ウナギ体表心電図の単極導出法

抄録

Methods to record the ECGs from the skin of the eel, Anguilla japonica, were investigated. Monopolar recordings of the ECGs were successfully done, either when the fish was partly bathed, with the reference electrode placed in the water apart from the fish, or when an electrode designed similar to the WILSON's central terminal in human electrocardiography was used as the reference. Typically, QRS complex of the ECGs thus recorded was diphasic, being from negative to positive in the head region, and from positive to negative in the trunk region, while it showed triphasic or more complex patterns around the cardiac region. The amplitude was minimal at a dorsal position where the polarity of QRS reversed. In a fish held on a dry towel, the amplitude of QRS was almost constant over the whole surface except the vicinity of the heart. This indicates that even the tail is not the right place for the reference electrode in monopolar recording.