Influence of ablation index on the incidence of cardiac tamponade complicating pulmonary vein isolation.

BACKGROUND: Cardiac tamponade (CT) complicating pulmonary vein isolation (PVI) for atrial fibrillation (AF) is a complication that can increase morbidity and mortality. Radiofrequency energy is a known cause of CT. Ablation Index (AI) is a novel ablation quality marker. We hypothesized that use of AI reduces the incidence of CT. METHODS: All AF procedures between 10/2014 and 06/2019 were included. Three ablation groups were defined: group A, RF ablation with non-contact force (CF) catheter; group B, RF ablation with CF catheter; and group C, RF ablation with CF catheter using AI. All episodes of CT were analyzed. RESULTS: In total, 1222 consecutive AF patients underwent PVI. Group A consisted of 100 (8%) procedures, while group B included 432 (35%) procedures and group C 690 (57%) procedures. The overall risk for CT in all patients was 2.1% (26/1222). The risk in group A was 2.9% (3/100), in group B 2.5% (11/432), and in group C 1.7% (12/690), including all 1222 patients in the analysis (p < 0.05). Univariate analysis identified no further specific predictors for CT. With the exception of one patient (1/26; 3.8%), who needed surgical treatment, all CT could be successfully drained. CONCLUSIONS: In a high-volume center, the use of AI decreased the risk of CT in patients undergoing RF ablation for AF by 32%.

The BioMonitor 2 insertable cardiac monitor: Clinical experience with a novel implantable cardiac monitor.

INTRODUCTION: Implantable loop recorders (ILR) are leadless subcutaneous devices that allow cardiac monitoring for up to 3 years and are a valuable tool in the diagnosis of arrhythmias, cryptogenic stroke and unexplained syncope. The Biotronik BioMonitor 2 is a novel, insertable ILR allowing long-term continuous monitoring with wireless telemetry options. METHODS: A single-center, prospective, observational study investigating the reliability of sensing quality and detection performance in the BioMonitor 2 ILR, as well as post-implantation patient satisfaction. R-wave amplitude was recorded immediately post implantation and 1 day post implantation, followed by extensive patient instruction. Follow-up was scheduled after 3 months, or after an event. Data from the ILR were retrieved, with documentation of all episodes, R-wave amplitude and noise burden. The anatomical position of the ILR was determined 1 day post implantation and after 3 months. A patient questionnaire was conducted after 3 months. RESULTS: 30 consecutive patients (mean age 71 ±â€¯12 years, 56% male) were analyzed. Indications for ILR implantation were: unexplained syncope (n = 24, 80%), suspected atrial fibrillation (n = 4, 13%), cryptogenic stroke (n = 1, 3%) and palpitations (n = 1, 3%). Median time from skin cut to suture was 8 min. No complications occurred. Mean R-wave amplitude at implantation was 0.84 ±â€¯0.32 mV, at day 1 post implantation 0.96 ±â€¯0.31 mV, and after a mean follow-up of 85 ±â€¯24 days 1.02 ±â€¯0.47 mV (p = 0.01). The mean noise burden was 1.4 ±â€¯2%. CONCLUSION: Implantation of the novel BioMonitor 2 ILR is fast and uncomplicated. Initial sensing values are good and improve over time.

One-year outcome and durability of pulmonary vein isolation after prospective use of ablation index for catheter ablation in patients with persistent atrial fibrillation.

BACKGROUND: Radiofrequency (RF) catheter ablation for persistent atrial fibrillation (peAF) is associated with less favorable outcomes than for paroxysmal AF (PAF). Recent studies have shown improved clinical outcomes with use of ablation index (AI) targets for pulmonary vein isolation (PVI) in PAF. AI is a novel ablation quality marker that incorporates contact force (CF), time, and power in a weighted formula. This is a single-arm registry to investigate the 1-year efficacy of AF ablation guided by the AI in patients with peAF, and further to evaluate pulmonary vein reconduction at repeat electrophysiology study in case of recurrent AF. METHODS: In total, 55 consecutive patients (69 ± 10 years, 55% male, median time since first AF diagnosis: 31 months (Q1-Q3: 10-70)) with peAF underwent AIguided PVI using a CF surround-flow catheter. AI targets were 600 for anterior and 450 for roof/posterior/inferior antral segments. Patients were monitored for atrial tachyarrhythmia recurrence using 5-day Holter-ECG recordings at 3, 6, and 12 months. RESULTS: The median procedure time was 173 min (Q1-Q3: 152-204). The median fluoroscopy time was 4 min (Q1-Q3: 3-6) and the median fluoroscopy dose was 2.64 Gy/cm2 (Q1-Q3: 1.04-3.99). The median ablation time was 57 min (Q1-Q3: 47-63). At 12 months, 42% of the patients were in sinus rhythm. AF recurrence was seen in 58% of patients. No major complications occurred. CONCLUSIONS: RF ablation using AI in peAF is a feasible and safe technique. At 1 year, AI-guided ablation was associated with AF recurrence in 58% of the patients.

Impact of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers on the long-term outcome after pulmonary vein isolation for paroxysmal atrial fibrillation.

OBJECTIVES: The effect of angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARBs) on the long-term outcome after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (PAF) is unknown. METHODS: This matched-pair study included 102 patients with PAF treated with ACE-I or ARBs (group 1) and 102 control subjects (group 2) after standardized PVI. Tele-ECG recorders were used to detect the end point of the first PAF recurrence after a 3-month blanking period. RESULTS: Median follow-up was 2.1 years (range 0.3-6.3). In group 1, 51 (50%) patients suffered recurrences, with a mean time to recurrence of 3.2 years (95% CI 2.6-3.8). In group 2, 67 (65.7%) patients presented PAF after a mean period of 2.2 years (95% CI 1.7-2.8; p = 0.009). A second ablation was performed in 31 (50%) patients from the treatment group and in 48 (66.7%) patients from the control group (p = 0.02). Multivariate Cox analysis showed treatment with ACE-I and ARBs to be the only significant predictor of a reduced recurrence rate (HR 0.49, 95% CI 0.32-0.75). CONCLUSION: ACE-I and ARBs were effective for the preservation of sinus rhythm after PAF ablation, and they reduced the reablation rate.

Initial experience of percutaneous left atrial appendage closure using the LAmbre device for thromboembolic prevention.

AIMS: Stroke due to atrial fibrillation has been associated with a high risk of disability and mortality. Percutaneous left atrial appendage (LAA) closure has been established as an alternative strategy for stroke prevention in patients not eligible for oral anticoagulation. The LAmbre is a novel occluder, specifically designed for LAA closure adaptive to various LAA anatomies. The aim of this study was to demonstrate feasibility and initial experience in a nonprescreened patient cohort for LAA occlusion using the novel LAmbre occluder. METHODS: The device was implanted in 11 patients with nonvalvular atrial fibrillation. Follow-up included transesophageal echocardiography and an outpatient visit at 6 weeks and 6 months after implantation. RESULTS: All devices were implanted successfully. Device sizes ranged from 16/22 to 22/34 mm. Patients' mean CHA2DS2-VASc and HAS-BLED scores were 3.3 ±â€Š1.0 and 3.2 ±â€Š1.0, respectively. Two out of 11 patients had previously been rejected for Watchman occluder implantation by reasons of too small LAA. At 6 weeks and 6 months, there were no deaths, strokes, systemic thromboembolism or severe bleeding complications. There was no device-related thrombus or pericardial effusion seen with transesophageal echocardiography. In one out of 11 patients, a minimal peridevice flow (less than 5 mm) was present at 6-week follow-up. CONCLUSION: The LAmbre occluder is a novel LAA-closure device with features that provide many options for LAA-closure to physicians, particularly in patients with challenging anatomies. From our initial experience, implantation is associated with a good success rate and clinical outcome.

Introduction of an expert system for the discrimination of local pulmonary vein and atrial far field signals.

BACKGROUND: Discrimination of local and far field potentials during sinus rhythm and atrial fibrillation (AF) is essential for successful pulmonary vein (PV) isolation. We sought to introduce an expert system for the classification of electrophysiologic PV signals. METHODS: For the expert system database, we analyzed ablation procedures of 50 patients with paroxysmal and persistent AF. Standard circumferential catheters and bipolar recordings were required. In a prospective trial, the expert system was compared with the performing electrophysiologists' classifications of potentials during 15 procedures. A total of 1,343 recordings of local PV and far field signals were validated by the sudden disappearance of local potentials during ablation, the presence of dissociated PV activity, and pacing maneuvers. A fast Fourier transform was applied to the individual potentials. Analysis continued in the amplitude and phase representation. RESULTS: Four parameters significant (p < 0.001) for classification were identified and entered a logistic regression model. Overall sensitivity and specificity of the model was 87% with minor, nonsignificant variations for individual PVs and different underlying rhythms. Concordance with ad hoc electrophysiologists' classification of local potentials was 70%, which increased during post hoc analysis to 86% since classification of 14% of the potentials had to be revised. For these potentials, the expert system correctly predicted their local origin in 86%. CONCLUSION: An expert system for the evaluation of electrophysiologic signals based on morphology analysis using the Fourier transform is feasible. The ease of use and online availability facilitate a widespread use for AF ablation procedures.