Abstract 70: The Difference of Cardiac Mitochondrial Damage Between Ventricular Fibrillation and Asphyxial Cardiac Arrest
Background: Ventricular fibrillation and asphyxia account for vast majority of cardiac arrest. The course of cardiac arrest, neurological deficit and myocardial dysfunction differs between these two causes of cardiac arrest. However, the difference of cardiac mitochondrial damage between VF and asphyxial cardiac arrest remains unclear.
Hypothesis: The cardiac mitochondrial damage in VF cardiac arrest differs from that in asphyxial cardiac arrest.
Methods: The animals were equally randomized to asphyxia, VF and sham groups. In rats of VF group, VF was induced and untreated for 5 minutes, followed by 1 minutes of CPR, and then one electrical shock of 5 J. After the electrical shock, animals were sacrificed immediately. In the asphyxia group, cardiac arrest was induced by airway obstruction and maintained for 5 minutes, followed by 1minutes of CPR, and then sacrificed. The mitochondria were isolated from left ventricles for measurement of mitochondrial permeability transition pore (mPTP) opening and complex activity.
Results: The Glomori stain showed that both the asphyxial and VF cardiac arrest resulted in subsarcolemmal aggregation of mitochondria, suggesting mitochondrial damage. The rate of Ca2+-induced mitochondrial swelling in the asphyxia group was significantly faster than that of the VF group (p <.05)(Figure). The activity of NADH cytochrome c reductase decreased in the VF group when compared with the asphyxia and sham groups (VF:193.1±24.1, asphyxia: 232.7±48.1, sham: 235.4±47.5 nmol/min/mg protein, p <.05).The activity of cytochrome c oxidase decreased significantly in both the VF and asphyxia groups (VF:0.33±0.06, asphyxia:0.28±0.07, sham:0.35±0.07unit/mg), especially in the asphyxial cardiac arrest (p <.05 between asphyxia and VF groups).
Conclusions: Both VF cardiac arrest and asphyxial cardiac arrest cause cardiac mitochondrial damage. There is difference of mitochondrial damage between these two models of cardiac arrest.
- © 2010 by American Heart Association, Inc.