Abstract:

BACKGROUND: Presently, simple cryopreservation is widely used in preserving donor heart. However, it can not transport for a long distance due to 4-6 hours safe duration, which would affect the effective application of donor heart. Thus, it is necessary to explore methods for heart preservation in a beating state.
OBJECTIVE: To establish a cardiopulmonary bypass model of the heart preservation in a beating state, and to provide a laboratory basis for the beating heart.
METHODS: A total of 12 adult Bama miniature pigs, weighing 25-30 kg, were randomly allocated into 2 groups. In the experimental group, the isolated rat heart were induced warm oxygenated blood by the bypass circuit (blood blow 60-80 mL per minutes), the heart preservation in a beating state for 8 hours. In the control group, heart was preserved in hypothermia UW solution for 8 hours. Physiological recorder was used to observe the changes of beating heart rate and the perfusion pressure. Hourly blood samples were taken for arterial blood gases and serum electrolytes parameter. After 8 hours, ATP and cardiac ultrastructure of donor heart were detected.
RESULTS AND CONCLUSION: ①Transient 2:1 atrioventricular block occurred in a pig, and remained donor hearts were successfully preserved in a beating state in the experimental group. ②During preservation, perfusion pressure was not rising. The value of pH and BE in blood were gradually decreased. The value of serum potassium and serum calcium gradually increased in the experimental group. ③The levels of myocardial ATP in the experimental group was significant greater than the control group (P < 0.05). ④There were few mitochondrion swelling and myocardial ultrastructures were similar to the normal state in the experimental group. However, the myocardium was swelling and vacuolar degeneration could be found in the control group. Preservation donor heart with cardiopulmonary bypass in a beating state is feasible. The cardiopulmonary bypass has its own features.