Disturbed expression and distribution of myocardial connexin 43 in sudden death patients with hyperthyroid heart disease

This study aimed to investigate the relationship between the expression and distribution of myocardial connexin 43 (Cx43) in the left ventricle and the incidence of sudden death due to hyperthyroid heart disease. Total 27 autopsy cases were selected from the Pathology Department of Medical School, Yangtze University from 2009 to 2014. The cases were divided into three groups (n=9): Experimental group, 6 males and 3 females, age range 20-57 years old, suddenly died of hyperthyroid heart disease; Hyperthyroid group, 7 males and 2 females, age range 27-63 years old; Control group, 5 males and 4 females, age range 27-49 years old. After pathological examination, Cx43 in the left ventricular muscle of each case was detected with immunohistochemical staining. In experimental group, Cx43 positive staining was found in the cytoplasm or side-side connection of ventricular myocardial cell, and the positive area and average optical density of Cx43 positive particles significantly decreased. In hyperthyroid group, average optical density of Cx43 positive particles decreased. In control group, Cx43 positive staining was found in the intercalated disc. In conclusion, the expression of myocardial Cx43 significantly decreased in sudden death patients with hyperthyroid heart disease. Our findings suggest that decreased expression of Cx43 may be related to sudden death of hyperthyroid heart disease.