Global multielectrode contact-mapping plus ablation with a single catheter in patients with atrial fibrillation: Global AF study.

INTRODUCTION: The critical question for technological advancement of catheter ablation of atrial fibrillation (AF) is whether a creative new concept can combine and even improve the options of single-tip catheters with the simplicity of the use of balloon catheters. Herein are described the results from the first clinical study of a new multielectrode contact-mapping plus ablation array (Globe) offering such a complete solution. METHODS AND RESULTS: The multielectrode Globe array consists of 16 flat ribs with 122 gold-plated electrodes. Each electrode can record electrograms, ablate, pace, and can measure tissue contact and temperature. Single-shot pulmonary vein isolation (PVI) is possible with temperature-guided ablation of up to 24 electrodes simultaneously with automatic, individual power control of every electrode. Sixty patients with symptomatic AF underwent PVI using the Globe. In all sixty patients, acute PVI was achieved in 232 of 234 attempted PVs (99.1%). In 34 patients treated with "single-hot-shot" ablation, PVI was achieved in 136 of 136 PVs (100%). Single-procedure 12-month freedom from AF off antiarrhythmic drugs in the "single-hot-shot" group was 75.5% and freedom from AF/atrial tachycardia 72.3%. In two patients, pericardial tamponade was observed, one after a transseptal puncture, and one during array insertion with an over-advanced sheath. There were no other device-related serious adverse events, including stroke, PV stenosis, esophageal perforation, or phrenic nerve palsy. CONCLUSIONS: In this first clinical series, the Globe catheter was found to be an easy-to-use system for single-shot PVI. The continuously updated multielectrode voltage and activation mapping data indicate future options for mapping and ablation beyond PVI.

A novel ablation approach in atrial fibrillation patients undergoing fibrotic-based substrate modification: Targeting the Bachmann's bundle?

INTRODUCTION: Box isolation of fibrotic areas (BIFA) is a promising ablation approach for atrial fibrillation (AF) patients. However, complete isolation of fibrotic anteroseptal left atrial area, where Bachmann's bundle is blending into the left atrial myocardium, is very specific and complex. METHODS AND RESULTS: In 34 AF patients with anteroseptal fibrosis, circumferential BIFA was performed in addition to pulmonary vein isolation. In 8 of 34 patients, complete isolation of the fibrotic area was achieved with BIFA alone. In 26 of 34 patients, a decrease in voltage amplitude with or without conduction delay was observed after box ablation but no complete isolation. Activation mapping and characteristic unipolar potentials revealed earliest activation inside the box from one (73%), two (15%), or three (12%) remaining inputs, in the region of Bachmann's bundle insertion. Focal ablation inside the box (mean radiofrequency impulses: 1.7 ± 0.4, mean radiofrequency time: 70 ± 19 seconds) led to complete isolation of the fibrotic area in 25 of 26 patients. Overall, 97% of anteroseptal boxes were completely isolated with additional focal ablation in the study group compared to 21% in the control group with BIFA alone (33/34 vs. 7/34, P < 0.001). Time of left atrial activation decreased significantly by 25% after complete box isolation (P < 0.001). After a single procedure, 12-month arrhythmia-free survival was 82% with additional focal ablation compared to 71% in the control group (P = 0.2). CONCLUSION: Targeted and focal ablation in the region of Bachmann's bundle is a novel and feasible technique to achieve complete isolation of the left atrial anteroseptal fibrotic area.

Global multielectrode contact mapping plus ablation with a single catheter: Preclinical and preliminary experience in humans with atrial fibrillation.

INTRODUCTION: One question for the technological advancement of catheter ablation of atrial fibrillation (AF) is whether a creative new concept can combine and even improve the diagnostic mapping options of single-tip and basket catheters with the simplicity of the use of balloon catheters for ablation. Herein, we describe the first in-human experience with a single catheter offering such a complete solution. METHODS AND RESULTS: A new catheter (Globe® ) with a distal multielectrode array consisting of 16 ribs with 122 gold-plated electrodes was used. Each electrode can ablate, pace, and can measure tissue contact, temperature, current, and intracardiac electrograms. The Globe was deployed and removed without difficulty in all 3 patients. Complete pulmonary vein isolation (PVI) was achieved in all 12 veins. In 10 veins, PVI was achieved with a single placement in front of the respective vein ("single circle isolation"). In one subject, the device was repositioned due to the esophagus location. In the other subject, a single gap was observed after circumferential ablation of the right inferior PV. After precise gap identification, the device was adjusted slightly for improved contact at that region, and reablation resulted in immediate PVI. CONCLUSIONS: PVI isolation could be performed with the new multielectrode array Globe in all 12 PVs offering the option for easy handling and fast "single-shot" PVI. Several continuously updated mapping types from 122 electrodes even in real time during ablation demonstrate the capability to go beyond PVI for voltage mapping plus substrate modification, and for rotor mapping plus rotor ablation.

Box Isolation of fibrotic areas: A substrate modification approach in atrial fibrillation patients.

In the last years, atrial fibrosis was shown to be an independent predictor of procedural failure in patients with paroxysmal and persistent atrial fibrillation. Ablation strategies have been developed to improve the outcome of catheter ablation by targeting detected areas of fibrosis, based either on endocardial voltage mapping or cardiac magnetic resonance. Box isolation of fibrotic areas (BIFA) is a new and promising patient-tailored ablation strategy for atrial fibrillation patients targeting substantial fibrotic areas by circumferential isolation of left atrial fibrosis.