Action Potential Triangulation Explains Acute Proarrhythmic Effect of Aliskiren in a Whole-Heart Model of Atrial Fibrillation.

Action Potential Triangulation Explains Acute Proarrhythmic Effect of Aliskiren in a Whole-Heart Model of Atrial Fibrillation. Cardiovasc Toxicol. 2019 Jun 07;: Authors: Ellermann C, Mittelstedt A, Wolfes J, Willy K, Leitz P, Reinke F, Eckardt L, Frommeyer G Abstract Recent experimental studies showed a protective effect of the renin inhibitor aliskiren regarding atrial structural remodeling. Purpose of this study was to assess acute electrophysiologic effects of aliskiren in a whole-heart model of atrial fibrillation (AF) and to investigate its impact on the ventricle. Twelve rabbit hearts were excised, retrogradely perfused, and paced at different cycle lengths. To enhance atrial vulnerability, a combination of acetylcholine (ACh) and isoproterenol (Iso) was infused and significantly reduced atrial action potential duration (aAPD90) and atrial effective refractory period (aERP). Additional infusion of aliskiren prolonged aAPD90 but did not alter aERP. A triangulation of action potential with ACh/Iso and a further triangulation after treatment with aliskiren were noted. Vulnerability to AF was tested by employing trains of burst pacing. Administration of ACh/Iso provoked more episodes of AF (baseline: 26 episodes, Iso/Ach: 48 episodes). Additional treatment with aliskiren induced AF significantly more often (108 episodes). Another nine hearts were perfused with aliskiren to examine its ventricular effects. Infusion with aliskiren ab...
Source: Cardiovascular Toxicology - Category: Cardiology Authors: Tags: Cardiovasc Toxicol Source Type: research