Role of beta-adrenergic modulation of action potential duration in arrhythmogenesis in Long QT Syndrome Type 1 & 2

INTRODUCTION: Congenital Long QT Syndromes type 1 and 2 (LQT1 and LQT2) are life-threatening conditions that arise from functional impairment of delayed rectifier potassium channels and predispose individuals to ventricular arrhythmias (VAs) such as polymorphic ventricular tachycardia and ventricular fibrillation (VF). Sympathetic surges have been associated with VA onset in LQTS, but mechanisms of initiation are not fully understood. It is therefore necessary to investigate the effects of β-adrenergic receptor (β-AR) stimulation on ventricular electrophysiology in LQT1 and LQT2. METHODS: ) and VF threshold (VFT). RESULTS: was steeper. CONCLUSION: suggest that each LQT subtype may have different arrhythmogenic mechanisms.