Improved survival and reduced myocardial necrosis with cardiopulmonary bypass reperfusion in a canine model of coronary occlusion and cardiac arrest.
OBJECTIVE
Does cardiopulmonary bypass (CPB) improve resuscitation rates and limit infarct size after cardiac arrest and acute myocardial infarction?


METHODS
Controlled randomized trial with all animals undergoing left anterior descending coronary artery occlusion and subsequent ventricular fibrillation and resuscitation. All animals were supported for four hours after resuscitation in an intensive care setting.


METHODS
Group 1 (eight) was resuscitated with standard external CPR and advanced life support. Group 2 (eight) was resuscitated with CPB.


RESULTS
Group hemodynamic, resuscitation variables, number resuscitated, and number of four-hour survivors were compared. Ischemic and necrotic myocardial weights were determined with histochemical staining techniques in four-hour survivors. Infarct size was measured as the ratio of necrotic weight to ischemic weight. Significantly fewer dogs were resuscitated in group 1 (four of eight) than in group 2 (eight of eight) (P less than .05). Group 2 survivors required significantly less epinephrine and lidocaine than group 1 survivors (P less than .05) and higher aortic diastolic and coronary perfusion pressures after CPB (P less than .001). The ratio of myocardial necrotic weight to ischemic weight at four hours was 0.82 +/- 0.25 in group 1 and 0.22 +/- 0.25 in group 2 (P less than .05). However, collateral blood flow was not measured in this study.


CONCLUSIONS
This pilot study further substantiates the improvement in resuscitation rates obtainable with CPB. CPB may also limit infarct size during the postresuscitation period and requires further study.
Angelos
M G
MG
Department of Emergency Medicine, Wright State University School of Medicine, Dayton, Ohio 45401-0927.
Gaddis
M L
ML
Gaddis
G M
GM
Leasure
J E
JE
D000818:Animals; D002315:Cardiopulmonary Bypass; D003327:Coronary Disease / Q000150:complications / Q000401:mortality / Q000628:therapy*; D004285:Dogs; D004554:Electric Countershock; D004837:Epinephrine / Q000627:therapeutic use; D006323:Heart Arrest / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D006439:Hemodynamics; D008012:Lidocaine / Q000627:therapeutic use; D008955:Models, Cardiovascular; D015425:Myocardial Reperfusion; D010865:Pilot Projects; D011897:Random Allocation; D012151:Resuscitation / Q000379:methods*
D008012:Lidocaine; D004837:Epinephrine