Conscious sedation during cryoballoon ablation of atrial fibrillation: a feasibility and safety study

BACKGROUND: Cryoballoon ablation for atrial fibrillation (cryoAF) is relatively simple, cost-effective and easy procedure. However, general anesthesia during this procedure may have negative impact on patients' mortality and morbidity, as well as procedure costs. We sought to assess the feasibility and safety of conscious sedation during cryoAF. METHODS: Patients with paroxysmal or persistent, drug-refractory AF who underwent a first procedure of cryoAF were included in our single-center, retrospective study. The loading dose of midazolam was 2 mg and loading fentanyl dose was 25 µg intravenously. Additional doses of midazolam and fentanyl were administered, if necessary. Midazolam and fentanyl were administered to maintain amnesia and analgesia, and patients' responsiveness in Ramsay Sedation Score was assessed every 10 minutes with sedation kept at the Ramsey Sedation Scale not exceeding Ramsey 3 Grade. RESULTS: A total of 71 patients with mean age 59.5±11.1 years were enrolled (48 males, 68%). The TEE and the TEE-guided transseptal puncture was feasible in all patients. The mean duration of cryoAF procedure was 136.3±36.0 minutes. The overall mean midazolam and fentanyl used doses were: 5.1±3.1 mg (55.7±35.1 µg/kg) and 98.9±51.1 µg (1.13±0.60 µg/kg). In 3 patients (4.2%), vascular complications occurred (femoral vein bleeding with hematoma formation without communication with femoral artery). In 1 case (1.4%) transient right phrenic palsy was observed; symptoms disappeared completely within 12 hours after procedure. The overall acute procedural success rate of cryoAF (defined as electrical isolation of all pulmonary veins) was 68/71 (95.8%). CONCLUSIONS: Conscious sedation is a safe, efficacious and feasible during cryoablation of pulmonary veins for AF.