Abstract: Objective To investigate the expression of hyperpolarization-activated cyclic nucleotide-gated cation channel 4 （HCN4） and connexin43 （Cx43） in the sinoatrial node of electric shock death. Methods As experimental group, 34 cases of electric shock death who had definite current mark evidence were selected from pathology department of Xuzhou Medical College from 2010 to 2013. As the control group, 20 cases of fatal severe craniocerebral injury in traffic accidents were chosen. The expressions of HCN4 and Cx43 in the sinoatrial node were observed by immunohistochemical technology. Results HCN4 positive cells expressed in the cell membrane and cytoplasm of the sinoatrial node. Cx43 positive cells expressed in the cell membrane and cytoplasm of T cells and myocardial cells. The expression of HCN4 was significantly higher than that of the control group （P<0.05） and the expression of Cx43 was significantly lower than that of the control group （P<0.05）. Conclusion The changes of HCN4 and Cx43 expressions in the sinoatrial node illustrate electric shock death might be related to the abnormalities of cardiac electrophysiology and conduction.

Key words: forensic pathology, electric injuries, sinoatrial node, hyperpolarization-activated cyclic nucleotide-gated cation channel 4 （HCN4）, connexin43 （Cx43）