Impact of high-resolution 3D-mapping with micro-electrodes on catheter ablation of Wolff-Parkinson-White syndrome.

Background: It is currently unknown whether high-resolution 3D-mapping and micro-electrodes add meaningful benefits in catheter ablation of Wolff-Parkinson-White (WPW) syndrome and challenging, e.g. para-Hisian accessory pathways (APs). Objectives: To compare the mapping resolution, acute success and complication rates in patients with WPW syndrome undergoing a first-time catheter ablation using only a contact force-sensing ablation catheter for mapping or a multi-electrode high-resolution mapping catheter. Methods: Fifty consecutive 3D-mapping procedures for WPW syndrome using a 3.5-mm ablation catheter (n = 27) or a multi-electrode high-resolution catheter (n = 23) were retrospectively analyzed regarding mapping resolution defined as first 5/10 msec isochronal activation area, number of RF applications to achieve AP block, occurence of AP automaticity during RF delivery, and acute success and complication rates. Results: Catheter ablation was successful in 48/50 patients with a median of 1 (IQR 1-2) RF applications. Compared to ablation catheter mapping, high-resolution mapping showed a significantly smaller isochronal activation area in the first 5/10 msec (1.25 ± 0.29 vs 0.15 ± 0.03 cm2; P < 0.001 and 3.41 ± 0.58 vs 0.55 ± 0.12 cm2; P < 0.0001) and significantly higher incidence of AP automaticity during RF delivery (0 vs 22 %; P < 0.05). In para-Hisian APs, micro-electrodes recorded distinct His electrograms and AP potentials without fusion and without AP bumping permitting safe and effective para-Hisian AP ablation. Conclusions: High-resolution mapping increases the mapping accuracy of the AP and its insertion site leading to a significantly higher incidence of AP automaticity during RF delivery. Micro-electrodes provide clinically relevant advantages in para-hisian AP mapping improving efficacy and safety of para-Hisian AP ablation.

Initial Clinical Experience With a Novel 8-Spline High-Resolution Mapping Catheter.

BACKGROUND: The Octaray (Biosense Webster) is a novel, multispline mapping catheter with 48 closely spaced microelectrodes enabling high-resolution electroanatomical mapping. OBJECTIVES: This study sought to report the initial clinical mapping experience with this novel catheter in a variety of cardiac arrhythmias and to compare the mapping performance with the 5-spline Pentaray. METHODS: Fifty consecutive procedures among 46 patients were retrospectively analyzed regarding safety, efficacy, and acute procedural success defined as termination or noninducibility of clinical tachycardia, conduction block across an ablation line, or pulmonary vein isolation. In addition, another 10 patients with sustained atrial tachycardia mapped with the 5-spline catheter (2-5-2 spacing) or the novel 8-spline catheter (2-2-2-2-2 spacing) were analyzed. RESULTS: Left atrial and ventricular mapping by either transseptal (n = 41) or retroaortic (n = 2) access was feasible without any complications related to the multispline design of the novel catheter. The acute procedural success rate was 94%. In sustained atrial tachycardia compared with the 5-spline catheter, the novel 8-spline catheter recorded more electrograms per map (3,628 ± 714 vs 11,350 ± 1,203; P < 0.001) in a shorter mapping time (13 ± 2 vs 9 ± 1 minutes; P = 0.08) resulting in a higher point density (18 ± 4 vs 59 ± 10 electrograms/cm2; P < 0.01) and point acquisition rate (308 ± 69 vs 1,332 ± 208 electrograms/min.; P < 0.01). CONCLUSIONS: In this initial experience, mapping with the novel catheter was safe and efficient with a high electroanatomical resolution. In sustained atrial tachycardia the novel 8-spline catheter demonstrated a marked increase in point density and mapping speed compared with those of the 5-spline catheter. These initial results should be validated in a larger multicenter cohort with longer follow-up.

Device interaction between cardiac contractility modulation (CCM) and subcutaneous defibrillator (S-ICD).

Combined implantation of cardiac contractility modulation (CCM) with subcutaneous implantable cardioverter-defibrillator (S-ICD) appears a suitable option to reduce the amount of intracardiac leads and complications for patients. Here we report on a patient with ischemic cardiomyopathy carrying an S-ICD in which a CCM device was implanted. During crosstalk testing post-CCM implantation, the S-ICD misannotated QRS complexes and T waves. The problem was solved through reprogramming the CCM, while preserving S-ICD functionality and improving heart failure symptoms. In conclusion, S-ICD combined with CCM seems to be a good and safe option for patients when device interference is being ruled out.