Pre-procedural imaging with cardiac computed tomography for endo-epicardial ventricular tachycardia ablation.

BACKGROUND: Studies evaluating the systematic use of cardiac computer tomography (CCT) for the pre-procedural assessment of myocardial fibrosis are limited and their implementation in the electrophysiology workflow has not been extensively described. OBJECTIVE: To explore the degree of concordance between cardiac fibrosis evaluated by CCT compared to electroanatomical mapping (EAM) in patients undergoing endo-epicardial ventricular tachycardia (VT) ablation. METHODS: From November-2017 to December-2021, patients undergoing endo-epicardial VT catheter ablation (CA) with CCT as the only source of pre-procedural scar assessment were prospectively enrolled. After image integration, myocardial fibrosis detected with CCT was compared with low voltage areas identified by endo-epicardial EAM. Post-procedural VT recurrences of this approach were evaluated after at least one-year follow-up. RESULTS: 35 patients (mean age 60.7±13.2 years, 94.2% males) were enrolled. The most common underlying arrhythmic substrate was dilated cardiomyopathy (48.6%). CCT was employed for contraindications to cardiac magnetic resonance, as unstable VTs (31.4%) or non-conditional ICDs (28.8%), but also for patients' and operators' preferences (14.3%-25.7%). Myocardial fibrosis was correctly identified by CCT and EAM, with strong agreement between these two techniques, both overall (Cohen's Kappa for agreement=0.933) and in per-segment analysis (K ranging from 0.796 to 1.0). Ischemic patients showed the best correlation (K=1.000) while myocarditis showed the worst (K=0.750). After a median follow-up of 14 [12-24] months, 1-year freedom from recurrences was achieved in 74.3% patients; overall freedom from recurrences was 60.0%. CONCLUSIONS: A CCT-based pre-procedural assessment pre-VT ablation is feasible, showing high diagnostic concordance with EAM in detecting myocardial fibrosis.

Atrioventricular nodal reentry tachycardia treatment using CARTO 3 V7 activation mapping: a new era of slow pathway radiofrequency ablation is under coming.

Background: Slow pathway (SP) ablation is the cornerstone for atrioventricular nodal reentry tachycardia (AVNRT) treatment, and a low-voltage bridge offers a good target during mapping using low x-ray exposure. We aimed to assess a new tool to identify SP by activation mapping using the last CARTO3® version, i.e., CARTO PRIME® V7 (Biosense Webster, Diamond Bar, CA, USA). Methods and results: Right atrial septum and triangle of Koch 3D-activation map were obtained from intracardiac contact mapping during low x-ray CARTO 3® procedure. In 60 patients (mean age 60.3 ± 14.7, 61% females) undergoing ablation for AVNRT, an automatic activation map using a DECANAV® mapping catheter and CARTO® Confidense™, Coherent, and FAM DX software modules were obtained. The SP was identified in all patients as the latest atrioventricular node activation area; RF catheter ablation (RFCA) in that region elicited junctional beats. The mean procedural time was 150.3 ± 48.3 min, the mean fluoroscopy time exposure was 2.9 ± 2 min, the mean dose-area product (DAP) was 16.5 ± 2.7 cGy/cm2. The mean number of RF applications was 3.9 ± 2, the mean ablation index was 428.6 ± 96.6, and the mean contact force was 8 ± 2.8 g. There were no adverse event during the procedure, and no AVNRT recurrences occurred during a mean follow-up of 14.3 ± 8.3 months. Conclusion: Ablation of the SP by automatic mapping using Confidense™, Coherent, and FAM DX software modules is an innovative, safe, and effective approach to AVNRT ablation. The CARTO3® V7 system shows on a 3D map the latest AV node activation area during sinus rhythm allowing low fluoroscopy time and highly effective RFCA.

Live integration of comprehensive cardiac CT with electroanatomical mapping in patients with refractory ventricular tachycardia.

BACKGROUND: Aim of the present study was to verify the feasibility and accuracy of live integration of myocardial fibrosis evaluated at CCT with EAM (electro-anatomical mapping). METHODS: We prospectively enrolled a consecutive cohort of patients with clinical indication to EAM before radiofrequency catheter ablation (RFCA) of refractory ventricular tachycardia (VT) and an absolute contraindication to cardiac magnetic resonance. All patients underwent per protocol CCT for myocardial fibrosis and coronary anatomy evaluation. Diagnostic performance was assessed for myocardial fibrosis evaluation with CCT vs EAM. Live integration feasibility of CCT vs EAM was evaluated for every patients. RESULTS: A total of 19 patients were included in the present study with 323 myocardial segments analyzed for myocardial fibrosis at CCT. In all patients CCT data were successfully integrated with EAM during RFCA procedure. All patients had myocardial fibrosis correctly identified at CCT vs EAM on a per-patients basis. A diagnostic accuracy on a per-segment basis of 94.1% for detection of any type of myocardial fibrosis at CCT vs EAM was recorded. CONCLUSIONS: CCT identification of myocardial fibrosis is feasible and accurate vs EAM in a very selected high risk patients with clinical indication to RFCA of VT and contraindication to CMR.

Comparison between First- and Second-Generation Cryoballoon for Paroxysmal Atrial Fibrillation Ablation.

Introduction. Cryoballoon (CB) ablation has emerged as a novel treatment for pulmonary vein isolation (PVI) for patients with paroxysmal atrial fibrillation (PAF). The second-generation Arctic Front Advance (ADV) was redesigned with technical modifications aiming at procedural and outcome improvements. We aimed to compare the efficacy of the two different technologies over a long-term follow-up. Methods. A total of 120 patients with PAF were enrolled. Sixty patients underwent PVI using the first-generation CB and 60 patients with the ADV catheter. All patients were evaluated over a follow-up period of 2 years. Results. There were no significant differences between the two groups of patients. Procedures performed with the first-generation CB showed longer fluoroscopy time (36.3 ± 16.8 versus 14.2 ± 13.5 min, resp.; p = 0.00016) and longer procedure times as well (153.1 ± 32 versus 102 ± 24.8 min, resp.; p = 0.019). The overall long-term success was significantly different between the two groups (68.3 versus 86.7%, resp.; p = 0.017). No differences were found in the lesion areas of left and right PV between the two groups (resp., p = 0.61 and 0.57). There were no significant differences in procedural-related complications. Conclusion. The ADV catheter compared to the first-generation balloon allows obtaining a significantly higher success rate after a single PVI procedure during the long-term follow-up. Fluoroscopy and procedural times were significantly shortened using the ADV catheter.

Manifold benefits of choosing a minimally fluoroscopic catheter ablation approach.

We report the case of a 14-year-old boy with ventricular preexcitation. A standard, fluoroscopy guided, ablation procedure was successfully performed in a postero-midseptal region with a total fluoroscopy time of about 45 min (2430 cGy.cm(2)). A few hours after the procedure, preexcitation reappeared. A second ablation procedure was scheduled using the EnSite NavX™ mapping system. During mapping along the tricuspid groove, preexcitation suddenly disappeared due to mechanical "bumping" of the accessory pathway and it did not recover over the next 30 min. As per our routine practice, the phase of geometry reconstruction has been continuously recorded by the system; thus, an off-line analysis allowed to pinpoint the site of earliest activation and the site of mechanical bumping, where radiofrequency obtained the accessory pathway ablation. The second procedure was performed without using fluoroscopy at all. Thanks to the geometry reconstruction, the procedure was completely successful thus avoiding a further rehospitalization.