RESUMO
BACKGROUND: Cryoballoon pulmonary vein isolation (PVI) is a common therapy for atrial fibrillation (AF). While moderately increased sinus rhythm heart rate (HR) after PVI has been observed, inappropriate sinus tachycardia (IST) is a rare phenomenon. We aimed to investigate the prevalence and natural history of an abnormal sinus HR response after cryoballoon PVI. METHODS: We included 169/646 (26.2%) patients with AF undergoing PVI with available Holter recordings before and 3, 6 and 12 months after the procedure. Patients with AF on Holter monitoring were excluded. Mean HR increase ≥â¯20â¯bpm or an IST-like pattern (mean HR >â¯90â¯bpm or >â¯80â¯bpm when beta-blocking agents were used) following PVI was categorised as abnormal sinus HR response. RESULTS: Following PVI, mean HR⯱ standard deviation increased in the entire group from 63.5⯱ 8.4 to 69.1⯱ 9.9â¯bpm at 3 months (pâ¯< 0.001), and to 71.9⯱ 9.4â¯bpm at 6 months (pâ¯< 0.001). At 12 months, mean HR was 71.2⯱ 10.1â¯bpm (pâ¯< 0.001). Only 7/169 patients (4.1%) met criteria for abnormal sinus HR response: mean HR was 61.9⯱ 10.6â¯bpm (pre-ablation), 84.6⯱ 9.8â¯bpm (3 months), 80.1⯱ 6.5â¯bpm (6 months) and 76.3⯱ 10.1â¯bpm (12 months). Even at 12 months, mean HR was significantly different from that pre-ablation in this group (pâ¯= 0.033). However, in patients meeting IST-like pattern criteria, mean HR at 12 months was no longer significantly different from that pre-ablation. CONCLUSION: Few patients had an abnormal sinus HR response after PVI. Peak HR was observed 3 months after PVI, but HR was still significantly increased 12 months post-ablation compared with pre-ablation. An IST-like pattern was rarely observed. In these patients, HR decreased to pre-ablation values within a year.