Ventricular fibrillation during uniform myocardial anoxia due to asphyxia

Abstract

Thirty-three anesthetized dogs of varying weights were subjected to complete asphyxia by tracheal occlusion to produce uniform anoxia of the heart. Eleven showed electrocardiographic evidence of ventricular fibrillation while the other twenty-two demonstrated cardiac arrest. The development of ventricular fibrillation correlated with the heavier body and heart weights and with a lower average right atrial serum potassium level as compared to the dogs not fibrillating. Other serum electrolytes, pH, body temperature and sex showed no correlation with the arrhythmia. The importance of the fact that large dogs have a greater susceptibility to develop ventricular fibrillation during uniform anoxia of the heart is discussed in relation to experimental research on dogs and to a current theory of the cause of ventricular fibrillation.