on August 24, 2009
Published online before print August 24, 2009, doi: 10.1161/CIRCULATIONAHA.109.853267
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Submitted on January 27, 2009
From Pulmonary and Critical Care Medicine, Department of Medicine, and Cerebral Vascular Disease Research Center, Department of Neurology, University of Miami Miller School of Medicine, Miami, Fla (C.D.); Hemostasis and Vascular Biology Research Institute (S.S., M.T.G.) and Department of Pharmacology and Chemical Biology (S.S.), University of Pittsburgh, Pittsburgh, Pa; University of North Carolina School of Medicine, Chapel Hill (A.P.); Emergency Resuscitation Center and Section of Emergency Medicine, University of Chicago, Chicago, Ill (D.G.B., T.L.V.H.); National Institute of Neurological Disorders and Stroke (J.P.M.) and National Heart Lung and Blood Institute Animal Imaging Core (S.A.A.), National Institutes of Health, Bethesda, Md; and Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pa (M.T.G.). * To whom correspondence should be addressed. E-mail: cdezfulian{at}med.miami.edu.
Background—Three-fourths of cardiac arrest survivors die before hospital discharge or suffer significant neurological injury. Except for therapeutic hypothermia and revascularization, no novel therapies have been developed that improve survival or cardiac and neurological function after resuscitation. Nitrite (NO2-) increases cellular resilience to focal ischemia/reperfusion injury in multiple organs. We hypothesized that nitrite therapy may improve outcomes after the unique global ischemia/reperfusion insult of cardiopulmonary arrest. Methods and Results—We developed a mouse model of cardiac arrest characterized by 12 minutes of normothermic asystole and a high cardiopulmonary resuscitation rate. In this model, global ischemia and cardiopulmonary resuscitation were associated with blood and organ nitrite depletion, reversible myocardial dysfunction, impaired alveolar gas exchange, neurological injury, and an Conclusion—Nitrite therapy after resuscitation from 12 minutes of asystole rapidly and reversibly modulated mitochondrial reactive oxygen species generation during early reperfusion, limiting acute cardiac dysfunction, death, and neurological impairment in survivors.
Accepted on June 30, 2009
Nitrite Therapy After Cardiac Arrest Reduces Reactive Oxygen Species Generation, Improves Cardiac and Neurological Function, and Enhances Survival via Reversible Inhibition of Mitochondrial Complex I
Cameron Dezfulian MD*,
50% mortality. A single low dose of intravenous nitrite (50 nmol=1.85 µmol/kg=0.13 mg/kg) compared with blinded saline placebo given at cardiopulmonary resuscitation initiation with epinephrine improved cardiac function, survival, and neurological outcomes. From a mechanistic standpoint, nitrite treatment restored intracardiac nitrite and increased S-nitrosothiol levels, decreased pathological cardiac mitochondrial oxygen consumption resulting from reactive oxygen species formation, and prevented oxidative enzymatic injury via reversible specific inhibition of respiratory chain complex I.
Key words: cardiopulmonary resuscitation • heart arrest • ischemia • nitric oxide • reperfusion
Related Article:
Circulation 2009 120: 823-824.