Abstract
BackgroundUpregulation of the two-pore-domain potassium channel TASK-1 (hK2P3.1) was recently described in patients suffering from atrial fibrillation (AF) and resulted in shortening of the atrial action potential. In the human heart, TASK-1 channels facilitate repolarization and are specifically expressed in the atria. In the present study, we tested the antiarrhythmic effects of the experimental ion channel inhibitor A293 that is highly affine for TASK-1 in a porcine large animal model of persistent AF.MethodsPersistent AF was induced in German landrace pigs by right atrial burst stimulation via implanted pacemakers using a biofeedback algorithm over 14 days. Electrophysiological and echocardiographic investigations were performed before and after the pharmacological treatment period. A293 was intravenously administered once per day. After a treatment period of 14 days, atrial cardiomyocytes were isolated for patch clamp measurements of currents and atrial action potentials. Hemodynamic consequences of TASK-1 inhibition were measured upon acute A293 treatment.ResultsIn animals with persistent AF, the A293 treatment significantly reduced the AF burden (6.5% vs. 95%; P < 0.001). Intracardiac electrophysiological investigations showed that the atrial effective refractory period was prolonged in A293 treated study animals, whereas, the QRS width, QT interval, and ventricular effective refractory periods remained unchanged. A293 treatment reduced the upregulation of the TASK-1 current as well as the shortening of the action potential duration caused by AF. No central nervous side effects were observed. A mild but significant increase in pulmonary artery pressure was observed upon acute TASK-1 inhibition.ConclusionPharmacological inhibition of atrial TASK-1 currents exerts in vivo antiarrhythmic effects that can be employed for rhythm control in a porcine model of persistent AF. Care has to be taken as TASK-1 inhibition may increase pulmonary artery pressure levels.
Highlights
Atrial fibrillation (AF) represents a major clinical and socioeconomic burden (Hindricks et al, 2020)
A293 Protects From AF-Induced Atrial Effective Refractory Period (AERP) Shortening
To investigate whether A293 can be used for rhythm control in a porcine model of persistent AF, we performed EP investigations and implanted pacemaker devices in 15 pigs
Summary
Atrial fibrillation (AF) represents a major clinical and socioeconomic burden (Hindricks et al, 2020). Novel mechanism-based therapeutic approaches might improve the effectiveness and safety of pharmacologic AF treatment (Peyronnet and Ravens, 2019). In this context, it will be important to find an atrial-selective therapeutic target for AF therapy. Upregulation of the two-pore-domain potassium channel TASK-1 (hK2P3.1) was recently described in patients suffering from atrial fibrillation (AF) and resulted in shortening of the atrial action potential. We tested the antiarrhythmic effects of the experimental ion channel inhibitor A293 that is highly affine for TASK-1 in a porcine large animal model of persistent AF
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