An intracardiac catheter for ultrasound guided ablation and EP mapping. Ablation and mapping electrodes 34, 36, 38, 39 are carried on the surface of an outer catheter 30 and an ultrasound array is mounted inside an inner catheter 20. Backloading the inner catheter into the outer catheter provides the ultrasound array in position to image tissue near the surface electrodes. An acoustic coupling fluid is provided between the catheters and a number of the electrodes 34, 38 are positioned directly within the image field of the array.
