title: The use of low-level electromagnetic fields to suppress atrial fibrillation.
abstract: BACKGROUND
  Extremely low-level electromagnetic fields have been proposed to cause significant changes in neural networks.
  
  
  OBJECTIVE
  We sought to investigate whether low-level electromagnetic fields can suppress atrial fibrillation (AF).
  
  
  METHODS
  In 17 pentobarbital anesthetized dogs, bilateral thoracotomies allowed the placement of multielectrode catheters in both atria and at all pulmonary veins. AF was induced by rapid atrial pacing (RAP) or programmed atrial extrastimulation. At baseline and end of each hour of RAP, during sinus rhythm, atrial programmed stimulation gave both the effective refractory period (ERP) and the width of the window of vulnerability. The latter was a measure of AF inducibility. Microelectrodes inserted into the anterior right ganglionated plexi recorded neural firing. Helmholtz coils were powered by a function generator inducing an electromagnetic field (EMF; 0.034 μG, 0.952 Hz). The study sample was divided into 2 groups: group 1 (n = 7)-application of EMF to both cervical vagal trunks; group 2 (n = 10)-application of EMF across the chest so that the heart was located in the center of the coil.
  
  
  RESULTS
  In group 1, EMF induced a progressive increase in AF threshold at all pulmonary vein and atrial sites (all P < .05). In group 2, the atrial ERP progressively shortened and ERP dispersion and window of vulnerability progressively increased (P < .05 compared to baseline values) during 3 hours of RAP and then returned to baseline values during 3 hours of combined application of RAP and EMF (P < .05 compared to the end of the third hour of RAP). The frequency and amplitude of the neural activity recorded from the anterior right ganglionated plexi were markedly suppressed by EMF in both groups.
  
  
  CONCLUSIONS
  Pulsed EMF applied to the vagal trunks or noninvasively across the chest can significantly reverse AF inducibility.
authors.affiliation: Department of Cardiology, Renmin Hospital, Wuhan University, Wuhan, China.
authors.forename: Lilei
authors.initials: L
authors.lastname: Yu
authors.affiliation: Heart Rhythm Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: John W
authors.initials: JW
authors.lastname: Dyer
authors.affiliation: Heart Rhythm Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Scherlag
authors.affiliation: Heart Rhythm Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Stavros
authors.initials: S
authors.lastname: Stavrakis
authors.affiliation: Heart Rhythm Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Yong
authors.initials: Y
authors.lastname: Sha
authors.affiliation: Heart Rhythm Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Xia
authors.initials: X
authors.lastname: Sheng
authors.affiliation: Heart Rhythm Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
authors.forename: Paul
authors.initials: P
authors.lastname: Garabelli
authors.affiliation: Pico-Tesla Magnetic Therapies LLC, Littleton, Colorado.
authors.forename: Jerry
authors.initials: J
authors.lastname: Jacobson
authors.affiliation: Heart Rhythm Institute and Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma. Electronic address: sunny-po@ouhsc.edu.
authors.forename: Sunny S
authors.initials: SS
authors.lastname: Po
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000628:therapy; D004285:Dogs; D004574:Electromagnetic Fields; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D006325:Heart Atria / Q000601:surgery; D006329:Heart Conduction System / Q000503:physiopathology; D023421:Models, Animal; D011667:Pulmonary Veins / Q000601:surgery; D055536:Vagus Nerve Stimulation / Q000379:methods*
keywords: Atrial fibrillation; Autonomic nervous system; Electromagnetic field