Evaluation of Post-Repolarization Refractoriness for Conduction Block in Cardiac Muscle

Monitoring the Progression of the Atrial Electrical Remodeling in Patients With Paroxysmal Atrial Fibrillation. Analysis of the f-f Interval During Ambulatory ECG Monitoring.

“…[20][21][22] The actual functional reentrant circuit is considered to have an excitable gap probably because of the influence of multiple anatomical obstacles (ie, vena cava, coronary sinus, pulmonary veins etc), in addition to the existence of post-repolarization refractoriness. [23][24][25] However, the local f-f interval during AF has been confirmed to have a good relationship with the local atrial refractoriness, although the AF reentrant circuit may involve an excitable gap to varying degrees. In our previous studies, we used the f-f interval in the surface ECG during PAF as an index of the complexity of the multiple AF reentrant circuits, 8 with the result that the f-f interval in the surface ECG showed a good direct relationship with the local f-f interval in the atrial electrogram.…”

Cardioprotective Effect of Mexiletine in Acute Myocardial Ischemia. Studies in the Rabbit Closed Chest Ischemia Model.

“…One reason for this finding is that mexiletine has been reported to suppress re-entrant arrhythmia regardless of the wavelength or the excitable gap of the re-entrant circuit by attenuation of the conduction block in a critical part of the re-entrant circuit. 35 Another reason is that the mechanism of the ventricular arrhythmia during the episode of acute ischemia may not be re-entry but triggered activity, which can be suppressed by shortening the action potential duration.…”

Effect of Procainamide on the Postrepolarization Refractoriness in Cardiac Muscle: Evaluation Using the Block Coupling Interval in the Artificial Isthmus Model in the Canine Right Atrium

“…1 In recent studies, PRR was calculated as the difference between the [effective refractory period and the duration of the monophasic action potential [ERP 2 MAP]. However, the authors previously demonstrated that the actual local coupling interval that caused the conduction block (i.e., the block coupling interval [BCI], [2][3][4][5] was significantly longer than the local ERP in the isthmus model in the canine heart. [2][3][4][5] Therefore, the PRR should be calculated using BCI instead of ERP when it is evaluated as the index for the conduction block.…”

“…However, the authors previously demonstrated that the actual local coupling interval that caused the conduction block (i.e., the block coupling interval [BCI], [2][3][4][5] was significantly longer than the local ERP in the isthmus model in the canine heart. [2][3][4][5] Therefore, the PRR should be calculated using BCI instead of ERP when it is evaluated as the index for the conduction block. [2][3][4][5] In the present study, the electrophysiological parameters (i.e., BCI, ERP, and MAP), that determine the conduction block were evaluated in an artificial isthmus model in the canine atrium, and the effect of procainamide on those parameters and PRR was evaluated.…”

“…[2][3][4][5] Therefore, the PRR should be calculated using BCI instead of ERP when it is evaluated as the index for the conduction block. [2][3][4][5] In the present study, the electrophysiological parameters (i.e., BCI, ERP, and MAP), that determine the conduction block were evaluated in an artificial isthmus model in the canine atrium, and the effect of procainamide on those parameters and PRR was evaluated.…”