Assessment of pericardial adhesions by means of the EpiCO2 technique: Brighton Adhesion Classification.

BACKGROUND: Epicardial ablation complications are more frequent in patients with preexisting pericardial adhesions. As opposed to the dry puncture technique, the coronary vein exit and carbon dioxide (CO2) insufflation (EpiCO2) technique allows diagnosing pericardial adhesions before subxiphoid puncture. OBJECTIVE: This study aimed to evaluate the efficacy of the EpiCO2 technique in diagnosing pericardial adhesions prior to subxiphoid puncture. METHODS: Following coronary vein exit, contrast was injected in the pericardial space, and adhesions classified using our novel Brighton Adhesion Classification (BAC) into BAC-0 (no adhesions), BAC-1 (dispersed adhesions), and BAC-2 (dense adhesions extending to the entire assessed area). CO2 insufflation allowed subclassification of BAC-1 adhesions into BAC-1a (not preventing epicardial access or restricting catheter movement) and BAC-1b (either preventing epicardial access or significantly limiting catheter movement). RESULTS: Intentional coronary vein exit (right atrial appendage exit in 1 case) was achieved in all 235 consecutive epicardial ablation procedures undertaken at our center. A diagnosis of BAC-0 was made in 219 cases (93.2%), BAC-1a in 9 cases (3.8%), BAC-1b in 2 cases (0.9%), and BAC-2 in 5 cases (2.1%). This led to not attempting subxiphoid puncture in 6 cases (2.6%) and abandoning epicardial mapping because of limited catheter movement in 1 case (0.4%). Access-related complications occurred in 7 cases (3%) only in the BAC-0 group. CONCLUSION: The EpiCO2 technique allows assessment of the presence of pericardial adhesions prior to attempting subxiphoid puncture for epicardial access, which may lead to a reduction in the procedural complications within this subset of patients.

Real-world assessment of multipolar and point-by-point mapping for premature ventricular contraction ablation.

AIMS: We aimed to assess the acute and midterm efficacy of premature ventricular contraction (PVC) ablation guided by multielectrode and point-by-point (PbP) mapping. METHODS AND RESULTS: This is a retrospective, international multicentre study of consecutive patients referred for PVC ablation in 10 hospital centres from January 2017 to December 2021. Based on the mapping approach, two cohorts were identified: the 'Multipolar group', where a dedicated high-density mapping catheter was employed, and the 'PbP group', where mapping was performed with the ablation catheter. Procedural endpoints, safety, and acute (procedural) and midterm efficacies were assessed. Of the 698 patients included in this study, 592 received activation mapping [46% males, median age of 55 (41-65) years]-248 patients in the Multipolar group and 344 patients in the PbP group. A higher number of activation points [432 (217-843) vs. 95 (42-185), P < 0.001], reduced mapping time (40 ± 38 vs. 61 ± 50 min, P < 0.001), and shorter procedure time (124 ± 60 vs. 143 ± 63 min, P < 0.001) were reported in the Multipolar group. Both groups had high acute success rates (84.7% with Multipolar mapping vs. 81.3% with PbP mapping, P = 0.63), as well as midterm efficacy (83.4% vs. 77.4%, P = 0.08), with no significant differences in the risk of adverse events (6.0% vs. 3.5%, P = 0.24). However, for left-sided PVC ablation specifically, there was a higher midterm efficacy in the Multipolar group (80.7% vs. 69.5%, P = 0.04), with multipolar mapping being an independent predictor of success [adjusted OR = 2.231 (95% CI, 1.476-5.108), P = 0.02]. CONCLUSION: The acute and midterm efficacies of PVC ablation are high with both multipolar and PbP mapping, although the former allows for quicker procedures and may potentially improve the outcomes of left-sided PVC ablation.

Late Gadolinium Enhancement Cardiovascular Magnetic Resonance Assessment of Substrate for Ventricular Tachycardia With Hemodynamic Compromise.

Background: The majority of data regarding tissue substrate for post myocardial infarction (MI) VT has been collected during hemodynamically tolerated VT, which may be distinct from the substrate responsible for VT with hemodynamic compromise (VT-HC). This study aimed to characterize tissue at diastolic locations of VT-HC in a porcine model. Methods: Late Gadolinium Enhancement (LGE) cardiovascular magnetic resonance (CMR) imaging was performed in eight pigs with healed antero-septal infarcts. Seven pigs underwent electrophysiology study with venous arterial-extra corporeal membrane oxygenation (VA-ECMO) support. Tissue thickness, scar and heterogeneous tissue (HT) transmurality were calculated at the location of the diastolic electrograms of mapped VT-HC. Results: Diastolic locations had median scar transmurality of 33.1% and a median HT transmurality 7.6%. Diastolic activation was found within areas of non-transmural scar in 80.1% of cases. Tissue activated during the diastolic component of VT circuits was thinner than healthy tissue (median thickness: 5.5 mm vs. 8.2 mm healthy tissue, p < 0.0001) and closer to HT (median distance diastolic tissue: 2.8 mm vs. 11.4 mm healthy tissue, p < 0.0001). Non-scarred regions with diastolic activation were closer to steep gradients in thickness than non-scarred locations with normal EGMs (diastolic locations distance = 1.19 mm vs. 9.67 mm for non-diastolic locations, p < 0.0001). Sites activated late in diastole were closest to steep gradients in tissue thickness. Conclusions: Non-transmural scar, mildly decreased tissue thickness, and steep gradients in tissue thickness represent the structural characteristics of the diastolic component of reentrant circuits in VT-HC in this porcine model and could form the basis for imaging criteria to define ablation targets in future trials.

A preliminary assessment of the effects of ATI-2042 in subjects with paroxysmal atrial fibrillation using implanted pacemaker methodology.

AIMS: ATI-2042 (budiodarone) is a chemical analogue of amiodarone with a half life of 7 h. It is electrophysiologically similar to amiodarone, but may not have metabolic and interaction side effects. The sophisticated electrocardiograph logs of advanced DDDRP pacemakers were used to monitor the efficacy of ATI-2042. The aim of this study was to determine the preliminary efficacy and safety of ATI-2042 in patients with paroxsymal atrial fibrillation (PAF) and pacemakers. METHODS AND RESULTS: Six women with AF burden (AFB) between 1 and 50% underwent six sequential 2-week study periods. Patients received 200 mg bid of ATI-2042 during Period 2 (p2), 400 mg bid during p3, 600 mg bid during p4, 800 mg bid during p5, and no drug during baseline and washout (p1 and p6). Pacemaker data for the primary outcome measure AFB were downloaded during each period. Mean AFB decreased between baseline and all doses: AFB at baseline (SD) was 20.3 +/- 14.6% and mean AFB at 200 mg bid was 5.2 +/- 4.2%, at 400 mg bid 5.2 +/- 5.2%, at 600 mg bid 2.8 +/- 3.4%, and at 800 mg bid 1.5 +/- 0.5%. The mean reductions in AFB at all doses of ATI-2042 were statistically significant (P < 0.005). Atrial fibrillation burden increased in washout. Atrial fibrillation episodes tended to increase with ATI-2042, but this was offset by substantial decreases in episode duration. ATI-2042 was generally well tolerated. CONCLUSION: ATI-2042 effectively reduced AFB over all doses studied by reducing mean episode duration. A large-scale study will be required to confirm this effect.