Pharmacological prevention and termination of focal atrial fibrillation

Circadian (diurnal/nocturnal) pattern of cardiac arrhythmias

Circadian rhythms follow 24-hour biological cycle patterns controlled by internal biological or circadian clocks that optimize organismal homeostasis according to predictable environmental changes. These clocks are found in virtually all cells in the body, including cardiomyocytes. Triggers for and/or the occurrence of sudden cardiac death (SCD) and cardiac arrhythmias seem to follow such daily patterns. This review highlights data from studies exploring the role of day/night rhythms in the timing of arrhythmic events, studies describing the environmental, behavioral, and circadian mechanisms regulating cardiac electrophysiology focusing on the circadian pattern of arrhythmias and SCD. Mechanisms involved relate to circadian control of electrophysiological properties, vagal tone, and sleep disorders, as well as the potential interaction and synergism among these factors. By studying the diurnal variations of arrhythmias, therapy can be improved by optimally timing it to their circadian pattern and a person's internal body clock time. Potential treatment targets for arrhythmias with nocturnal onset may include upstream therapy for underlying comorbidities, type and timing of drug intake, pulmonary vein isolation, ablation of the ganglionated plexus, and autonomic nervous system control. Thus, specific history-taking, screening, and diagnostic workup are recommended to identify and characterize comorbidities and potential contributors to nocturnal arrhythmias, such as obesity, advanced age, diabetes, hypertension, and heart failure. In this direction, symptoms of sleep apnea may comprise snoring and excessive daytime sleepiness. Risk factors include obesity, decreased upper airway dimensions, and heart failure. Thus, one should have a low threshold for sleep testing to assess for sleep apnea. Sleep apnea treatment decreases ventricular arrhythmias and ameliorates some severe bradycardic episodes, often obviating the need for pacemaker implantation. Importantly, comorbidity treatment and lifestyle optimization remain crucial.

Impact of bisoprolol transdermal patch on early recurrence during the blanking period after atrial fibrillation ablation

BACKGROUND

Early recurrences of atrial arrhythmias (ERAAs) after ablation may require therapeutic intervention. The optimal medical therapy that prevents ERAAs requires clarification. This study aimed to compare the incidence of ERAAs between patients who received or did not receive bisoprolol transdermal patches (BTPs) at 3 months postablation.

METHODS

This single-center retrospective study enrolled 203 consecutive patients with paroxysmal atrial fibrillation (AF) who had undergone their first ablation, comprising 59 in the BTP group and 144 in the non-BTP group. Follow-up assessments were conducted monthly for 3 months. We evaluated the incidence of ERAAs.

RESULTS

During the initial 1-week observational period, the rate of ERAAs was lower in the BTP group (5.0%) than that in the non-BTP group (18.8%) (P = .013). At 3 months postablation, the rate of ERAAs was lower in the BTP group (6.8%) than that in the non-BTP group (25.7%) (P = .002). The cumulative freedom from ERAAs was significantly lower in the BTP group than in the non-BTP group (log-rank: P = .003). Administering BTPs was an independent factor that protected against ERAAs (odds ratio 0.181, [95% confidence interval 0.059-0.559], P = .003).

CONCLUSION

BTPs may prevent ERAAs after ablation.