Development of isolated swine "working heart model" with parabiotic circulation

Objective: To develop an isolated working heart model with parabiotic circulaton in swines and verify its stability and possibility to allow effective measurements of hemodinamic and metabolic data. Methods: This model was developed during study of association of agents to cardiolegia. There were performed 18 experiments, each with a support animal and a donor animal. Donor animal heart was perfused as isolated working heart with parabiotic circulation from support animal. Isolated heart underwent regional ischemia by interventricular artery clamping, followed by global ischemia. During reperfusion in working heart state mode at 30, 60 and 90 minutes, contractility indices such as elastance, preload recruitable stroke work index and metabolic data were acquired. Results: Support animals were kept stable throughout the procedures without use of blood transfusions or vasoactive drugs. pH, oxygen partial pressure and hematocrit were kept stable and within physiologic ranges. Isolated heart was perfused adequately throughout the experiment. All hemodinamic and metabolic data proposed were adequately measured in working heart state mode. Conclusion: This swine isolated "working heart" model was kept stable throughout the experiments with no administration of vasoactive drugs and it allowed adequate measurements of metabolic and hemodinamic data.231142