Clin Res Cardiol (2021). 10.1007/s00392-021-01933-9

First-in-Man very high-power short-duration temperature-controlled ablation of anterior line utilizing an open-irrigated abaltion catheter with microelectrodes to treat macroreentry atrial tachycardia
C.-H. Heeger1, J. Vogler1, B. Kirstein2, C. Eitel2, K.-H. Kuck3, R. R. Tilz1
1Medizinische Klinik II / Kardiologie, Angiologie, Intensivmedizin, Universitätsklinikum Schleswig-Holstein, Lübeck; 2Med. Klinik II / Kardiologie, Elektrophysiologie, Universitätsklinikum Schleswig-Holstein, Lübeck; 3Kardiologie, LANS Cardio Hamburg, Hamburg;
Catheter ablation has proven high procedural success and encouraging long-term follow-up for patients with atrial fibrillation (AF). Recently a novel contact force (CF) sensing catheter (QDOT Micro, Biosense Webster, Inc. Diamond Bar, CA, USA) has been developed allowing temperature-controlled very high-power short duration (vHP-SD) ablation of 90 Watts for 4 seconds (QMODE+ ablation mode). It incorporates three microelectrodes and six thermocouples at the tip for precise temperature monitoring.
Until today no evaluation of additional lesions beside PVI has been reported. However, vHP-SD ablation might be an efficient ablation technique for linear lesion deployment beyond PVI and the microelectrodes might offer unique findings during atrial tachycardia (AT) mapping and ablation. Here we present the first-in-man treatment of a perimitral AT by ablation of an anterior line solely utilizing the vHP-SD QMODE+ mode of the QDOT Micro catheter.

A 74 year old male patient presented in the emergency care unit with dyspnea, palpitations and persistent tachycardia (EHRA class IIb).
Further pre-existing disease were recurrent PersAF and typical atrial flutter since >5 years despite antiarrhythmic drug therapy with flecainide (2x100mg). The 12-lead ECG showed a heart rate of 105 / min with small regular p-waves suggesting an AT.
After informed consent the patient was scheduled for an ablation procedure. At the beginning of the the procedure the patient presented the clinical AT (cycle length, CL=300ms).
Three-dimensional electroanatomic LA reconstruction (CARTO 3 V7; Biosense Webster) was performed via fast anatomical mapping with a multi-electrode spiral mapping catheter. A total of 6590 mapping points were aquired utilizing a local activation time map with a window of interest of -145ms / +145ms and the complete CS electrodes (center of energy) as reference.
After mapping a perimitral atrial tachycardia with a potential critical isthmus at the anterior wall was demonstrated. Therefore and due to the massive scar area at the LA anterior wall an ablation of an anterior line was conducted. For all applications vHP-SD ablation was performed. For anterior lesions we aimed an inter-lesion distance of 3-4 mm while for posterior lesions an inter-lesion distance of 5-6mm was used. The CF target range was 10-20g. Within the zone of slow conduction fragmented potentials were detected at the microelectrodes while no signals were detected on the standard electrodes. During the third vHP-SD application the CL was prolonged from 300ms to 400ms after less than 1 second application time (total RF time: 12 seconds). The anterior line was continued until the anterior mitral annulus. The 10th application was started and the AT was terminated after less than 1 second application time (total RF time: 40 seconds). Afterwards the anterior line was completed by a total of n=29 vHP-SD applications and a total RF time of 116 seconds, connecting the anterior mitral annulus to the antero-superior aspect of the right superior pulmonary vein (PV). No steam pops occurred during the procedure and no charring was visible on the ablation catheter tip at the end of the procedure.


Here we present a case of AT ablation utilizing the QDOT Micro catheter. Our findings highlight the benefit of utilizing microelectrodes during AT ablation. Furthermore we prove the concept of vHP-SD for ablation of LA linear lesions.