A catheter for mapping and/or ablating a region of the heart, comprises a catheterbody with an intermediate section that is connected to a tip assembly by a highlyflexible preshaped section. The highly flexible section presets the tip assemblyat an off axis and/or off plane angles from the intermediate section, to providethe following: a) The intermediate section when deflected approximates thegenerally convex region of the cavo tricuspid isthmus and the preset angle ofthe flexible section is off axis in the same plane and same direction as deflectionof the intermediate section to enable the tip assembly to contact the cavo tricuspidisthmus for ablation and/or mapping. b) The intermediate section when deflectedapproximates the generally concave region of the VA/RV/LA/LV and the presetangle in the same plane and opposite direction of deflection enables the tip assemblyto contact the walls of the cavity for ablation and/or mapping. c) The intermediatesection when deflected approximates the generally convex region of the His areaand the preset off plane angle of the flexible section enable the tip assemblyto contact the Bundle of His region. A high bending modulus of the flexible sectionenables the flexible section to absorb displacement force applied to the tipassembly, such as when the tip assembly encounters uneven tissue surface, withoutdisplacing the intermediate section. The flexible section prevents excessiveforce from being applied to the tip assembly, reducing the risk of any of the following:a) mechanical perforation, b) steam pop, c) burying the tip assembly in the myocardiumresulting in high temperatures, low energy delivery, thrombus formation andchar formation.
