title: Preventing phrenic nerve stimulation by a patch insulation in an intact swine heart model.
abstract: BACKGROUND
  Phrenic nerve stimulation (PNS) could be prevented by a silastic patch over the epicardial lead. We studied the effects in preventing PNS by placing a silastic patch directly over an epicardial lead or placing a graft around the phrenic nerve (PN).
  
  
  RESULTS
  Fourteen Lanyu swine were enrolled. A bipolar lead was placed epicardially on the left ventricle (LV) inferior to the PN. An implantable cardioverter-defibrillator (ICD) lead was placed into the right ventricle (RV). The maximal influential distance (MID) was measured under 3 pacing configurations to express the influential electrical field on the PN. The threshold of the LV and PN were evaluated epicardially. Then, PTFE patches of different sizes (10×10 mm, 20×20 mm and 30×30 mm) were placed between the LV lead and PN to study the rise in PN threshold in 7 swine. On the other hand, the PN were surrounded by a PTFE graft of different lengths (10 mm, 20 mm, and 30 mm) in the remaining 7 swine. LV-bipolar pacing showed the shortest MID when compared to the other 2 unipolar pacing configurations at pacing voltage of 10 V. The patch was most effective in preventing PNS during LV-bipolar pacing. PNS was prevented under all circumstances with a larger PTFE patch (30×30 mm) or long graft (30 mm).
  
  
  CONCLUSIONS
  PNS was avoided by placing a PTFE patch over the LV lead or a graft around the PN despite pacing configurations. Hence if PNS persisted during CRT implantation, a PTFE patch on the LV lead or a graft around the PN could be considered.
authors.affiliation: Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Institute, Department of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Department of Medicine, School of Medicine, Chung-Shan Medical University, Taichung, Taiwan.
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Huang
authors.affiliation: Institute of Clinical Medicine, and Cardiovascular Research Institute, Department of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan; Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Yenn-Jiang
authors.initials: YJ
authors.lastname: Lin
authors.affiliation: Department of Education and Research, Taichung Veterans General Hospital, Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Hung
authors.affiliation: Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan; Institute of Clinical Medicine, and Cardiovascular Research Institute, Department of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yu-Cheng
authors.initials: YC
authors.lastname: Hsieh
authors.affiliation: Division of Cardiology, Department of Medicine, Feng Yuan Hospital of the Ministry of Health and Welfare, Executive Yuan, Taichung City, Taiwan (R.O.C).
authors.forename: Chien-Ming
authors.initials: CM
authors.lastname: Cheng
authors.affiliation: Cardiovascular Center, Taichung Veterans General Hospital, Taichung, Taiwan; Department of Medicine, School of Medicine, Chung-Shan Medical University, Taichung, Taiwan.
authors.forename: Kuo-Yang
authors.initials: KY
authors.lastname: Wang
mesh_terms: D000818:Animals; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000379:methods; D058406:Cardiac Resynchronization Therapy; D006348:Cardiac Surgical Procedures; D017147:Defibrillators, Implantable / Q000009:adverse effects; D004567:Electrodes, Implanted / Q000009:adverse effects*; D006352:Heart Ventricles / Q000294:innervation* / Q000601:surgery; D010791:Phrenic Nerve / Q000502:physiology*; D011138:Polytetrafluoroethylene; D013552:Swine; D018487:Ventricular Dysfunction, Left / Q000628:therapy*
chemical_list: D011138:Polytetrafluoroethylene