ABSTRACT
BACKGROUND: Criteria such as electrograms voltage or late potentials have been largely utilized in the past to help identify areas of substrate maps that are within the ventricular tachycardia (VT) isthmus; yet their specificity and positive predictive value are quite low. The Lumipoint fractionation tool of the Rhythmia system illuminates regions with fractionated electrograms irrespective of their timing and annotation. We aimed to ascertain whether the use of this tool can rapidly identify areas within VT isthmuses from substrate maps. METHODS: Thirty patients with structural cardiomyopathy in whom a complete right ventricular-paced substrate map and a full reconstruction of the diastolic isthmus during VT could be obtained were enrolled. The VT isthmus border was projected on each substrate map to verify whether the areas illuminated by Lumipoint fell within those borders. The behavior of the electrograms detected at the illuminated areas of the substrate maps was studied during a right ventricular drive train and extra stimulus protocol: if the near field potentials showed a delayed conduction after a single extra stimulus, defined as a minimum of 10 ms increase of the time interval between the far field and the near field activation measured during the drive train, the electrogram was said to have a "decremental" behavior. RESULTS: The logistic analysis showed that areas with fractionated electrograms illuminated by the Lumipoint software and showing the greatest decremental behavior fell within the VT isthmus borders (OR = 1.66, CI: 1.41-1.75, p<0.001; OR=1.57 CI: 1.32-1.72, p<0.001, respectively) with a sensitivity, specificity, and positive predictive value of 87%, 96%, and 97%, respectively. CONCLUSIONS: Fractionated electrograms illuminated by the automated Lumipoint software on right ventricular-paced substrate maps showing the greatest decremental behavior fall within the VT isthmus borders with a probability of 0.97, irrespective of their timing, annotation, or voltage, without any need for subjective assessment of their involvement in slow conduction areas.
ABSTRACT
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, and is associated with a fivefold increase in the risk of ischemic stroke and systemic embolism. Left atrial appendage (LAA) is the source of thrombi in up to 90% of patients with nonvalvular atrial fibrillation (AF). Although thromboembolic prophylaxis by means of oral anticoagulants (OAC) has been shown to be very effective (OAC), they also confer an inevitably risk of serious bleeding. Catheter ablation (CA) is an effective treatment for symptomatic AF but its role in stroke prevention remains unproved. Recently, LAA percutaneous occlusion has been demonstrated to be equivalent to OACs in reducing thromboembolic events. The aim of this review is to describe the rationale, feasibility, outcomes and technique of a combined procedure of AFCA and percutaneous LAAO, two percutaneous interventions that share some procedural issues and technical requirements, in patients with symptomatic drug-refractory AF, high risk of stroke, and contraindications to OACs.
ABSTRACT
AIM: Current guidelines recommend atrioventricular junction (AVJ) ablation in patients with atrial fibrillation (AF) treated with cardiac resynchronization therapy (CRT). Our study compared the CRT response of patients in sinus rhythm (SR) vs. AF. METHODS AND RESULTS: In this observational, prospective, multicentre study, patients were grouped by intrinsic rhythm. For the first 2 months, the negative chronotropic drug was optimized in the AF group. If ventricular pacing was ≤85%, AVJ ablation was recommended. Responders were defined as patients who survived without requiring heart transplant and had a ≥ 10% reduction in left ventricular end-systolic volume (LVESV) at 12 months after implantation. Of 202 patients included, 156 (77%) were in SR and 46 (23%) had AF. After drug optimization, only 13/46 (28%) of the AF patients required AVJ ablation (AF + AVJ). The percentage of responders was 83/156 (53%) for SR vs. 22/46 (48%) AF (P = 0.4). Among AF patients the response was 16/33 (48%) for AF with non-AVJ ablation vs. 6/13 (46%) AF + AVJ, P = 0.56. The LVESV decreased in all three groups: -30 ± 39 mL, -24 ± 43 mL, and -22 ± 36 mL, respectively (P = 0.75). Mortality was higher in patients with AF compared with SR: 10/46 (21%) vs. 9/156 (5.7%), log rank 10.6, P <0.05. CONCLUSION: Although only 28% of the patients in AF had the AVJ ablated, there were no differences in the percentage of response and echo improvement between patients in SR and AF. However, mortality was higher in patients with AF compared with patients in SR.
