TY - JOUR

T1 - Inhibition of the acetylcholine-regulated potassium current prevents transient apnea-related atrial arrhythmogenic changes in a porcine model

AU - Norup Hertel, Julie

AU - Linz, Benedikt

AU - Isaksen, Jonas

AU - Jerltorp, Kezia

AU - Leonhardt, Caroline

AU - Gottlieb, Lisa

AU - Saljic, Arnela

AU - Jespersen, Thomas

AU - Linz, Dominik

N1 - Publisher Copyright: © 2024 Heart Rhythm Society

PY - 2024

Y1 - 2024

N2 - Background: More than 50% of patients with atrial fibrillation (AF) suffer from sleep disordered breathing (SDB). Obstructive respiratory events contribute to a transient, vagally mediated atrial arrhythmogenic substrate, which is resistant to most available antiarrhythmic drugs. Objective: The purpose of this study was to investigate the effect of pharmacologic inhibition of the G-protein–gated acetylcholine-regulated potassium current (IK,ACh) with and without acute autonomic nervous system activation by nicotine in a pig model for obstructive respiratory events. Methods: In 21 pigs, SDB was simulated by applying an intermittent negative upper airway pressure (INAP). AF inducibility and atrial effective refractory periods (aERPs) were determined before and during INAP by an S1S2 atrial pacing-protocol. Pigs were randomized into 3 groups—group 1: vehicle (n = 4); group 2: XAF-1407 (IK,ACh inhibitor) (n = 7); and group 3: nicotine followed by XAF-1407 (n = 10). Results: In group 1, INAP shortened aERP (ΔaERP –42.6 ms; P = .004) and transiently increased AF inducibility from 0% to 31%. In group 2, XAF-1407 prolonged aERP by 25.2 ms (P = .005) during normal breathing and prevented INAP-induced aERP shortening (ΔaERP –3.6 ms; P = .3) and AF inducibility. In group 3, INAP transiently shortened aERP during nicotine perfusion (ΔaERP –33.6 ms; P = .004) and increased AF inducibility up to 61%, which both were prevented by XAF-1407. Conclusion: Simulated obstructive respiratory events transiently shorten aERP and increase AF inducibility, which can be prevented by the IK,ACh-inhibitor XAF-1407. XAF-1407 also prevents these arrhythmogenic changes induced by obstructive respiratory events during nicotine perfusion. Whether IK,ACh channels represent a target for SDB-related AF in humans warrants further study.

AB - Background: More than 50% of patients with atrial fibrillation (AF) suffer from sleep disordered breathing (SDB). Obstructive respiratory events contribute to a transient, vagally mediated atrial arrhythmogenic substrate, which is resistant to most available antiarrhythmic drugs. Objective: The purpose of this study was to investigate the effect of pharmacologic inhibition of the G-protein–gated acetylcholine-regulated potassium current (IK,ACh) with and without acute autonomic nervous system activation by nicotine in a pig model for obstructive respiratory events. Methods: In 21 pigs, SDB was simulated by applying an intermittent negative upper airway pressure (INAP). AF inducibility and atrial effective refractory periods (aERPs) were determined before and during INAP by an S1S2 atrial pacing-protocol. Pigs were randomized into 3 groups—group 1: vehicle (n = 4); group 2: XAF-1407 (IK,ACh inhibitor) (n = 7); and group 3: nicotine followed by XAF-1407 (n = 10). Results: In group 1, INAP shortened aERP (ΔaERP –42.6 ms; P = .004) and transiently increased AF inducibility from 0% to 31%. In group 2, XAF-1407 prolonged aERP by 25.2 ms (P = .005) during normal breathing and prevented INAP-induced aERP shortening (ΔaERP –3.6 ms; P = .3) and AF inducibility. In group 3, INAP transiently shortened aERP during nicotine perfusion (ΔaERP –33.6 ms; P = .004) and increased AF inducibility up to 61%, which both were prevented by XAF-1407. Conclusion: Simulated obstructive respiratory events transiently shorten aERP and increase AF inducibility, which can be prevented by the IK,ACh-inhibitor XAF-1407. XAF-1407 also prevents these arrhythmogenic changes induced by obstructive respiratory events during nicotine perfusion. Whether IK,ACh channels represent a target for SDB-related AF in humans warrants further study.

KW - Acetylcholine-regulated potassium current

KW - Atrial fibrillation

KW - Autonomic nervous system

KW - I

KW - Nicotine

KW - Obstructive sleep apnea

U2 - 10.1016/j.hrthm.2024.01.033

DO - 10.1016/j.hrthm.2024.01.033

M3 - Journal article

C2 - 38280622

AN - SCOPUS:85186633115

JO - Heart Rhythm

JF - Heart Rhythm

SN - 1547-5271

ER -