Objective  To evaluate the effect and mechanism of brain death on cardiac injury in pig models established by gradually increasing intracranial pressure.

  Methods  Sixteen Wuzhishan miniature pigs were randomly divided into the experimental and sham surgery groups. In the experimental group, animal models with brain death were established by increasing intracranial pressure. In the sham surgery group, merely cranial catheterization was performed. The changes in the electrocardiogram(ECG) were monitored before and after surgery. The variations of the serum levels of creatine kinase (CK), creatine kinase isoenzyme (CK-MB) and lactate dehydrogenase (LDH) were quantitatively measured before and at 0, 3, 6, 12 h after surgery

  Results  Along with the duration of brain death, decline of ECG amplitude and elevation in T-wave amplitude were observed. At 0, 3 and 6 h after surgery, the levels of CK in the experimental group were significantly higher than those in the sham surgery group (all P < 0.05). At 6 and 12 h after surgery, the CK-MB levels in the experimental group were considerably higher than those in the sham surgery group (all P < 0.05). At postoperative 0, 3, 6 and 12 h, the levels of CK and CK-MB in the experimental group were enhanced compared with preoperative levels (all P < 0.05). However, the LDH levels at 0, 6 and 12 h after surgery were significantly lower than preoperative levels in the sham surgery group (all P < 0.05)

  Conclusions  Brain death pig models present with specific changes in ECG under the status of brain death, probably related to the myocardial damage.