The authors studied the involvement of IKr @entity972 current in @entity2224 during perfusion. Electrophysiologic parameters were measured before and after @entity2781 administration (2.5, 7.5, and 12.5 x 10-7 M, n = 8) in isolated perfused feline hearts. During pacing, these parameters included epicardial conduction time, refractoriness, and the fastest rate for 1:1 pacing/response capture. During 8 minutes of electrically induced @entity591 , they included heart rate and normalized entropy reflecting the degree of organization. In all groups, @entity943 rate was slower in the right ventricle than in the left ventricle. @entity2781 decreased the @entity943 rate more than it increased organization, reduced its maintenance, or increased difficulty in initiation. Refractoriness was prolonged in a reverse use-dependent way which was less than 1:1 pacing/response capture. Unexpectedly, a moderate prolongation of conduction time was observed. Inverse correlation was found between the @entity943 rate and changes in refractoriness and conduction time and between the degree of organization and refractoriness (both ventricles) and conduction time (right ventricle). @entity2781 , which intensively blocks IKr current and unexpectedly suppressed conduction, has different quantitative effects on fibrillation features. These changes in fibrillation suggest that these effects are mainly associated with refractoriness prolongation and do not seem to be attenuated by conduction suppression.

Modulation of XXXX in isolated perfused heart by @entity2781 .

@entity2781 :: ('MESH:C063533', 'Chemical') :: ['dofetilide', 'Dofetilide'] @entity591 :: ('MESH:D013610', 'Disease') :: ['tachyarrhythmias'] @entity2224 :: ('MESH:D014693', 'Disease') :: ['ventricular fibrillation'] @entity972 :: ('MESH:D011188', 'Chemical') :: ['potassium'] @entity943 :: ('MESH:D001145', 'Disease') :: ['arrhythmia']
@entity2224 :: (MESH:D014693,Disease) :: ['ventricular fibrillation']
