Funny current and sudden cardiac death

HCN4 is considered the main channel involved in spontaneous depolarization of the sinus node cells, which underlies the formation of normal cardiac sinus rhythm. Structural and functional characteristics have been extensively studied, revealing the location, its synthesis and regulation. Its dysfunction causes supraventricular/ ventricular arrhythmias (some lifethreatening) and is involved in the pathogenesis of heart disease. In this study we investigated this channel expression in the sinus node from cadaveric heart with future utility to histopathological diagnosis of sudden cardiac death. We found that HCN4 is expressed at mRNA and protein level in the sinus node from cadaveric hearts and its expression correlates with expression of TBX3 (transcription factor that controls HCN4 expression).