Remodeling of K(v)1.5 Channel in Right Atria from Han Chinese Patients with Atrial Fibrillation

BACKGROUND: The incidence of atrial fibrillation (AF) in rheumatic heart diseases (RHD) is very high and increases with age. Occurrence and maintenance of AF are very complicated process accompanied by many different mechanisms. Ion-channel remodeling, including the voltage-gated potassium channel K(v)1.5, plays an important role in the pathophysiology of AF. However, the changes of K(v)1.5 channel expression in Han Chinese patients with RHD and AF remain poorly understood. The aim of the present study was to investigate whether the K(v)1.5 channels of the right atria may be altered with RHD, age, and sex to contribute to AF. MATERIAL/METHODS: Right atrial appendages were obtained from 20 patients with normal cardiac functions who had undergone surgery, and 26 patients with AF. Subjects were picked from 4 groups: adult and aged patients in normal sinus rhythm (SR) and AF. Patients were divided into non-RHD and RHD groups or men and women groups in normal SR and AF, respectively. The expression of K(v)1.5 protein and messenger RNA (mRNA) were measured using Western blotting and polymerase chain reaction (PCR) method, respectively. RESULTS: Compared with the SR group, the expression of K(v)1.5 protein decreased significantly in the AF group. However, neither K(v)1.5 protein nor KCNA5 mRNA had significant differences in adult and aged groups, non-RHD and RHD group, and men and women group of AF. CONCLUSIONS: The expression of K(v)1.5 channel protein changes with AF but not with age, RHD, and sex in AF.