RESUMO
BACKGROUND: Cold static storage and normothermic ex vivo heart perfusion are routinely limited to 6 h. This report describes intermittent left atrial (LA) perfusion that allows cardiac functional assessment in a working heart mode. METHODS: Using our adult porcine model, general anesthesia was induced and a complete cardiectomy was performed following cardioplegic arrest. Back-table instrumentation was completed and normothermic ex vivo heart perfusion (NEHP) was initiated in a nonworking heart mode (Langendorff). After 1 h of resuscitation and recovery, LA perfusion was initiated and the heart was transitioned to a coronary flow-only working heart mode for 30 min. Baseline working heart parameters were documented and the heart was returned to nonworking mode. Working heart assessments were performed for 30 min every 6 h for 24 h. RESULTS: Twenty-four-hour NEHP on 9 consecutive hearts (280â ±â 42.1 g) was successful and no significant differences were found between working heart parameters at baseline and after 24 h of perfusion. There was no difference between initial and final measurements of LA mean pressures (5.0â ±â 3.1 versus 9.0â ±â 6.5 mm Hg, P â =â 0.22), left ventricular systolic pressures (44.3â ±â 7.2 versus 39.1â ±â 9.0 mm Hg, P â =â 0.13), mean aortic pressures (30.9â ±â 5.8 versus 28.1â ±â 8.1 mm Hg, P â =â 0.37), and coronary resistance (0.174â ±â 0.046 versus 0.173â ±â 0.066 mL/min/g, P â =â 0.90). There were also no significant differences between lactate (2.4â ±â 0.5 versus 2.6â ±â 0.4 mmol/L, P â =â 0.17) and glucose (173â ±â 75 versus 156â ±â 70 mg/dL, P â =â 0.37). CONCLUSIONS: A novel model using intermittent LA perfusion to create a coronary flow-only working heart mode for assessment of ex vivo cardiac function has been successfully developed.
