Abstract 9: Total Liquid Ventilation Provides a Combined Neuro- and Cardioprotection After a Shockable Cardiac Arrest Occurring After Regional Myocardial Ischemia in Rabbits
Introduction: Total liquid ventilation (TLV) with perfluorocarbons has been shown to induce a rapid and protective cooling in animal models of cardiac arrest (CA). In these models, the heart was arrested without underlying myocardial ischemia.
Hypothesis: We assessed whether TLV could provide a combined neuro- and cardioprotection after a CA occurring after previous myocardial ischemia, as commonly observed in the clinical arena.
Methods: Rabbits instrumented with cardiac output (CO) probes were submitted to coronary artery occlusion. Two minutes later, ventricular fibrillation was induced and let untreated during 8 min. Rabbits were subsequently resuscitated and randomly submitted to a normothermic follow-up (Control) or 3 h of hypothermia (32°C) with either TLV or external cold blankets combined to saline infusion (30 ml/kg at 4°C i.v.; Saline group). Coronary artery reperfusion was instituted after 40 min of myocardial ischemia. After awakening, surviving rabbits were followed during 7 days.
Results: Ten rabbits were included and resuscitated in each group. Under cooling, the target tympanic and esophagus temperatures of 32°C were achieved within 5-10 min in TLV vs 30-45 min in Saline group. In the latter group, hypothermia failed to improve subsequent survival, CO or neurological recovery but slightly reduced infarct size vs Control (41±5% vs 54±3% of risk zone, respectively). Conversely, TLV potently reduced infarct size (13±1% of risk zone) and improved CO (e.g., 133±11 vs 84±19 ml/min/kg in survivors at day 1 in TLV vs Control, respectively). As shown in Figure, TLV also improved survival and neurological outcome.
Conclusions: Ultra-fast cooling with TLV induced a potent cardio- and neuroprotection in a rabbit model of CA with underlying myocardial ischemia, whereas conventional hypothermia was less efficient.
Left: Neurological dysfunction score (0%: normal; 100%: death). Right: survival after the cardiac arrest.*, p<0.05 vs Saline and Control
- © 2012 by American Heart Association, Inc.