Homogenization of Atrial Electrical Activities: Conceptual Restoration of Regional Electrophysiological Parameters to Deter Ischemia-Dependent Conflictogenic Atrial Fibrillation.

Abstract

Atrial fibrillation (AF) as a severe arrhythmia is now spreading worldwide at overwhelmingly high rates, particularly in elderly patients. Despite new insights, the mechanisms underlying AF are not conclusively determined yet. Taking into account the ischemic origin of arrhythmia induction (according to the so-called conflictogenic atrial fibrillation, declared recently) restoration of regional electrophysiological parameters is essential in tackling AF. We hypothesized that some atrial electrophysiological parameters, preferably the effective refractory period, might need to be controlled to prevent AF. All the remaining parameters - conduction velocity, conduction time, recovery time, vulnerability, excitability, repolarization etc. being as if secondary and less important could be ignored. Homogenization of the milieu producing AF might be implemented, at least theoretically, through restoration of blood supply in ischemic areas and/or via attenuation of electrophysiological differences between conflicting regions by delivery of atrial sub-threshold non-captured pulse-trains. Adjunctive therapy by drugs containing vasodilatory features and affecting the effective refractory period appears to be fundamental. Thus, stabilization of disorganized atrial cellular activities likely may lead to the recovery of atrial excitable characteristics. Despite the lack of compelling evidence, the application of the concept may be helpful in order to search for more precise and more effective methods to favorably change the refractory period. Further studies are necessary to determine whether restoration or improvement of blood circulation of atrial wall is feasible. Based on such considerations a novel preventive AF strategies are to be designed.