High-precision guidance of ablation catheters to arrhythmic sites using electrocardiographic signals.

Hemodynamically unstable ventricular arrhythmias are frequently untreatable with radio-frequency ablation due to the difficulty of rapidly and accurately localizing the site of origin of an arrhythmia with current technologies. We demonstrate a new catheter guidance method that will direct the tip of an ablation catheter to the site of origin of an arrhythmia and reduce the time needed to locate the site such that a patient need only be maintained in the arrhythmia for a few beats. The algorithm, based on a single-equivalent moving dipole (SEMD) model, is used to identify the bioelectric dipole corresponding to a site of origin of an arrhythmia. If a current dipole is produced at the ablation catheter tip, the tip position may also be calculated using this algorithm, and the catheter can be guided towards the site of origin of the arrhythmia. We present a method to compensate for the effect of systematic non-idealities, such as boundary effects, on the accuracy of this algorithm. In simulations, this method is able to guide the catheter tip to within 1.5 mm of the arrhythmic site at any location within the model torso with almost 100% success and with a realistic number of movements of the ablation catheter. These results suggest that this method has great potential to direct radio-frequency ablation procedures, especially in the significant patient population that is currently untreatable.