Effect of Chronic Amiodarone Therapy on Excitable Gap During Typical Human Atrial Flutter

Abstract

EG in patients under chronic amiodarone therapy is significantly larger than in controls, mainly because of a longer fully EG. This observation may be explained by opposite effects on conduction velocity and refractoriness.

Synergistic Electrophysiologic and Antiarrhythmic Effects of the Combination of Ranolazine and Chronic Amiodarone in Canine Atria

“…Chronic amiodarone is the most effective pharmacological agent available for the maintenance of sinus rhythm following termination of AF 8. The anti-arrhythmic efficacy of chronic amiodarone has been attributed to the multiplicity of effects on ion channel activity (Class I, II, III and IV actions), reduction of transmural dispersion of repolarization, induction of post-repolarization refractoriness, prolongation of excitable gap, suppression of triggered activity, and inhibition of atrial remodeling 8,17,19,36,38,39…”

Potent Antiarrhythmic Effects of Chronic Amiodarone in Canine Pulmonary Vein Sleeve Preparations

“…Chronic amiodarone is still considered the most effective pharmacological agent currently available for the maintenance of sinus rhythm following termination of AF 2. The antiarrhythmic efficacy of chronic amiodarone has been related to the multiplicity of effects on ion channel activity (Class I, II, III and IV actions), resulting in the reduction of dispersion of repolarization, induction of postrepolarization refractoriness, prolongation of the excitable gap, suppression of triggered activity and attenuation of atrial remodeling 2,25,27,39,41,42…”

Electrophysiologic Mechanism of Typical Atrial Flutter Termination by Nifekalant: Effect of a Pure IKr‐Selective Blocking Agent

“…Amiodarone, which is the major class III antiarrhythmic drug, has complex pharmacological effects associated with multiple ion channel blocking effects. Previous reports showed its low efficacy for the termination of AFL, because of the slowing of conduction velocity through its sodium channel blocking effect, which results in the increase in the excitable gap and thus stabilizes AFL. Therefore, a pure I Kr blocking agent was suggested to be more effective for AFL termination because it prolongs AERP without causing a decrease in conduction velocity.…”