Outcomes of CPR in the presence of partial occlusion of left anterior descending coronary artery.
OBJECTIVE
To develop a clinically relevant experimental model of cardiac arrest and CPR in which a partial occlusion of the left anterior descending coronary artery (LAD) is maintained during the resuscitation procedure and the initial post-resuscitation interval.


METHODS
Ventricular fibrillation (VF) was induced by LAD occlusion with a balloon tipped catheter in 16 domestic male pigs weighing 41+/-2kg. After a 7min interval of untreated VF, the LAD balloon occlusion was deflated and the catheter withdrawn in eight animals. The LAD balloon was deflated in the remaining eight animals but the catheter was kept in place in order to maintain a partial occlusion of the LAD, which was approximately 75% of the internal lumen. CPR, including chest compressions and ventilations with oxygen, was then performed for 2min before a defibrillation attempt. Thirty minutes following successful resuscitation the LAD catheter was withdrawn in the animals with partial occlusion of the LAD.


RESULTS
In the animals that had the LAD totally unoccluded before to starting CPR, each animal was resuscitated successfully and survived for more than 72h with better neurological recovery during the initial 24h post-resuscitation than did the partially occluded group. When a partial occlusion of the LAD was maintained during CPR, six of eight animals were resuscitated and only four of these survived for 72h. A significantly greater number of electrical shocks prior to ROSC were required when a partial occlusion of the LAD was maintained during CPR. Significantly greater severity of post-resuscitation myocardial dysfunction was observed in animals resuscitated with a partial occlusion of the LAD.


CONCLUSIONS
In this model of prolonged untreated cardiac arrest, maintaining a partial occlusion of the LAD during CPR and the initial post-resuscitation interval required a greater number of shocks before ROSC, increased severity of post-resuscitation myocardial dysfunction significantly and yielded less favourable outcomes.
Ristagno
Giuseppe
G
Weil Institute of Critical Care Medicine, Rancho Mirage, CA, United States.
Tang
Wanchun
W
Xu
Ting Yan
TY
Sun
Shijie
S
Weil
Max Harry
MH
D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D023921:Coronary Stenosis / Q000150:complications*; D004195:Disease Models, Animal; D006323:Heart Arrest / Q000209:etiology / Q000401:mortality / Q000628:therapy*; D008297:Male; D015996:Survival Rate; D013552:Swine; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000150:complications / Q000628:therapy