A method for guiding ablation catheters to arrhythmogenic sites using body surface electrocardiographic signals.

Treatment of hemodynamically unstable ventricular arrhythmias requires rapid and accurate localization of the reentrant circuit. We have previously described an algorithm that uses the single-equivalent moving dipole model to rapidly identify both the location of cardiac sources from body surface electrocardiographic signals and the location of the ablation catheter tip from current pulses delivered at the tip. However, during catheter ablation, in the presence of sources of systematic error, even if the exit site and catheter tip dipole are superposed in real space, their calculated positions may be separated by as much as 5 mm if their orientations are not exactly matched. In this study, we present a method to compensate for the effect of dipole orientation and examine the method's ability to guide a dipole at a catheter tip to an arrhythmogenic dipole corresponding to the exit site. In computer simulations, we show that the new method enables the user to guide the catheter tip to within 1.5 mm of the arrhythmogenic dipole using a realistic number of movements of the ablation catheter. These results suggest that this method has the potential to greatly facilitate RF ablation procedures, especially in the significant patient population with hemodynamically unstable arrhythmias.