Clinical experience with a novel multielectrode basket catheter in right atrial tachycardias

Background-The complexity of atrial tachycardias (ATs) makes the electroana tomic characterization of the arrhythmogenic substrate difficult with conve ntional mapping techniques. The aim of our study was to evaluate possible a dvantages of a novel multielectrode basket catheter (MBC) in patients with AT. Methods and Results-ln 31 patients with AT, an MBC composed of 64 electrode s was deployed in the right atrium (RA). The possibility of deployment, spa tial relations between MBC and RA, MBC recording and pacing capabilities, m apping performance, and MBC-guided ablation were assessed. MBC deployment w as possible in all 31 patients. The MBC was left in the RA for 175+/-44 min utes. Stable bipolar electrograms were recorded in 88+/-4% of electrodes. P acing from bipoles was possible in 64+/-5% of electrode pairs. The earliest activity intervals, in relation to P-wave onset, measured from the MBC and standard roving catheters were 41+/-9 and 46+/-6 ms, respectively (P=0.21) . Radiofrequency ablation was successful in 15 (94%) of 16 patients in whom it was attempted, including 2 patients with polymorphic right atrial tachy cardia (RAT), 2 with RAT-atrial nutter combination, 1 with macroreentrant A T, and 1 with focal origin of atrial fibrillation. Conclusions These data demonstrate that MBC can be used safely in patients with right atrial arrhythmias. The simultaneous multielectrode mapping aids in the rapid identification of sites of origin of the AT and facilitates r adiofrequency ablation procedures. The technique is especially effective fo r complex atrial arrhythmias.