Melatonin prevents reperfusion arrhythmias by receptor-dependent and independent electrophysiological effects

BERNIKOVA OG; VAYKSHNORAYTE MA; AZAROV JE; DIEZ ER; SEDOVA KA; KHARIN SN

Munich

Congreso; ESC Congress 2018; 2018

European Society of Cardiology

Introduction: Ventricular arrhythmias are complications during reperfusion ofacute coronary syndromes. Melatonin reduces the incidence and duration of ventricular arrhythmias, but its protective mechanism remains elusive. This study aimed to investigate whether melatonin receptors contribute to an activation or/and repolarization as the antiarrhythmic action during reperfusion.Methods: Open-chest anesthetized female rats underwent regional ischemia for eight minutes to induce reperfusion arrhythmias. Before reperfusion, four groups of animals intravenously received: melatonin (4 mg/kg), a melatonin receptorblocker (luzindole 0.4 mg/kg), melatonin + luzindole, or placebo. Unipolar Electrograms were recorded from ischemic and nonischemic areas using an array of 64-electrodes to obtain the activation time, repolarization time and dispersion of repolarization.Results: Melatonin reduced reperfusion arrhythmias (1 of 9 vs. controls 11 of 16, P=0.0112). Luzindole made the protection disappear (luzindole 4 of 6, luzindole + melatonin 6 of 8; both n.s.). Luzindole increased activation time in the reperfused area (luzindole 14.6 ms, melatonin + luzindole 15.1 vs. control 11.7 ms and melatonin 11.0 ms, P