As for this invention, the balloon equipped ablation catheter it is possible, collectively to insert in heart intracavity, high frequency current turning on electricity, preventing the abnormal heat generation of the electrode for electric potential measurement is possible, it designates that it offers the catheter for electric potential measurement whose safety is high as purpose. As for this invention, the lumen which from the metal section where the electrode and length for electric potential measurement is above 2mm and the proximal edge in longitudinal direction is penetrated to the distal (2036) edge and, it passes by the shaft and the above-mentioned lumen which it possesses, the metal wire which is connected to the above-mentioned metal section and, it has, the catheter for electric potential measurement is offered.本発明は、バルーン付きアブレーションカテーテルと併せて心腔内に挿入することが可能であり、高周波電流を通電しても電位測定用電極の異常発熱を防止することのできる、安全性の高い電位測定用カテーテルを提供することを目的としている。本発明は、電位測定用電極と、長さが2mm以上ある金属部と、長手方向における近位端から遠位端に貫通するルーメンと、を有するシャフトと、上記ルーメンに挿通され、上記金属部に接続されている金属ワイヤーと、を備える、電位測定用カテーテルを提供する。
