Abstract：Objective To compare the effectiveness and safety of secondgeneration cryoballoon ablation and conventional drug therapy separately as the initial treatment for patients with paroxysmal atrial fibrillation (AF). Methods We selected 44 patients with paroxysmal AF who had been initially treated by secondgeneration cryoballoon ablation as the ablation group. The operation time, ablation time, X-ray fluoroscopy time, pulmonary vein isolation rate, and surgical complications were observed. We selected another 44 inpatients with paroxysmal AF who had been initially treated by drug therapy during the same period as the medication group. The two groups were followed up separately one month, and 3, 6 and 12 months after discharge to observe the recurrence rate and complications of AF. The efficacy and safety of treatment were further compared between the two groups. Results The operation time, ablation time and X-ray fluoroscopy time of the ablation group were (108.0±39.0) minutes, (35.0±11.7) minutes and (10.0±6.9) minutes, respectively; the immediate isolation rate of pulmonary vein was 100%; there were 3 cases (6.8%) of operationrelated complications, including one case of vagus reflex and 2 cases of transient phrenic nerve injury. In the medication group, drug-induced sinus bradycardia occurred in 2 cases, QTc was prolonged in one case, and thyroid function was decreased in one case. After a mean follow-up of (12.0±5.) months, the recurrence rate of AF was 11.4% in the ablation group while the rate was 20.5% in the medication group. The recurrence rate in the ablation group was significantly lower than that in the medication group (P=0.033). The incidence of complications or adverse reactions did not vary significantly from the ablation group to the medication group (6.8% vs 9.1%, P=0.108). Conclusion Compared with drug therapy, the secondgeneration cryoballoon ablation has a higher success rate for paroxysmal AF without increased risk of complications. The secondgeneration cryoballoon ablation can be considered as one of the initial treatment strategies for paroxysmal AF.
