Improved Outcomes of Cardiopulmonary Resuscitation in Rats Treated With Vagus Nerve Stimulation and Its Potential Mechanism

Shock. 2018 Jun;49(6):698-703. doi: 10.1097/SHK.0000000000000962.

Abstract

Studies have demonstrated that vagus nerve stimulation (VNS) reduces ischemia/reperfusion injury. In this study, we investigated the protective effects of VNS in a rat model of cardiopulmonary resuscitation (CPR). We further investigated whether the beneficial effects of VNS were dependent on the alpha 7 nicotinic acetylcholine receptor (α7nAChR). Forty animals were randomized into four groups and all underwent CPR (n = 10 each): CPR alone (control); VNS during CPR; α7nAChR antagonist methyllycaconitine citrate (MLA) with VNS; α7nAChR agonist 3-(2, 4-dimethoxybenzylidene) anabaseine (GTS-21 dihydrochloride) without VNS. The right vagus nerve was exteriorized in all animals. Ventricular fibrillation was induced and untreated for 8 min. Defibrillation was attempted after 8 min of CPR. VNS was initiated at the beginning of precordial chest compressions and continued for 4 h after return of spontaneous circulation (ROSC) in both the VNS and MLA groups. Hemodynamic measurements and myocardial function, including ejection fraction and myocardial performance index, were assessed at baseline, 1 and 4 h after ROSC. The neurological deficit score was measured at 24-h intervals for a total of 72 h. The heart rate was reduced in the VNS and MLA groups, while no difference was found in mean arterial pressure between the four groups. Better post-resuscitation myocardial and cerebral function and longer duration of survival were observed in the VNS-treated animals. The protective effects of VNS could be abolished by MLA and imitated by GTS-21. In addition, VNS decreased the number of electrical shocks and the duration of CPR required. VNS improves multiple outcomes after CPR.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aconitine / analogs & derivatives*
  • Aconitine / pharmacology
  • Animals
  • Benzylidene Compounds / pharmacology*
  • Cardiopulmonary Resuscitation*
  • Male
  • Myocardial Reperfusion Injury* / parasitology
  • Myocardial Reperfusion Injury* / therapy
  • Myocardium / pathology
  • Pyridines / pharmacology*
  • Random Allocation
  • Rats
  • Rats, Sprague-Dawley
  • Vagus Nerve Stimulation*
  • alpha7 Nicotinic Acetylcholine Receptor / agonists*

Substances

  • Benzylidene Compounds
  • Pyridines
  • alpha7 Nicotinic Acetylcholine Receptor
  • methyllycaconitine
  • 3-(2,4-dimethoxybenzylidene)anabaseine
  • Aconitine