Total Liquid Ventilation Provides Ultra-Fast Cardioprotective Cooling

ObjectivesWe tested whether total liquid ventilation (TLV) can be used to rapidly cool and protect the infarcting heart.BackgroundDecreasing myocardial temperature during ischemia is a powerful cardioprotective strategy, but clinical application has been impaired by lack of practical methodology to quickly cool the heart.MethodsWe performed 30-min coronary artery occlusion/3-h reperfusion in rabbits. Upon occlusion, rabbits underwent either oxygen (Gas), normothermic liquid (Liquid Warm), or cold liquid (Liquid Cool) ventilation.ResultsLeft atrial chamber temperature decreased to 32.4° ± 0.2°C within 5 min of onset of cold TLV. Blood gases were within acceptable limits during TLV. In the Liquid Warm group, perfluorocarbon inhalation did not alter infarct size compared with Gas (37.7 ± 1.3% and 42.5 ± 4.9% of risk zone, respectively). However, infarction was significantly reduced in the Liquid Cool group (4.0 ± 0.5%). Cooling only during the initial 30 min of reperfusion did not reduce infarction.ConclusionsTotal liquid ventilation can elicit rapid cardioprotective cooling during ischemia.