The ECG abnormalities were commonly sinus bradycardia, ST-T changes, and myocardial ischemia while others mainly included premature beat, arrhythmia, conduction block, abnormal Q waves, and so on.

Results The total ECG abnormal rate, sinus bradycardia and sinus arrhythmia in the exposed group were significantly higher than those of the control group(P<0.01, or P<0.05).

Cardiac arrhythmia, bradycardia or other serious symptoms were not observed during the process of hypothermia.