalents (METs) during the implantation and periodically thereafter. The patients were a priori classified into a poor FC (<2 METs, n=40 [6.4%]), moderate FC (24 METs, n=342 [55.1%]). Three months after the pacemaker implantation, poor FC or moderate FC patients improved to a good FC by 43%. The distribution of the three FCs remained at those levels by the end of the follow-up (p=0.18). During a median follow-up of 2.4 years, 71 patients (11%) had cardiovascular hospitalizations and 35 (5.6%) all-cause death. A multivariate Cox analysis revealed that a poor FC at baseline was an independent predictor of both a cardiovascular hospitalization (hazard ratio [HR] 2.494, 95% confidence interval [CI] 1.227-5.070, p=0.012) and all-cause death (HR 3.338, 95% CI 1.254-8.886, p=0.016). One year after the pacemaker implantation, the 19 patients whose poor FC improved to a good FC did not die, however, the 8 who remained with a poor FC had a high mortality rate of 37.5% (p<0.01). Conclusion: Approximately half of the poor or moderate FC patients improved to a good FC 3 months after the pacemaker implantation. The baseline FC predicted the prognosis, and patients with an improved FC after the pacemaker implantation had a better prognosis.