Characterizing fast pathway in typical and atypical atrioventricular nodal re-entrant tachycardia by atrial-His and His-atrial: more to consider.

volume is related to the surface area of contact between electrode tip and endocardium and that voltage-directed CTI ablation is an effective technique. Limited power delivery from using temperature control mode in the mini-electrode arm likely resulted from the location of the tip temperature sensor in this catheter. This, we believe, played a significant role in the less favourable outcome noted with this catheter. Caldwell et al. propose yet another possible mechanism whereby the contact area between ablative tip and tissue is inadvertently minimized as the operator attempts to optimize signal on the mini-electrode catheter as they nicely demonstrate in the attached figure. We thank the authors for their unique insight.