Heart Rhythm:耳屏经皮电刺激有望成为房颤无创治疗

We studied the effects of transcutaneous electrical stimulation at the tragus, the anterior protuberance of the outer ear, for inhibiting atrial fibrillation (AF).

In 16 pentobarbital anesthetized dogs, multi-electrode catheters were attached to pulmonary veins and atria. Three tungsten-coated microelectrodes were inserted into the anterior right ganglionated plexi to record neural activity. Tragus stimulation (20 Hz) in the right ear was accomplished by attaching two alligator clips onto the tragus. The voltage slowing the sinus rate or AV conduction was used as the threshold for setting the low-level tragus stimulation (LL-TS) at 80% below threshold. At baseline, programmed stimulation determined the effective refractory period (ERP) and the window of vulnerability (WOV), a measure of AF inducibility. For hours 1-3, rapid atrial pacing (RAP) was applied alone, followed by concomitant RAP+LL-TS for hours 4-6 (N=6). The same parameters were measured during sinus rhythm, when RAP stopped after each hour. In 4 other animals, bi-vagal transection was performed before LL-TS.

During hours 1-3 of RAP, there was a progressive and significant decrease in ERP, increase in WOV and increase in neural activity vs. baseline (all p<0.05). With RAP+LL-TS during hours 4-6, there was a linear return of ERP, WOV and neural activity towards baseline levels (all p<0.05; compared to the 3rd hour values). In 4 dogs, bi-vagal transection prevented the reversal of ERP and WOV despite 3 hours of RAP+LL-TS.