vernakalant and Ventricular-Fibrillation

Ranolazine has been reported to have an antiarrhythmic potential. The aim of this study was to assess the electrophysiologic effects of ranolazine and to compare its effects to vernakalant in an experimental whole-heart model of short-QT syndrome.. Rabbit hearts were isolated and Langendorff-perfused. After obtaining baseline data, pinacidil, an IK. Endo- and epicardial monophasic action potentials and a 12-lead ECG showed a significant abbreviation of QT interval (- 34 milliseconds, P < 0.05) and action potential duration (APD. In the present pharmacologic model of short QT syndrome treatment with pinacidil led to an increased inducibility of VF in association with a reduction in ERP. Additional treatment with ranolazine or vernakalant reversed this effect and demonstrated potent antiarrhythmic properties based on an increase of ERP.

Topics: Action Potentials; Animals; Anisoles; Anti-Arrhythmia Agents; Arrhythmias, Cardiac; Cardiac Pacing, Artificial; Disease Models, Animal; Electrocardiography; Heart Rate; Isolated Heart Preparation; Pinacidil; Pyrrolidines; Rabbits; Ranolazine; Sodium Channel Blockers; Time Factors; Ventricular Fibrillation