Magnetoelectroanatomic mapping of arrhythmias in structural heart disease using a novel multielectrode catheter:

Electroanatomic mapping with CARTO requires point-by-point acquisition using the mapping catheter's bipolar tip electrode. This study evaluates the utility of a novel 26-electrode catheter (Qwikstar) for electroanatomic mapping of arrhythmias in patients with structural heart disease. The multielectrode catheter acquires activation times and anatomic data simultaneously from its tip and shaft electrodes. Eight patients (6 men, 2 women, age 47 years [37, 65]) with atrial tachycardia (n = 6) and ventricular tachycardia (n = 2) due to congenital heart disease (n = 4) and cardiomyopathy (n = 4) were studied. Using the multielectrode catheter, the electroanatomic map was constructed in two stages: (1) a scout map using the minimum number of tip and shaft electrode data points that covered > 70% of the tachycardia cycle length and/or the majority of the chamber volume, and (2) a complete map using additional tip electrode data points. A total of 36 (28, 510) tip electrode and 38 (34, 42) shaft electrode electroanatomic data points comprised the scout map. The complete map was constructed with a total of 102 (73, 134) tip electrode electroanatomic data points. In three patients, the scout map suggested a cavotricuspid isthmus dependent atrial flutter that was confirmed with the complete map. In another four patients, the scout map identified the earliest site of focal activation, which was also confirmed with the complete map. In comparison, activation mapping using the bipolar catheter (Navistar) in a group of arrhythmia-matched control subjects required 210 (180, 320) electroanatomic data points (P = 0.012 vs multielectrode catheter complete map). In conclusion, for large macroreentrant or focal arrhythmias in patients with structural heart disease, the multielectrode catheter can generate a scout map that accurately guides complete electroanatomic mapping using fewer point-by-point acquisitions than the bipolar catheter.