Mapping of supraventricular tachycardias by using a new tridimensional technology[mdash ]The CARTO system

Conventional mapping techniques use fluoroscopy and multiple catheters permitted knowledge of various mechanisms and precise definitions of the circuits involved is supraventricular tachycardias (SVT). Although radiofrequency catheter ablation (RFA) is highly effective in curing most of these arrhythmias, some cases might benefit from a more precise mapping technique. Recently new technology allowed construction of tridimensional mapping and real time non-fluoroscopic navigation through the heart chambers. The objective of this study is to report our initial experience using the CARTO system to map the circuits of different SVTs. We studied 17 patients, 11 with type 1 atrial flutter, 2 with AV nodal reentrant tachycardia (AVNRT), 3 patients with the Wolf-Parkinson-White syndrome (WPW) and 1 patient with atypical atrial flutter from the left atrium. Electroanatomic maps were constructed during the arrhythmia in 5/11 patients with flutter (in 6/11 the right atrial isthmus was mapped during coronary sinus pacing), in both patients with AVNRT and the one with atypical flutter. In patients with WPW maps from the respective AV annulus were obtained during atrial pacing with evident preexcitation. It was possible to define precisely the arrhythmia circuits in all patients. The right atrial isthmus was mapped in patients with type 1 atrial flutter, the atrial region corresponding to the nodal fast pathway was mapped and differentiated from the His bundle, coronary sinus and the slow pathway region in AVNRT patients, the AV ring corresponding to the accessory pathway was clearly shown (with successful RFA at this point), and the complex circuits involved in left atrial flutter were individualized. Successful RFA was performed in all patients, with recurrence of arrhythmia in the patient with atypical flutter and a non-isthmal atrial flutter in a patient with type 1 atrial flutter. We conclude that the CARTO system is highly effective in defining precisely the circuits involved in SVTs, being especially useful in complex cases in which a more precise mapping and navigation are necessary.