Introduction
Ultrahigh‐density‐voltage mapping (uHDVM) is a new tool that can add new insights into the pathophysiology of atrial fibrillation (AF). The aim of this study was to evaluate the ...performance of uHDVM in predicting postablation AF recurrence (AFR).
Methods and Results
We included 98 consecutive patients undergoing pulmonary vein isolation for AF (40.8% persistent) using an uHDVM system and followed for 1 year. The left atrium (LA) mean voltage (Vm) and the Vslope (slope of the voltage histogram calculated by linear interpolation, with the relative frequency on the vertical axis and the bipolar potential on the horizontal axis) were calculated from 12 567 ± 5486 points per map.
Patients with AFR (N = 29) had lower Vm and higher Vslope as compared with patients without AFR (N = 69). Receiver operating characteristic curves identified Vm as the strongest predictor of AFR, with a higher incidence of AFR in patients with Vm 0.758 mV (57.6%) or lower than patients with Vm higher than 0.758 mV (15.4%; P < .0001). Among patients with Vm higher than 0.758 mV, patients with Vslope 0.637 or higher exhibited higher (P = .043) AFR incidence (31.3%) than patients with Vslope lower than 0.637 (10.2%). This classification showed incremental predictive value over relevant covariables. Vm values were lower and Vslope values were higher in patients that progressed from paroxysmal to persistent AF. Patients with Vslope 0.637 or higher had a 14.2% incidence of postablation atypical atrial flutter, whereas patients with Vslope lower than 0.637 did not present this outcome.
Conclusions
The risk of AFR, atrial flutter, and progression from paroxysmal to persistent AF can be detected by quantitative analysis of LA uHDVM identifying diverse patterns of atrial substrate alterations.
Abstract
Aims
Radiofrequency ablation creates irreversible cardiac damage through resistive heating and this temperature change results in a generator impedance drop. Evaluation of a novel local ...impedance (LI) technology measured exclusively at the tip of the ablation catheter found that larger LI drops were indicative of more effective lesion formation. We aimed to evaluate whether LI drop is associated with conduction block in patients with paroxysmal atrial fibrillation (AF) undergoing pulmonary vein isolation (PVI).
Methods and results
Sixty patients underwent LI-blinded de novo PVI using a point-by-point ablation workflow. Pulmonary vein rings were divided into 16 anatomical segments. After a 20-min waiting period, gaps were identified on electroanatomic maps. Median LI drop within segments with inter-lesion distance ≤6 mm was calculated offline. The diagnostic accuracy of LI drop for predicting segment block was assessed using receiver operating characteristic analysis.
For segments with inter-lesion distance ≤6 mm, acutely blocked segments had a significantly larger LI drop 19.8 (14.1–27.1) Ω compared with segments with gaps 10.6 (7.8–14.7) Ω, P < 0.001). In view of left atrial wall thickness differences, the association between LI drop and block was further evaluated for anterior/roof and posterior/inferior segments. The optimal LI cut-off value for anterior/roof segments was 16.1 Ω (positive predictive value for block: 96.3%) and for posterior/inferior segments was 12.3 Ω (positive predictive value for block: 98.1%) where inter-lesion distances were ≤6 mm.
Conclusion
The magnitude of LI drop was predictive of acute PVI segment conduction block in patients with paroxysmal AF. The thinner posterior wall required smaller LI drops for block compared with the thicker anterior wall.
A combination of circulating biomarkers associated with excessive myocardial collagen type-I cross-linking or CCL+ (i.e., decreased carboxy-terminal telopeptide of collagen type-I to matrix ...metalloproteinase-1 ratio) and with excessive myocardial collagen type-I deposition or CD+ (i.e., increased carboxy-terminal propeptide of procollagen type-I) has been described in heart failure (HF) patients and associates with poor outcomes.
The purpose of this study was to investigate whether the CCL+CD+ combination of biomarkers associates with atrial fibrillation (AF).
Biomarkers were analyzed in serum samples from 242 HF patients (study 1) and 150 patients referred for AF ablation (study 2). Patients were classified into 3 groups (CCL−CD−, CCL+CD− or CCL−CD+, and CCL+CD+) in accordance to biomarker threshold values. Left atrial electroanatomic high-density mapping was performed in 71 patients from study 2.
In study 1, 53.7% patients had AF at baseline and 19.6% developed AF (median follow-up 5.5 years). Adjusted odds and hazard ratios associated with baseline and new-onset AF, respectively, were both ≥3.3 (p ≤ 0.050) in CCL+CD+ patients compared with CCL−CD− patients, with nonsignificant changes in the other group. In study 2, 29.3% patients had AF recurrence during 1-year post-ablation. The adjusted hazard ratio for AF recurrence was 3.4 (p = 0.008) in CCL+CD+ patients compared with CCL−CD− patients, with nonsignificant changes in the other group. The CCL+CD+ combination added incremental predictive value over relevant covariables. CCL+CD+ patients exhibited lower left atrial voltage than the remaining patients (p = 0.005).
A combination of circulating biomarkers reflecting excessive myocardial collagen type-I cross-linking and deposition is associated with higher AF prevalence, incidence, and recurrence after ablation.
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Left atrial appendage (LAA) is the source of thrombi in up to 90% of patients with non-valvular atrial fibrillation (AF). Catheter ablation (CA) is an effective treatment for symptomatic AF and, in ...selected cases, LAA occlusion devices have been introduced as an alternative to oral anticoagulants (OACs). The safety and feasibility of combining CA and percutaneous LAA closure (LAAC) are unknown.
Patients with symptomatic drug-refractory AF, CHADS2 score of ≥1, and CHA2DS2-VASc score ≥2 were included. Catheter ablation consisted in pulmonary vein isolation with or without roof line with radiofrequency and LAA was occluded with the Watchman or Amplatzer Cardiac Plug (ACP) devices guided by angiography and transoesophageal echocardiography. A total of 35 patients were included (71% male; 70 years). Median score was 3 on both CHA2DS2-VASc and HAS-BLED, 9% had prior stroke under OAC, and 48% had bleeding complications. Successful CA and device implantation were achieved in 97% of cases. The Watchman device was used in 29 patients and ACP in 6 patients. Periprocedural complications included three cases of cardiac tamponade. At 3 months, all patients met the criteria for successful sealing of the LAA. After a mean follow-up of 13 months (3-75), 78% of patients were free of arrhythmia recurrences and OAC was withheld in 97% of patients.
The combination of CA and percutaneous LAAC in a single procedure is technically feasible in patients with symptomatic drug-refractory AF, high risk of stroke, and contraindications to OACs, although it is associated with a significant risk of major complications.
Introduction
Low‐voltage activity beyond pulmonary veins (PVs) may contribute to the failure of ablation of atrial fibrillation (AF) in the long term. We aimed to assess the presence of gaps (PVG) ...and residual potential (residual antral potential RAP) within the antral scar by means of an ultra‐high‐density mapping (UHDM) system.
Methods
We studied consecutive patients from the CHARISMA registry who were undergoing AF ablation and had complete characterization of residual PV antral activity. The Lumipoint™ (Boston Scientific) map‐analysis tool was used sequentially on each PV component. The ablation endpoint was PV isolation (PVI) and electrical quiescence in the antral region.
Results
Fifty‐eight cases of AF ablation were analyzed. A total of 86 PVGs in 34 (58.6%) patients and 44 RAPs in 34 patients (58.6%) were found. In 16 (27.6%) cases, we found at least one RAP in patients with complete absence of PV conduction. RAPs showed a lower mean voltage than PVG (0.3 ± 0.2 mV vs. 0.7 ± 0.5 mV, p < .0001), whereas the mean number of electrogram peaks was higher (8.4 ± 1.4 vs. 3.2 ± 1.5, p < .0001). The percentage of patients in whom RAPs were detected through Lumipoint™ was higher than through propagation map analysis (58.6% vs. 36.2%, p = .025). Acute procedural success was 100%, with all PVs successfully isolated and RAPs completely abolished in all study patients. During a mean follow‐up of 453 ± 133 days, 6 patients (10.3%) suffered an AF/AT recurrence.
Conclusion
Local vulnerabilities in antral lesion sets were easily discernible by means of the UHDM system in both de novo and redo patients when no PV conduction was present.
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