Abstract: Objective　To compare re-beating effect after preservation and transplantation of isolated rabbit heart with simple low temperature immersion, continuous or intermittent perfusion of Histidine-tryptophan-ketoglutarate (HTK) solution.　Methods　36 healthy New Zealand rabbits, with 2 months old, with mean weight 2.15 kg , were chosen and divided randomly into the following three groups: a simple low temperature immersion group (simple group, n=10), a continuous group (n=10) and an intermittent 2h perfusion (intermittent group, n=16). The rabbits were taken out the isolated heart after anesthetization to establish HTK solution through aortic root, the hearts were suspended on Langendorff perfusion model. K-H buffer solution was perfused for 5~10 minutes to stable heart pulsation. HTK solution was perfused about 5 ~ 6 ml (30ml/kg) according to the grouping to store heart at 4 ℃ for 8 hours. Then pressure transducer and coronary effluent were collected  Cardiac resuscitation time, the difference of myocardial histomorphology and other related indexes among the three groups were compared.　Results　The isolated hearts were re-beating successfully in the three groups. The resuscitation time, arrhythmia score after 1 minute and 5 minutes, average heart rate, arrhythmia incidence and time of epinephrine injections in the intermittent group were all significantly lower than those of the continuous group and the simple group (P<0.05). CK-MB and cTnI levels in the intermittent group were less than those of the continuous group and the simple group (P<0.05). The LVSP and CSF values after re-beating 5min in the intermittent group were higher than those of the continuous group and the simple group (P<0.05). The degrees of myocardial cellular edema and inflammatory cell infiltration in the intermittent group were the lowest, but the above indexes in the simple group were the highest.　Conclusions　Intermittent 2 hours perfusion of HTK solution may be more effective in reducing arrhythmia and myocardial injury, improving left ventricular hemodynamics after cardiac resuscitation in isolated rabbit hearts than continuous perfusion or simple hypothermic immersion, which is expected to be a simple, efficient and safe method for preserving transplanted hearts.

Key words: Histidine-tryptophan-ketoglutarate solution, 　Intermittent perfusion, 　Transplantation, Re-beating, 　Arrhythmia, 　Creatine kinase isoenzymes, 　Troponin I, 　Hemodynamics