AVNRT cryoablation in children <26 kg: efficacy and safety of electrophysiologically guided low-voltage bridge strategy.

The recently published "electrophysiologically guided low-voltage bridge (LVB) strategy" is effective in the ablation of atrioventricular nodal re-entry tachycardia (AVNRT) in children. This study aimed to evaluate its efficacy and safety in children <26 kgs. Fourteen children [64% males, median age 6.5 years (IQR 6-8 years), median weight 25.5 kg (IQR 24-26 kg)] with AVNRT were treated. In all patients, we detected a LVB associated to a typical slow pathway potential. The acute success rate was 100% with a mean of 5.5 cryoablation deliveries. All procedures were performed with near-zero fluoroscopic exposure (median time 0.15 min, IQR 0-0.7 min), in six patients fluoroscopy was 0 min. There were no complications or recurrences during the follow-up (median 20.91 months, IQR 11.7-26.7 months).

The SIDECAR project: S-IcD registry in European paediatriC and young Adult patients with congenital heaRt defects.

AIMS: Subcutaneous-implantable cardiac defibrillators (S-ICDs) are used increasingly to prevent sudden cardiac death in young patients. This study was set up to gain insight in the indications for S-ICD, possible complications, and their predictors and follow-up results. METHODS AND RESULTS: A multicentre, observational, retrospective, non-randomized, standard-of-care registry on S-ICD outcome in young patients with congenital heart diseases (CHDs), inherited arrhythmias (IAs), idiopathic ventricular fibrillation (IVF), and cardiomyopathies (CMPs). Anthropometry was registered as well as implantation technique, mid-term device-related complications, and incidence of appropriate/inappropriate shocks (IASs). Data are reported as median (interquartile range) or mean ± standard deviation. Eighty-one patients (47% CMPs, 20% CHD, 21% IVF, and 12% IA), aged 15 (14-17) years, with body mass index (BMI) 21.8 ± 3.8 kg/m2, underwent S-ICD implantation (primary prevention in 59%). This was performed with two-incision technique in 81% and with a subcutaneous pocket in 59%. Shock and conditional zones were programmed at 250 (200-250) and 210 (180-240) b.p.m., respectively. No intraoperative complications occurred. Follow up was 19 (6-35) months: no defibrillation failure occurred, 17% of patients received appropriate shocks, 13% of patients received IAS (supraventricular tachycardias 40%, T-wave oversensing 40%, and non-cardiac oversensing 20%). Reprogramming, proper drug therapy, and surgical revision avoided further IAS. Complications requiring surgical revision occurred in 9% of patients, with higher risks in patients with three-incision procedures [hazard ratio (HR) 4.3, 95% confidence interval (95% CI) 0.5-34, P = 0.038] and BMI < 20 (HR 5.1, 95% CI 1-24, P = 0.031). CONCLUSION: This multicentre European paediatric registry showed good S-ICD efficacy and safety in young patients. Newer implantation techniques and BMI > 20 showed better outcome.

Atrial flutter catheter ablation in adult congenital heart diseases.

The important increase in life expectancy of adult patients with congenital heart disease (ACHD) has generated new challenges, including arrhythmias that represent one of the main late complications. Reentrant atrial arrhythmias are by far the main mechanism encountered, and catheter ablation has been now presented as a first-line therapy in this patient population. The number of procedures is expected to continuously increase year after year. The heterogeneity and complexity of phenotypes encountered require these cases to be performed by highly experienced operators, in specialized centers with multidisciplinary competencies. A thorough knowledge and understanding of anatomic specificities, vascular access issues, and main circuits encountered according to underlying phenotype is essential. Acute success rates have significantly improved and are now excellent, but recurrences remain a common issue, with different mechanisms or circuits frequently encountered. Observational data have suggested the interest of systematically targeting all inducible atrial arrhythmias, whether previously documented or not, and a lot of hope and research is based on the prediction of arrhythmia substrate before arrhythmia development by imaging or electroanatomic mapping to deliver a prophylactic patient tailored ablation approach. In this review, we summarize those different points in the most common or distinctive defects to offer a didactic overview of atrial flutter catheter ablation in ACHD patients.

[Ambulatory dynamic Holter monitoring: a practical guide to appropriate use and reporting in clinical cardiology]. / Elettrocardiogramma dinamico secondo Holter: dalle indicazioni alla refertazione, una guida pratica al corretto utilizzo in cardiologia clinica.

Ambulatory electrocardiographic monitoring is still a useful tool in the hands of the clinical cardiologist, for both the diagnosis of many pathologies and the management of long-term therapy. The evolution of the instrumentation, which has become sophisticated but at the same time more manageable and easy to use, has made it possible to evaluate many parameters and data. The aim of this review is to provide a general overview of this old, but not obsolete tool, to describe the main indications for its use in the light of new scientific evidence and to offer a practical guide for its appropriate use and reporting.

Zero-Fluoroscopy Ablation of Accessory Pathways in Children and Adolescents: CARTO3 Electroanatomic Mapping Combined with RF and Cryoenergy.

BACKGROUND: Fluoroscopic catheter ablation of cardiac arrhythmias in pediatric patients exposes the patients to the potential risk of radiation considering the sensitivity of this population and its longer life expectancy. We evaluated the feasibility, safety, and efficacy of accessory pathway (AP) ablation guided by CARTO3 electroanatomic mapping (EAM) system with both cryoenergy and radiofrequency (RF) energy in order to avoid x-ray exposure in pediatric patients. METHODS: We included 44 patients (mean age: 13.1 ± 3.3 years); nine of 44 presented concealed AP. An electrophysiological study with a three-dimensional EAM reconstruction was performed in every patient with a venous transfemoral direct right atrium approach or an arterial transfemoral retrograde approach to reach the mitral annulus. In two patients with left-sided AP, the ablation was performed via a patent foramen ovale. RESULTS: A total of 47 APs were present, left sided in 45% (21/47) of cases (15 lateral, one anterior, three posteroseptal, and two posterolateral) and right sided in 55% (26/47; one anterior, three anterolateral, one posterolateral, three lateral, five para-Hisian, 12 posteroseptal, and one anteroseptal). Ablation without the use of fluoroscopy was successfully performed in every patient (33 with RF and in 11 with cryoenergy). No complication occurred. At a mean follow-up of 16.0 ± 11.7 months, we observed seven recurrences, three of them successfully re-ablated without fluoroscopy. In one case cryoablation of a para-Hisian AP was ineffective in the long term. CONCLUSIONS: Three-dimensional EAM allowed a safe and effective fluoroless AP ablation procedure in a pediatric population both with RF and cryoenergy.

Very long-term results of electroanatomic-guided radiofrequency ablation of atrial arrhythmias in patients with surgically corrected atrial septal defect.

AIMS: Atrial tachycardias are common after repair of atrial septal defect (ASD). Although ablation has shown promising results in the short and mid-term follow-up, little data regarding the very long-term success exist. Our aim was to assess very long-term follow-up in patients who have undergone electroanatomic-guided radiofrequency (RF) ablation of late-onset atrial arrhythmias after ASD surgery. METHODS AND RESULTS: Forty-six consecutive patients with surgically repaired ASD were referred for atrial tachycardia ablation. Electrophysiological (EP) study and ablation procedure with the aid of an electroanatomic mapping (EAM) system were performed. Mean age was 49 ± 13 years (females 61%). The presenting arrhythmias were typical atrial flutter (48%), atypical atrial flutter (35%), and atrial tachycardia (17%). In 41% of patients, atrial fibrillation was also present. The EP study showed a right atrial macroreentrant circuit in all the patients. In 12 of 46 (26%), the circuit was localized in the cavo-tricuspid isthmus, whereas in the remaining 34 patients (74%) was atriotomy-dependent. Acute success was 100%. Clinical arrhythmia recurred in 24% of the patients. Nine patients underwent a second and two a third ablation procedure, reaching an overall efficacy of 87% (40 of 46) at a mean follow-up of 7.3 ± 3.8 years since the last procedure. With antiarrhythmic drugs the success rate increased to 96% (44 of 46). No complications occurred. CONCLUSION: In patients with surgically corrected ASD, EAM-guided RF ablation of late-onset macroreentrant atrial arrhythmias demonstrated a high success rate in a very long-term follow-up. Therefore, RF ablation could be considered early in the management of late-onset macroreentrant atrial tachycardias.

Prevalence of silent cerebral ischemia in paroxysmal and persistent atrial fibrillation and correlation with cognitive function.

OBJECTIVES: The aim of this study was to compare the prevalence of silent cerebral ischemia (SCI) and cognitive performance in patients with paroxysmal and persistent atrial fibrillation (AF) and controls in sinus rhythm. BACKGROUND: Large registries have reported a similar risk for symptomatic stroke in both paroxysmal and persistent AF. The relationship among paroxysmal and persistent AF, SCI, and cognitive impairment has remained uncharted. METHODS: Two hundred seventy subjects were enrolled: 180 patients with AF (50% paroxysmal and 50% persistent) and 90 controls. All subjects underwent clinical assessment, neurological examination, cerebral magnetic resonance, and the Repeatable Battery for the Assessment of Neuropsychological Status. RESULTS: At least 1 area of SCI was present in 80 patients (89%) with paroxysmal AF, 83 (92%) with persistent AF (paroxysmal vs. persistent, p = 0.59), and 41 (46%) controls (paroxysmal vs. controls and persistent vs. controls, p < 0.01). The number of areas of SCI per subject was higher in patients with persistent AF than in those with paroxysmal AF (41.1 ± 28.0 vs. 33.2 ± 22.8, p = 0.04), with controls reporting lower figures (12.0 ± 26.7, p < 0.01 for both). Cognitive performance was significantly worse in patients with persistent and paroxysmal AF than in controls (Repeatable Battery for the Assessment of Neuropsychological Status scores 82.9 ± 11.5, 86.2 ± 13.8, and 92.4 ± 15.4 points, respectively, p < 0.01). CONCLUSIONS: Patients with paroxysmal and persistent AF had a higher prevalence and number of areas of SCI per patient than controls and worse cognitive performance than subjects in sinus rhythm.

Single center experience of fluoroless AVNRT ablation guided by electroanatomic reconstruction in children and adolescents.

BACKGROUND: Anatomical considerations and risks related to x-ray exposure make atrioventricular nodal reentrant tachycardia (AVNRT) ablation in pediatric patients a concerning procedure. We aimed to evaluate the feasibility, safety, and efficacy of performing fluoroless slow-pathway cryoablation guided by the electroanatomic (EA) mapping in children and adolescents. METHODS: Twenty-one consecutive patients (mean age 13.5 ± 2.4 years) symptomatic for AVNRT were prospectively enrolled to right atrium EA mapping and electrophysiological study prior to cryoablation. Cryoablation was guided by slow-pathway potential and performed using a 4-mm-tip catheter. RESULTS: Sustained slow-fast AVNRT was inducible in all the patients with a dual AV nodal physiology in 95%. Acute success was achieved in 100% of the patients with a median of two cryo-applications. Fluoroless ablation was feasible in 19 patients, while in two subjects 50 seconds and 45 seconds of x-ray were needed due to difficult progression of the catheters along the venous system. After a mean follow-up of 25 months, AVNRT recurred in five patients. All the recurrences were successfully treated with a second procedure. In three patients, a fluoroless cryoablation with a 6-mm-tip catheter was successfully performed, while in the remaining two patients, a single pulse of 60 seconds of radiofrequency energy was applied under fluoroscopic monitoring. No complications occurred. CONCLUSIONS: Combination of EA mapping systems and cryoablation may allow to perform fluoroless slow-pathway ablation for AVNRT in children and adolescents in the majority of patients. Fluoroless slow-pathway cryoablation showed a high efficacy and safety comparable to conventional fluoroscopy guided procedures.

Impact of ablation catheter irrigation design on silent cerebral embolism after radiofrequency catheter ablation of atrial fibrillation: results from a pilot study.

INTRODUCTION: Silent cerebral lesions (SCL) are a sensitive tool to evaluate thromboembolic risk of catheter ablation. Recent data showed the possibility to reduce thrombus formation when the electrode-tissue interface cooling is optimized by a homogeneous flushing of saline along the entire surface of the distal electrode through a larger number of irrigation holes. The study aim is to compare procedural parameters and safety of pulmonary vein isolation (PVI) performed by using open-irrigated catheters with different irrigation design. METHODS AND RESULTS: Eighty patients (74% males; age 57 ± 12 years) with paroxysmal AF randomly underwent PVI performed with a new irrigation design catheter (group A, 40 patients) versus a standard irrigated catheter (group B, 40 patients). A cerebral magnetic resonance imaging (MRI) was performed before and after the procedure. Postprocedural brain MRI unveiled SCL in 2 patients in group A and in 3 in group B (5% vs 7.5%, P = 0.500). Intraprocedural ACT was the only independent factor associated with the occurrence of SCL (OR = 0.996; 95% CI 0.994-0.998, P < 0.001). Among procedural parameters, we observed a reduction of irrigation saline volume of 662 mL in group A versus group B (P < 0.001). CONCLUSION: PVI performed with a new irrigated catheter did not reduce significantly the SCL risk when compared to a standard irrigated catheter. Intraprocedural ACT reduces the SCL risk of 0.4% for each point of ACT increase. For ACT > 320 seconds no SCL occurred. Finally, compared to a standard irrigated catheter, PVI performed with a new irrigation design catheter reduces significantly saline volume infusion.

Delaying cardioversion following 4-week anticoagulation in case of persistent atrial fibrillation after a transcatheter ablation procedure to reduce silent cerebral thromboembolism: a single-center pilot study.

BACKGROUND: Symptomatic cerebral thromboembolism occurs in 0.4% of transcatheter atrial fibrillation ablation procedures. Silent cerebral events, instead, have recently been reported in up to 14%, especially clustered within patients undergoing cardioversion at the end of the procedure. The present study reports the incidence of silent cerebral thromboembolism, assessed by cerebral MRI, delaying electrical cardioversion, in case of lack of sinus rhythm restoration at the end of the procedure, after 4 weeks of effective anticoagulation. METHODS AND RESULTS: Ninety-five consecutive patients with antiarrhythmic drug refractory atrial fibrillation were referred for transcatheter ablation and enrolled in the study. All patients underwent pre-ablation and post-ablation cerebral MRI. Overall, post-ablation cerebral MRI registered new thromboembolism in six (6%) patients. Fifty-five (58%) patients remained in sinus rhythm throughout the procedure and 40 (42%) reported persistent atrial fibrillation, yielding a silent thromboembolism incidence of 5 and 8%, respectively. In particular, silent thromboembolism was registered in one (4%) of the 25 patients achieving sinus rhythm by catheters, in two (18%) of the 11 patients spontaneously restoring sinus rhythm shortly following the procedure and in none of the four patients cardioverted following 4-week anticoagulation. In a matched reference population, a significantly higher percentage of patients (15, 16% vs. 6, 6%; P = 0.03) suffered from a new post-ablation thromboembolism; particularly within patients terminating the procedure in atrial fibrillation. Delaying cardioversion reduced silent cerebral thromboembolism from 38 to 13%. CONCLUSION: Delaying electrical cardioversion after a 4-week anticoagulation period reduced the risk of silent cerebral thromboembolism and is a viable and safer option in patients terminating a transcatheter ablation procedure in atrial fibrillation.