Catheter Guidance in the treatment of Ventricular Arrhythmias

Cardiac arrhythmias - changes in the regular beat of the heart - are one of the most prominent causes of morbidity in the developed world. Approximately 700,000 US citizens die each year from heart disease, and 60% to 65% of these cases are sudden and presumed to be caused by ventricular tachyarrhythmias (VT).

Radio Frequency Ablation (RFA) of cardiac arrhythmias requires the cardiologist to guide an ablation catheter to the site of the arrhythmia and to deliver a high-intensity radio-frequency current accurately to the exit site of a re-entrant circuit.

A new algorithm based on a single-equivalent moving dipole (SEMD) approximation of heart activity was recently identified by our lab that allows the non-invasive, potentially rapid detection of the origin of an arrhythmia using body-surface ECG signals. A successful implementation of this algorithm could make the RFA procedure accessible to many patients hitherto excluded.

We have designed and written software to implement the SEMD algorithm and to provide a graphical interface for the cardiologist during an RFA procedure. Further algorithmic improvements include a dipole-juxtaposition algorithm that has proven effective in computer simulations at guiding the catheter tip to the same location as the arrhythmic site to within 1 mm at any location within the model torso, even in the presence of distortion due to systematic error.

Work is currently being done to simulate the process of re-entry in the formation of post-myocardial infarction VT, and to produce a model of pacing ventricular tissue with a catheter tip.