Dielectric-based tissue thickness measured during radiofrequency catheter ablation.

INTRODUCTION: A new dielectric-based method (KODEX-EPD mapping system, EPD Solutions, a Philips company) for measuring tissue thickness at the catheter-tissue interface has recently been developed. We reported preliminarydata on real-time catheter-based measuring myocardial wall thickness in vivo, during typical atrial flutter radio frequency ablation. METHODS AND RESULTS: The study population consisted of 12 consecutive patients, suffering from symptomatic paroxysmal or persistent cavo-tricuspid isthmus dependent, counter clockwise and clockwise AFL, under going a first catheter ablation between April 2021 and November 2021. The new KODEX-EPD function, Wall Viever, was used to calculate atrialwall thickness. The atrial wall thickness was significantly higher closeto the tricuspid annulus than close to the inferior vena cava (3.6 ± 0.5 mm vs 2.4 ± 0.3 mm, p < .001) and a trend towards a progressive decrease of atrial wall thickness was observed moving the mapping catheter from the tricuspidvalve to the inferior vena cava. CONCLUSIONS: Thenew KODEX-EPD function, Wall Viever, allowed us to assess atrial wall thickness during atrial flutter radio frequency ablation.

Fluoroscopy and contrast media use in cryoballoon ablation of atrial fibrillation using a novel imaging system.

Pulmonary vein (PV) isolation using cryoballoon (CB) catheter is generally characterized by a high radiation and contrast media exposure. A new dielectric imaging system (KODEX-EPD imaging system) allows pulmonary vein (PV) occlusion assessment without dye use. The purpose of this study was to verify the feasibility of reducing the radiation and dye use during CB ablation in patients with atrial fibrillation (AF) using the new dielectric imaging system. In a retrospective, single center study, we enrolled 34 consecutive patients with paroxysmal AF divided in two groups: 17 patients in Conventional Group underwent the procedure under fluoroscopy guidance before the new system introduction, while 17 patient in KODEX-EPD Group underwent the procedure under fluoroscopy and KODEX-EPD imaging system guidance. There were no differences in any clinical and anatomical characteristics between the two study groups. Overall procedure time was comparable between the two groups (69 [IQR 63-98] min in Conventional Group vs. 65 [IQR 58-74] min in KODEX-EPD Group, p = 0.16), while fluoroscopy time (8 [IQR 5-9] min vs. 11 [IQR 9-12] min, p = 0.014) and dye use (35 [IQR 28-45] ml vs. 70 [IQR 57-83] ml, p < 0.001) were significantly lower in the KODEX-EPD Group. No 30-day complications were observed. At 12-month follow-up 7/37 (19%) patients had an atrial arrhythmias recurrence, without any difference between the two study groups (17.6% vs. 23.5%, p = 0.68). The use of a new dielectric imaging system allowed a significantly reduction in radiation exposure and dye use during CB ablation in patients with AF.

Electrical Substrate Elimination in 135 Consecutive Patients With Brugada Syndrome.

BACKGROUND: There is emerging evidence that localization and elimination of abnormal electric activity in the epicardial right ventricular outflow tract may be beneficial in patients with Brugada syndrome. METHODS AND RESULTS: A total of 135 symptomatic Brugada syndrome patients having implantable cardiac defibrillator were enrolled: 63 (group 1) having documented ventricular tachycardia (VT)/ventricular fibrillation (VF) and Brugada syndrome-related symptoms, and 72 (group 2) having inducible VT/VF without ECG documentation at the time of symptoms. About 27 patients of group 1 experienced multiple implantable cardiac defibrillator shocks for recurrent VT/VF episodes. Three-dimensional maps before and after ajmaline determined the arrhythmogenic electrophysiological substrate (AES) as characterized by prolonged fragmented ventricular potentials. Primary end point was identification and elimination of AES leading to ECG pattern normalization and VT/VF noninducibility. Extensive areas of AES were found in the right ventricle epicardium, which were wider in group 1 (P=0.007). AES increased after ajmaline in both groups (P<0.001) and was larger in men (P=0.008). The increase of type-1 ST-segment elevation correlated with AES expansion (r=0.682, P<0.001). Radiofrequency ablation eliminated AES leading to ECG normalization and VT/VF noninducibility in all patients. During a median follow-up of 10 months, the ECG remained normal even after ajmaline in all except 2 patients who underwent a repeated effective procedure for recurrent VF. CONCLUSIONS: In Brugada syndrome, AES is commonly located in the right ventricle epicardium and ajmaline exposes its extent and distribution, which is correlated with the degree of coved ST-elevation. AES elimination by radiofrequency ablation results in ECG normalization and VT/VF noninducibility. Substrate-based ablation is effective in potentially eliminating the arrhythmic consequences of this genetic disease. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier: NCT02641431.

Which is the best catheter to perform atrial fibrillation ablation? A comparison between standard ThermoCool, SmartTouch, and Surround Flow catheters.

INTRODUCTION: Catheter ablation (CA) is an established therapy for atrial fibrillation (AF). The SmartTouch catheter (STc) provides information about catheter tip to tissue contact force (CF). The Surround Flow catheter (SFc) provides a uniform cooling of the tip during ablation. We sought to analyze the impact of STc and SFc on CA of paroxysmal AF in terms of feasibility and acute efficacy. METHODS AND RESULTS: Sixty-three patients (mean age 57.6 ± 9.8 years, 53 males) with paroxysmal AF underwent pulmonary veins (PVs) antral isolation, by using standard ThermoCool catheter (TCc) in 21, STc in 21, and SFc in 21. Total procedural, fluoroscopy, and radiofrequency (RF) delivery times; percentage of persistently deconnected PVs after 30 min; and percentage of isolated PVs at the end of the procedure were measured. The use of both STc and SFc obtained a reduction of fluoroscopy time (TCc 34 ± 18 min, STc 20 ± 10 min, p < 0.001; SFc 21 ± 13 min, p = 0.02 vs TCc) and RF time (TCc 41 ± 13 min, STc 30 ± 14 min, p = 0.013; SFc 30 ± 9 min, p < 0.01 vs TCc). The use of STc resulted in a reduction of procedural time (TCc 181 ± 53 min, STc 140 ± 53 min, p < 0.001; SFc 170 ± 51 min, p = NS vs TCc). The percentage of isolated PVs was comparable between groups (TCc 96 % vs STc 98 % vs SFc 96 %; p = NS). The percentage of deconnected PVs at 30 min was lower in TCc (89 %) than in STc (95 %) and in SFc (95 %) group (p < 0.05). CONCLUSIONS: Both STc and SFc allowed a simplification of CA of paroxysmal AF. In addition, they reduced early PVs reconnection. Sixty-three patients with paroxysmal AF underwent ablation by standard ThermoCool, SmartTouch, or Surround Flow catheter. Both the SmartTouch and the Surround Flow significantly reduced radiofrequency and fluoroscopy times, as well as pulmonary veins reconnection rate at 30 min. Moreover, the SmartTouch reduced overall duration of the procedure.