BACKGROUND: @entity24724 (D) is developed to maintain sinus rhythm in @entity1 suffering from @entity955 . The aim of the present study was to investigate, whether @entity24724 also has an antiarrhythmic potential in the ventricle and to elucidate the mechanisms for its low proarrhythmic potential in an experimental whole heart model. METHODS AND RESULTS: Thirty-five @entity95 underwent chronic treatment with D (n = 15; 50 mg    kg(-1)    d(-1)) and @entity2643 (A; n = 20; 50 mg    kg(-1)    d(-1)). Hearts were perfused on a Langendorff apparatus. Results were compared with hearts acutely treated with @entity2778 (S; 50-100  M; n = 14). A 12-lead electrocardiogram and up to 8 ventricular epi- and endocardial monophasic action potentials showed a significant prolongation of QT interval (D: +24 milliseconds, A: +28 milliseconds, S: +35 milliseconds (50  M), +56 milliseconds (100  M); P < 0.02) compared with baseline. In contrast to D and A, S led to a significant increase in dispersion of repolarization and exhibited reverse use dependence. D, A, and S increased refractory period, resulting in a significant increase in postrepolarization refractoriness (effective refractory period minus action potential duration; D = +12 milliseconds; A = +14 milliseconds; S = +25 milliseconds; P < 0.05). S led to a triangular action potential configuration, whereas D and A caused a fast phase 3 prolongation. After lowering of @entity972 concentration, 50% of S-treated hearts showed @entity1166 , in contrast to an absence of @entity1166 in D and A. CONCLUSIONS: Prolongation of myocardial repolarization and postrepolarization refractoriness by D may act antiarrhythmic. A fast phase 3 repolarization in the absence of both increased dispersion of repolarization and reverse use dependence prevents proarrhythmia.

Electrophysiologic profile of XXXX on the ventricular level: beneficial effect on postrepolarization refractoriness in the presence of rapid phase 3 repolarization.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity2643 :: ('MESH:D000638', 'Chemical') :: ['amiodarone'] @entity1166 :: ('MESH:D016171', 'Disease') :: ['torsade de pointes'] @entity95 :: ('9986', 'Species') :: ['rabbits'] @entity2778 :: ('MESH:D013015', 'Chemical') :: ['sotalol'] @entity24724 :: ('MESH:C118667', 'Chemical') :: ['Dronedarone', 'dronedarone'] @entity955 :: ('MESH:D001281', 'Disease') :: ['atrial fibrillation'] @entity972 :: ('MESH:D011188', 'Chemical') :: ['potassium']
@entity24724 :: (MESH:C118667,Chemical) :: ['dronedarone']
