title: Differences of postresuscitation myocardial dysfunction in ventricular fibrillation versus asphyxiation.
abstract: OBJECTIVE
  This study aims to characterize postresuscitation myocardial dysfunction in 2 porcine models of cardiac arrest (CA): ventricular fibrillation cardiac arrest (VFCA) and asphyxiation cardiac arrest (ACA).
  
  
  METHODS
  Thirty-two pigs were randomized into 2 groups. The VFCA group (n = 16) were subject to programed electrical stimulation, and the ACA group (n = 16) underwent endotracheal tube clamping to induce CA. Once induced, CA remained untreated for 8 minutes. Two minutes after initiation of cardiopulmonary resuscitation (CPR), defibrillation was attempted until return of spontaneous circulation (ROSC) was achieved or animals died.
  
  
  RESULTS
  Return of spontaneous circulation was 100% successful in VFCA and 50% successful in ACA. Cardiopulmonary resuscitation duration in VFCA was about half as short as in ACA. The survival time of VFCA was significantly longer than that of ACA. Ventricular fibrillation cardiac arrest had better mean arterial pressure, cardiac output, and left ventricular ± dp/dt(max) after ROSC than ACA. Echocardiography revealed significantly lower left ventricular ejection fraction in ACA than in VFCA. Myocardial perfusion imaging using single-photon emission computed tomography demonstrated that myocardial injuries after ACA were more severe and widespread than after VFCA. Under a transmission electron microscope, the overall heart morphologic structure and the mitochondrial crista structure were less severely injured in the VFCA group than in the ACA group. Moreover, the percentage of apoptotic cardiomyocytes was higher in ACA than in VFCA.
  
  
  CONCLUSIONS
  Compared with VFCA, ACA causes more severe cardiac dysfunction associated with less successful resuscitation and shorter survival time.
authors.affiliation: Department of Emergency, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, 100020, China.
authors.forename: Cai-Jun
authors.initials: CJ
authors.lastname: Wu
authors.forename: Chun-Sheng
authors.initials: CS
authors.lastname: Li
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Qin
authors.initials: Q
authors.lastname: Yin
authors.forename: Chen-Chen
authors.initials: CC
authors.lastname: Hang
mesh_terms: D000818:Animals; D001237:Asphyxia / Q000150:complications / Q000473:pathology / Q000503:physiopathology*; D055426:Cardiac-Gated Single-Photon Emission Computer-Assisted Tomography; D009202:Cardiomyopathies / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D016887:Cardiopulmonary Resuscitation; D004195:Disease Models, Animal; D004452:Echocardiography; D004554:Electric Countershock; D006321:Heart / Q000000981:diagnostic imaging; D006323:Heart Arrest / Q000209:etiology / Q000628:therapy*; D046529:Microscopy, Electron, Transmission; D055414:Myocardial Perfusion Imaging; D009206:Myocardium / Q000473:pathology*; D011897:Random Allocation; D013318:Stroke Volume / Q000502:physiology; D015996:Survival Rate; D013552:Swine; D013997:Time Factors; D014693:Ventricular Fibrillation / Q000150:complications / Q000473:pathology / Q000503:physiopathology*