A method of treating cardiac arrhythmia, including guiding a distal end portion of a catheter, the distal end portion having a distal tip and accommodating at least one elongated ablation electrode into a desired intracardiac region, for example, from the inferior vena cava into the right atrium of a human heart, and then from the right atrium into the right ventricle of the heart, pulling the catheter backwards, for example, towards the inferior vena cava, until the distal tip engages a edge of an intracardiac orifice, for example, the tricuspid annulus whereby the at least one ablation electrode engages a target tissue, for example, the isthmus of tissue between the tricuspid annulus and the inferior vena cava, deflecting the distal tip into a hook-shaped configuration, and activating the at least one ablation electrode to produce a substantially continuous lesion on the target tissue.