Termination of Atrial Fibrillation Using Pulsed Low-Energy Far-Field Stimulation

Article

关键词: CARDIAC TISSUE;    INTERNAL DEFIBRILLATION;    VIRTUAL ELECTRODES;    ELECTRICAL SHOCKS;    CARDIOVERSION;    EFFICACY;    MODEL;    TACHYARRHYTHMIAS;    ACTIVATION;    MECHANISMS;   

DOI  :  10.1161/CIRCULATIONAHA.108.825091

来源: SCIE

【 摘 要 】

Background-Electrically based therapies for terminating atrial fibrillation (AF) currently fall into 2 categories: antitachycardia pacing and cardioversion. Antitachycardia pacing uses low-intensity pacing stimuli delivered via a single electrode and is effective for terminating slower tachycardias but is less effective for treating AF. In contrast, cardioversion uses a single high-voltage shock to terminate AF reliably, but the voltages required produce undesirable side effects, including tissue damage and pain. We propose a new method to terminate AF called far-field antifibrillation pacing, which delivers a short train of low-intensity electric pulses at the frequency of antitachycardia pacing but from field electrodes. Prior theoretical work has suggested that this approach can create a large number of activation sites (virtual electrodes) that emit propagating waves within the tissue without implanting physical electrodes and thereby may be more effective than point-source stimulation. Methods and Results-Using optical mapping in isolated perfused canine atrial preparations, we show that a series of pulses at low field strength (0.9 to 1.4 V/cm) is sufficient to entrain and subsequently extinguish AF with a success rate of 93% (69 of 74 trials in 8 preparations). We further demonstrate that the mechanism behind far-field antifibrillation pacing success is the generation of wave emission sites within the tissue by the applied electric field, which entrains the tissue as the field is pulsed. Conclusions-AF in our model can be terminated by far-field antifibrillation pacing with only 13% of the energy required for cardioversion. Further studies are needed to determine whether this marked reduction in energy can increase the effectiveness and safety of terminating atrial tachyarrhythmias clinically. (Circulation. 2009;120:467-476.)

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