AIM  To evaluate the effect of sotalol hydrochloride on atrial vulnerable period in patients with paroxysmal atrial fibrillation.

  METHOD  50 patients with paroxysmal atrial fibrillation were selected as PAF group and 50 patients without atrial fibrillation as non-PAF group. Atrial vulnerable period was measured through esophagus atrial pacing in both groups. Regression analysis was performed between atrial vulnerable period and the frequency of episodes in one year. After recovering sinus rhythm, 50 patients with atrial fibrillation were randomly divided into intervention group and placebo group. They were treated with sotalol hydrochloride (40 mg, twice a day) and placebo respectively. The clinical observation lasted for six months. If atrial fibrillation recurred, the observation was terminated. Survival analysis was performed after the end of the observation, and the atrial vulnerable period was measured again, and the paired test was performed after the intervention.

  RESULTS  39 cases were induced by atrial fibrillation in PAF group, while only 7 cases in non-PAF group were induced. The atrial vulnerable period of PAF group was significantly longer than that of non-PAF group (t = 4.541, P<0.01). The atrial vulnerable period in 50 cases of atrial fibrillation was positively correlated with the frequency of episodes in the previous year (P<0.01). The recurrence rate of atrial fibrillation was 28% in the sotalol hydrochloride intervention group and 64% in the placebo group. The recurrence rate of the intervention group was significantly lower than that of the placebo group (P<0.05), and the atrial vulnerable period of the intervention group was significantly shortened (P<0.05), and was also significantly shorter than before intervention (P<0.01).

  CONCLUSION  The atrial vulnerable period of patients with paroxysmal atrial fibrillation is significantly prolonged and positively correlated with the frequency of episodes. Sotalol hydrochloride can significantly shorten the atrial vulnerable period and reduce the recurrence rate, thus improving the quality of life, reducing the number of visits and hospitalizations.