Antiarrhythmic Effect of Bisoprolol, a Highly Selective .BETA.1-Blocker, in Patients With Paroxysmal Atrial Fibrillation

In the treatment of arrhythmia, β-blockers are mainly used to regulate the heart rate. However, β-blockers are also known as drugs with an antiarrhythmic effect due to the suppression of sympathetic activity. We evaluated the antiarrhythmic effects of a highly selective β1-blocker, bisoprolol, in patients with diurnal paroxysmal atrial fibrillation (P-AF). A total of 136 patients with symptomatic diurnal P-AF were enrolled. Patients were divided into a diurnal-specific P-AF group and a diurnal & nocturnal P-AF group, as well as into a bisoprolol single use group and a combined use group with an antiarrhythmic drug. The effects of bisoprolol were evaluated in 3 categories: subjective symptom improvement, quality of life (QOL) improvement, and elimination of P-AF episode in Holter electrocardiograms (ECGs). For patients with effective treatment, a long-term effect up to 24 months was evaluated. Five patients (3.7%) discontinued bisoprolol due to side effects. Following administration of bisoprolol, 109 patients (80%) experienced subjective symptom improvement, 103 patients (76%) experienced QOL improvement, and elimination of P-AF episodes in ECGs was observed in 84 patients (62%). The elimination rate of P-AF episodes in ECGs was higher in the diurnal P-AF group than in the diurnal & nocturnal P-AF group (P = 0.042). There was no significant difference between the bisoprolol single use group and the combined use group. A long-term suppressive effect by bisoprolol was observed in 70 of 83 patients (84%). The results demonstrate that bisoprolol has an antiarrhythmic effect against sympathetic diurnal P-AF, improving subjective symptoms and QOL and eliminating P-AF episodes in ECGs.