Implantable loop recorders in patients with Brugada syndrome: the BruLoop study.

BACKGROUND AND AIMS: Available data on continuous rhythm monitoring by implantable loop recorders (ILRs) in patients with Brugada syndrome (BrS) are scarce. The aim of this multi-centre study was to evaluate the diagnostic yield and clinical implication of a continuous rhythm monitoring strategy by ILRs in a large cohort of BrS patients and to assess the precise arrhythmic cause of syncopal episodes. METHODS: A total of 370 patients with BrS and ILRs (mean age 43.5 ± 15.9, 33.8% female, 74.1% symptomatic) from 18 international centers were included. Patients were followed with continuous rhythm monitoring for a median follow-up of 3 years. RESULTS: During follow-up, an arrhythmic event was recorded in 30.7% of symptomatic patients [18.6% atrial arrhythmias (AAs), 10.2% bradyarrhythmias (BAs), and 7.3% ventricular arrhythmias (VAs)]. In patients with recurrent syncope, the aetiology was arrhythmic in 22.4% (59.3% BAs, 25.0% VAs, and 15.6% AAs). The ILR led to drug therapy initiation in 11.4%, ablation procedure in 10.9%, implantation of a pacemaker in 2.5%, and a cardioverter-defibrillator in 8%. At multivariate analysis, the presence of symptoms [hazard ratio (HR) 2.5, P = .001] and age >50 years (HR 1.7, P = .016) were independent predictors of arrhythmic events, while inducibility of ventricular fibrillation at the electrophysiological study (HR 9.0, P < .001) was a predictor of VAs. CONCLUSIONS: ILR detects arrhythmic events in nearly 30% of symptomatic BrS patients, leading to appropriate therapy in 70% of them. The most commonly detected arrhythmias are AAs and BAs, while VAs are detected only in 7% of cases. Symptom status can be used to guide ILR implantation.

Atrial fibrillation cycle-length (AF-CL) inside the pulmonary veins predicts paroxysmal AF ablation success- the INDUCE-AF study.

BACKGROUND: A novel method to measure atrial fibrillation cycle length (AF-CL) was recently described, based on the average of 10 consecutive signals (FARS10). FARS10 accurately identified pulmonary vein isolation (PVI)-responders among patients with persistent AF. Whether this method is applicable to patients with paroxysmal AF is unknown. OBJECTIVE: The aim of this study is to evaluate the prognostic value of FARS10 measurements in patients with paroxysmal AF. METHODS AND RESULTS: We enrolled paroxysmal AF patients undergoing PVI in a prospective multicenter study. After AF induction with a standardized protocol, the AF-CL was measured using FARS-10 method. The primary endpoint was AF/AT-recurrence. One-hundred and four patients were included (61 ± 14 years, 25% females). After a mean follow-up of 12 ± 4 months, AF/AT recurrence rate was 20%. The fastest PV CL (fPV-CL) was independently associated with the primary endpoint at multivariate analysis (HR 1.02, p < 0.001). Every 10 ms increase in fPV-CL, AF recurrences increased by 20%. The value of 160 ms was found to be the optimal cut-off (specificity 81%, sensitivity 76%). Patients with fPV-CL < 160 ms experienced lower AF recurrences as compared to patients with fPV-CL > 160 ms (8% vs. 32% at 1 year; HR = 0.17, p < 0.001). Progression to persistent AF was observed in 13% of patients with fPV-CL > 160 ms. CONCLUSION: fPV-CL measured with the FARS-10 method accurately predicts PVI success in paroxysmal AF patients undergoing PVI. Patients with slow PV activity (fPV-CL > 160 ms) experience higher AF recurrence rate after PVI and more frequent progression to persistent AF. In 104 patients with paroxysmal atrial fibrillation (AF) undergoing AF ablation, AF was induced at the beginning of the procedure. Pulmonary vein activity was measured using FARS10 measurement (10 consecutive fastest atrial repetitive similar morphology signals). The value of 160 ms was found to be the best cut-off to discriminate outcomes. At 1-year follow-up, patients with fast veins (< 160 ms) experienced significantly fewer AF recurrences as compared to patients with slow veins (> 160 ms). PV activity measured with FARS10 method accurately discriminates pulmonary vein isolation responders, in patients with paroxysmal AF. ABBREVIATIONS: AF atrial fibrillation, AT atrial tachycardia, CL cycle length, FARS10: 10 consecutive fastest atrial repetitive similar morphology signal, fPV fastest pulmonary vein, HR hazard ratio, ms milliseconds.

Dynamic changes of left atrial substrate over time following pulmonary vein isolation: the Progress-AF study.

AIMS: Little is known about dynamic changes of the left atrial (LA) substrate over time in patients with atrial fibrillation (AF). This study aims to evaluate substrate changes following pulmonary vein isolation (PVI). METHODS AND RESULTS: In our prospective observational study, consecutive patients undergoing first PVI-only and redo ablation were included. High-density maps of the two procedures were compared. Progression or regression was diagnosed if a significant concordant decrease or increase in bipolar voltages in ≥2 segments was observed, respectively. In 28 patients (61.2 ± 9.5 years, 39% female, 53.5% persistent AF), 111.013 voltage points from 56 high-density LA maps (1.982 points/patient) were analysed. Comparing the high-density maps of the first and second procedures, in the progression group (17 patients, 61%), there was a decrease in global (-35%, P < 0.001) and all regional voltages. In the regression group (11 patients, 39%), there was an increase in global (+43%, P < 0.001) and regional voltages. Comparing the progression with the regression group, the area of low-voltage zone (LVZ) increased (+3.5 vs. -4.5 cm2, P < 0.001) and LA activation time prolonged (+8.0 vs. -9.1 ms, P = 0.005). Baseline clinical parameters did not predict progression or regression. In patients with substrate progression, pulmonary veins (PVs) were more frequently isolated (P = 0.02) and the AF pattern at recurrence was more frequently persistent (P = 0.005). CONCLUSION: Our study describes bidirectional dynamic properties of the LA substrate with concordant either progressive or regressive changes. Regression occurs with reduced AF burden after the first procedure, while progression is associated with persistent AF recurrence despite durable PV isolation. The dynamic nature of LA substrate poses questions about LVZ-based ablation strategies.

Gender-Related Differences in Atrial Substrate in Patients with Atrial Fibrillation.

Gender-related differences have been reported in patients who underwent pulmonary vein isolation (PVI). Atrial substrate plays a role in the outcomes after ablation but gender-related differences in atrial substrate have never been described in detail. We sought to analyze gender-related differences in atrial remodeling (spontaneous low-voltage zones [LVZs]) and their clinical relevance after PVI. We conducted a prospective multicenter study, including consecutive patients who underwent first PVI-only atrial fibrillation (AF) ablation. LVZs were analyzed on high-density electroanatomical maps collected with multipolar catheter, before PVI. In total, 262 patients (61 ± 11 years, 31% female, 50% persistent AF) were followed for 28 months. In women, LVZs were larger (10% vs 4% of left atrial surface [p <0.001]) and female gender was independently associated with fourfold higher risk of having advanced (LVZ > 15%) atrial remodeling (odds ratio 4.56, p <0.001). AF recurrence-free survival was not different between men and women (log-rank p = 0.2). Although LVZs were independently associated higher AF recurrences at multivariate analysis (hazard ratio [HR] 1.2, p = 0.038), female gender was not (HR 1.4, p = 0.211). Specifically, the LVZ cutoff to predict outcomes was different in men and women: >5% in men (HR 3.0, p <0.001), >15% in women (HR 2.7, p = 0.02). In conclusion, women have more widespread LVZ in all left atrial regions. Despite more extensive atrial remodeling, the AF recurrence rate is similar in men and women, and LVZs become prognostic in women only at high burden (>15%). LVZs seem to have a different prognostic role in men and women.

Left Bundle Branch Area Defibrillator (LBBAD): A First-in-Human Feasibility Study.

BACKGROUND: Left bundle branch area (LBBA) pacing is a promising pacing technique. LBBA implantable cardioverter-defibrillator (ICD) lead implantation reduces the number of leads in patients with both pacing and ICD indications, reducing cost and potentially increasing safety. LBBA positioning of ICD leads has not previously been described. OBJECTIVES: The goal of this study was to evaluate the safety and feasibility of implanting an LBBA ICD lead. METHODS: This prospective, single-center, feasibility study was conducted in patients with an ICD indication. LBBA ICD lead implantation was attempted. Acute pacing parameters and paced electrocardiography data were collected, and defibrillation testing was performed. RESULTS: LBBA defibrillator (LBBAD) implantation was attempted in 5 patients (mean age 57 ± 16.5 years; 20% female) and achieved in 3 (60%). Mean procedural and fluoroscopy duration were 170.0 ± 17.3 minutes and 28.8 ± 16.1 minutes, respectively. Left bundle capture was achieved in 2 patients (66%) and left septal capture in 1 patient. LBBA pacing exhibited a mean QRS duration and V6 R-wave peak time of 121.3 ± 8.3 milliseconds and 86.1 ± 10.0 milliseconds. In all 3 patients, defibrillation testing was successful with mean time to adequate shock delivery of 8.6 ± 2.6 seconds. Acute LBBA pacing threshold and R-wave amplitudes were 0.80 ± 0.60 V at 0.4 milliseconds and 7.0 ± 2.7 mV. No LBBA lead-related complications occurred. CONCLUSIONS: This first-in-human evaluation showed the feasibility of LBBAD implantation in a small cohort of patients. With current tools, implantation remains complex and time-consuming. Considering the feasibility reported and the potential benefits, further technological development in this field is warranted with evaluation of long-term safety and performance.

Right Coronary Artery Chronic Total Occlusion After Bypass Grafting Successfully Treated Using Reverse Controlled Antegrade and Retrograde Subintimal Tracking (CART) Technique via the Gastroepiploic Artery: A Case Report.

BACKGROUND Percutaneous coronary intervention (PCI) of chronic total occlusions (CTO) is a well-established treatment option, improving health status and angina in selected patients with angina and/or a large area of documented ischemia and suitable anatomy. It has been used in patients with a history of coronary artery bypass grafting (CABG) but remains controversial in unusual bypass constructions. This report is of a 63-year-old man with angina due to right coronary CTO, 6 years following CABG, successfully treated using the reverse controlled antegrade and retrograde subintimal tracking technique (reverse CART technique) via the gastroepiploic (GE) artery. CASE REPORT A 63-year-old man with a history of extensive coronary artery disease, including a CTO of the right coronary artery (RCA), previously treated with a right GE artery bypass graft, presented with unacceptable angina despite optimal medical treatment. A vascular CT scan suggested severe stenosis at the level of the anastomosis between the GE artery graft and the posterior descending (PD) artery. A PCI of the native RCA CTO was successfully performed using the GE artery bypass graft as a retrograde conduit, with good angiographical and clinical outcomes. CONCLUSIONS PCI of a CTO via the GE artery has been described only occasionally before, and remains a rare treatment. This report shows that retrograde coronary artery recanalization of CTO using the reverse CART technique, via the GE artery bypass graft, was safe and effective in this case, and that it can and should be considered in selected patients.