Ventricular tachychardia (VT) is one of the mechanisms that induce sudden cardiac death. A way to cure VT is to ablate the exit site with an endocardial catheter. But it can be difficult, and sometimes impossible, to localize this exit site accurately enough. We propose a process to accelerate catheter ablation using an automatic method to guide the catheter towards the exit site. The proposed process uses the QRS complex integral of the 12-lead ECG. The method was tested using a realistic numerical forward model with pacing sites in endocardial, epicardial, and mid-myocardial tissue. With 12 pacing sites, 6 targets had been approximated to less than 1 mm. Five more were within 5 mm distance, and one was at 10 mm distance. We conclude that although the convergence is sometimes erratic, the proposed method does converge to the exit site, often within the radius of an ablation lesion.