Proarrhythmic and Torsadogenic Effects of Potassium Channel Blockers in Patients

Publication date: Available online 22 March 2016 Source:Cardiac Electrophysiology Clinics Author(s): Mark McCauley, Sharath Vallabhajosyula, Dawood DarbarTeaser The most common arrhythmia requiring drug treatment is atrial fibrillation (AF), which affects 2 to 5 million Americans and continues to be a major cause of morbidity and increased mortality. Despite recent advances in catheter-based and surgical therapies, antiarrhythmic drugs continue to be the mainstay of therapy for most patients with symptomatic AF. However, many antiarrhythmics block the rapid component of the cardiac delayed rectifier potassium current (IKr) as a major mechanism of action, and marked QT prolongation and pause-dependent polymorphic ventricular tachycardia (torsades de pointes) are major class toxicities.
Source: Cardiac Electrophysiology Clinics - Category: Cardiology Source Type: research