[Changes in myocardial energy charge and energy metabolism following anoxic cardiac arrest and subsequent resuscitation].
This study was performed to evaluate the possibility of assisting cardiac resuscitation by measuring the energy level and myocardial function during cardiac arrest and subsequent resuscitation periods. The experiment was divided into 2 parts. In the first part, 36 rats were divided into 6 groups. Control rats were anesthetized only with pentobarbital and the heart was extirpated. Other rats were asphyxiated by ligating the trachea, and then the rats were divided into 5 groups according to the time of extirpation following cardiac arrest: 5, 10, 15, 20 and 30 minutes, respectively. The extirpated hearts were rapidly frozen with liquid nitrogen. ATP, ADP, AMP, creatine phosphate and adenosine were measured by high-performance liquid chromatography. Lactate was enzymatically measured and EC was calculated. ECG was monitored to ascertain complete electrical arrest. Disappearance of ECG activity was observed about 8 minutes after asphyxia. In the second part, 36 rats were also divided into 6 groups. After the same manipulation as in the first part, the extirpated heart was perfused for 30 minutes using Langendorff method and both cardiac function (LVP, LVdp/dt and HR) and EC were investigated. EC and ATP were already diminished at 1 minute and decreased progressively. On the contrary, total adenine nucleotide (TAN) was well maintained around control level until ECG activity disappeared completely, and an abrupt decrease in TAN occurred 20 minutes after the asphyxia. When the heart was perfused about 30 minutes, EC recovered to almost control level in the groups in which perfusion was started within 15 minutes, and its recovery was complete in the groups in which perfusion was begun after 15 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)
Kori
S
S
Department of Anesthesiology, Teikyo University School of Medicine, Tokyo.
D000818:Animals; D004734:Energy Metabolism; D006323:Heart Arrest / Q000209:etiology / Q000628:therapy*; D000860:Hypoxia / Q000150:complications*; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012151:Resuscitation