Radiofrequency catheter ablation of fascicular tachycardia using a non-contact mapping system

Fascicular ventricular tachycardia (FVT) is a well recognised tachycardia mechanism arising from the LV. We report the use of a non-contact multielectrode array (MEA) to construct isopotential maps of the left ventricular endocardial activation pattern during fascicular tachycardia in 3 pts (2m aged 34, 48, and 54yrs). The MEA allows reconstruction of 3360 unipolar electrograms which are superimposed on a 3-dimensional model of the LV. The earliest activation point on the LV endocardium during tachycardia was identified. Using a combination of fluoroscopy and software which allows ablation catheter-tip localisation relative to the isopotential map {MEA reference electrodes) a standard RF ablation catheter tip was manipulated to that point. In all 3 pts a fascicular potential was identified at that site. Application of radiofrequency energy to the site lead to abolition of FVT which remained non-inducible for 1 hour after RF application. Procedure times were 67, 78 and 98 mins. Fluoroscopy times were 20, 22 and 25 mins. Conclusion: Non-contact mapping of FVT facilitates rapid and successful RF catheter ablation of this tachycardia substrate.