Catheter Ablation of Atrioventricular Nodal Reentrant Tachycardia in Patients With Congenital Heart Disease.

Atrioventricular (AV) nodal reentrant tachycardia represents the most common regular supraventricular arrhythmia in humans, and catheter ablation of the so called slow AV nodal pathway has been effectively performed for decades. In patients with congenital heart disease, a combination of different factors makes catheter ablation of AV nodal reentrant tachycardia substrate particularly challenging, including abnormal venous access to intracardiac structures, abnormal intracardiac anatomy, potentially deviant and often unpredictable sites of the specific conduction system, loss of traditional anatomic landmarks, and congenital cardiac surgery that may complicate the access to the AV nodal area. Published experiences have confirmed the efficacy and the relative safety of such procedures when performed by experts, but the risk of complications, in particular AV block, remains non-negligible. A thorough knowledge and understanding of anatomic and electrical specificities according to underlying phenotype are essential in addressing these complex cases. Considering the major consequences associated with AV block in patients with complex congenital heart disease, particularly those without low risk access for transvenous ventricular pacing (eg, single ventricle physiology or Eisenmenger syndrome), the individual risk-benefit ratio should be carefully evaluated. The decision to defer ablation may be the wisest approach in selected patients with either infrequent or hemodynamically tolerated arrhythmias, or when the location of the AV conduction pathways remains uncertain. This narrative review aims to synthetize existing literature on catheter ablation of AV nodal reentrant tachycardia in congenital heart disease, to present main features of common associated pathologies, and to discuss approaches to mapping and safely ablating the slow AV nodal pathway in challenging cases.

Predicting Survival in Repaired Tetralogy of Fallot: A Lesion-Specific and Personalized Approach.

OBJECTIVES: This study sought to identify patients with repaired tetralogy of Fallot (rTOF) at high risk of death and malignant ventricular arrhythmia (VA). BACKGROUND: To date there is no robust risk stratification scheme to predict outcomes in adults with rTOF. METHODS: Consecutive patients were prospectively recruited for late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) to define right and left ventricular (RV, LV) fibrosis in addition to proven risk markers. RESULTS: The primary endpoint was all-cause mortality. Of the 550 patients (median age 32 years, 56% male), 27 died (mean follow-up 6.4 ± 5.8; total 3,512 years). Mortality was independently predicted by RVLGE extent, presence of LVLGE, RV ejection fraction ≤47%, LV ejection fraction ≤55%, B-type natriuretic peptide ≥127 ng/L, peak exercise oxygen uptake (V02) ≤17 mL/kg/min, prior sustained atrial arrhythmia, and age ≥50 years. The weighted scores for each of the preceding independent predictors differentiated a high-risk subgroup of patients with a 4.4%, annual risk of mortality (area under the curve [AUC]: 0.87; P < 0.001). The secondary endpoint (VA), a composite of life-threatening sustained ventricular tachycardia/resuscitated ventricular fibrillation/sudden cardiac death occurred in 29. Weighted scores that included several predictors of mortality and RV outflow tract akinetic length ≥55 mm and RV systolic pressure ≥47 mm Hg identified high-risk patients with a 3.7% annual risk of VA (AUC: 0.79; P < 0.001) RVLGE was heavily weighted in both risk scores caused by its strong relative prognostic value. CONCLUSIONS: We present a score integrating multiple appropriately weighted risk factors to identify the subgroup of patients with rTOF who are at high annual risk of death who may benefit from targeted therapy.

Radiation Safety and Electrophysiologists: Radiation Protection Status - Go for Zero Fluoroscopy European Heart Rhythm Association Registry.

BACKGROUND: The purpose of this study was to analyze electrophysiologists' radiation-protective devices for occupational exposure across European countries. METHODS: Data reported herein were gathered from the international, multicenter prospective Go for Zero Fluoroscopy registry performed in years 2018-2019. The registry encompassed 25 European electrophysiological centers from 14 countries and up to 5 operators from each center. RESULTS: The analysis included 95 operators (median age: 39 years, 85% of male, median training time: 5 years). The most frequently used X-ray protection tools (used by ≥80% of the group) were lead aprons, thyroid shields, screens below the table, glass in the laboratory, and least often (<7%) protective gloves and cabin. No statistically significant differences regarding the number of procedures performed monthly, electrophysiologists' experience and gender, and radiation exposure dose or radiation protection tools were observed, except lead thyroid shields and eyeglasses, which were more often used in case of fewer electrophysiological procedures performed (<20 procedures per month). Operators who were protected by >4 X-ray protection tools were exposed to lower radiation levels than those who were protected by ≤4 X-ray protection tools (median radiation exposure: 0.6 [0.2-1.1] vs. 0.2 [0.1-0.2] mSv per month, p < 0.0001; 1.1 [0.1-12.0] vs. 0.5 [0.1-1.1] mSv per year, p < 0.0001), respectively. CONCLUSIONS: Electrophysiologists' radiation-protective devices for occupational exposure are similar across European centers and in accordance with the applicable X-ray protection protocols, irrespective of the level of experience, number of monthly performed EP procedures, and gender.

Catheter mapping and ablation during pregnancy.

A substantial number of pregnant women at some point experience cardiac arrhythmia, which is mostly treated by antiarrhythmic medication. In some instances, arrhythmias can be drug-resistant and pose a relevant risk to both mother and unborn child as they can result in hemodynamic compromise. In recent years, invasive electrophysiology procedures have been carried out with ever reducing exposure to ionising radiation, and multiple techniques have been established to achieve ZERO exposure. Of course, these techniques should all be applied when contemplating an invasive mapping and ablation procedure during pregnancy. The role of the cardio-obstetrics team in planning and performing such procedures is paramount. Careful assessment of the pregnant mother and her unborn child is mandatory. Only with good preparation is a complete understanding of both cardiac anatomy and physiology achievable, which is a pre-requisite of a successful ablation outcome. Various aspects of the ablation procedure itself are discussed and evaluated from the perspective of all team members involved, including the obstetrician, the anaesthetist and the electrophysiologist. This review aims to inform the reader about the techniques available and reports on the published outcomes for ablations during pregnancy in the last decade.

Erratum: Trends of renal diseases in Germany: review of a regional renal biopsy database from 1990 to 2013.

[This corrects the article DOI: 10.1093/ckj/sfz023.][This corrects the article DOI: 10.1093/ckj/sfz023.].

Fluoroscopy usage in contemporary interventional electrophysiology: Insights from a European registry.

BACKGROUND: Fluoroscopy has been an essential part of every electrophysiological procedure since its inception. However, till now no clear standards regarding acceptable x-ray exposure nor recommendation how to achieve them have been proposed. HYPOTHESIS: Current norms and quality markers required for optimal clinical routine can be identified. METHODS: Centers participating in this Europe-wide multicenter, prospective registry were requested to provide characteristics of the center, operators, technical equipment as well as procedural settings of consecutive cases. RESULTS: Twenty-five centers (72% university clinics, with a mean volume of 526 ± 348 procedures yearly) from 14 European countries provided data on 1788 cases [9% diagnostic procedures (DP), 38% atrial fibrillation (AF) ablations, 44% other supraventricular (SVT) ablations, and 9% ventricular ablations (VT)] conducted by 95 operators (89% male, 41 ± 7 years old). Mean dose area product (DAP) and time was 304 ± 608 cGy*cm2 , 3.6 ± 4.8 minutes, 1937 ± 608 cGy*cm2 , 15.3 ± 15.5 minutes, 805 ± 1442 cGy*cm2 , 10.6 ± 10.7 minutes, and 1277 ± 1931 cGy*cm2 , 10.4 ± 12.3 minutes for DP, AF, SVT, and VT ablations, respectively. Seven percent of all procedures were conducted without any use of fluoroscopy. Procedures in the lower quartile of DAP were performed more frequently by female operators (OR 1.707, 95%CI 1.257-2.318, P = .001), in higher-volume center (OR 1.001 per one additional procedure, 95%CI 1.000-1.001, P = .002), with the use of 3D-mapping system (OR 2.622, 95%CI 2.053-3.347, P < .001) and monoplane x-ray system (OR 2.945, 95%CI 2.149-4.037, P < .001). CONCLUSION: Exposure to ionizing radiation varies widely in daily practice for all procedure. Significant opportunities for harmonization of exposure toward the lower range has been identified.

Association Between Dietary Patterns and Kidney Function in Patients With Chronic Kidney Disease: A Cross-Sectional Analysis of the German Chronic Kidney Disease Study.

OBJECTIVE: In the general population, "healthy" dietary patterns are associated with improved health outcomes, but data on associations between observance of specific dietary patterns and kidney function in patients with chronic kidney disease (CKD) are sparse. METHODS: Dietary intake was evaluated using food frequency questionnaires in patients with moderately severe CKD under nephrology care enrolled into the observational multicenter German CKD study. The Dietary Approaches to Stop Hypertension (DASH) diet score, Mediterranean diet score, and German Food Pyramid Index (GFPI) were calculated and their association with estimated glomerular filtration rate (eGFR) and albuminuria was assessed by multivariable linear regression analysis, adjusted for gender, age, body mass index, energy intake, smoking status, alcohol intake, education, high-density lipoprotein-cholesterol (HDL- cholesterol), low-density lipoprotein-cholesterol (LDL-cholesterol), hypertension, and diabetes mellitus. RESULTS: A total of 2,813 patients (41% women; age 60.1 ± 11.6 years) were included in the analysis. High DASH diet score and GFPI were associated with lower systolic blood pressure and lower intake of antihypertensive medication, higher HDL, and lower uric acid levels. Mediterranean-style diet was associated with lower prevalence of diabetes mellitus. Higher DASH and Mediterranean diet scores were associated with higher eGFR (ß-coefficient = 1.226, P < .001; ß-coefficient = 0.932, P = .007, respectively). In contrast, GFPI was not associated with eGFR. For the individual components of the dietary patterns, higher intake of nuts and legumes, cereals, fish, and polyunsaturated fats was associated with higher eGFR and higher intake of dairy, composed of low- and whole-fat dairy, was associated with lower eGFR. No association was found between dietary patterns and albuminuria. CONCLUSION: Higher observance of the DASH or Mediterranean diet, but not German food pyramid recommendations, was associated with higher eGFR among patients with CKD. Improving dietary habits may offer an opportunity to better control comorbidities and kidney function decline in patients with CKD.

Catheter ablation for patients with end-stage complex congenital heart disease or cardiomyopathy considered for transplantation: Trials and tribulations.

INTRODUCTION: Arrhythmia contributes significantly to morbidity and mortality of patients with congenital heart disease (CHD) or cardiomyopathy (CMP). It also has the potential to worsen symptoms and is particularly detrimental to patients with advanced heart failure awaiting cardiac transplantation. We report our experience using catheter ablation to treat recurrent arrhythmia in patients with CHD or CMP considered for transplantation. METHODS: Five consecutive patients (3 female, mean age 47.8 ±â€¯12.8 years) with complex CHD or CMP (tricuspid atresia, mitral atresia, double inlet left ventricle, arrhythmogenic right ventricular cardiomyopathy, left ventricular non-compaction) presented with either atrial (n = 3) or ventricular (n = 2) arrhythmias. All ablations were guided by three-dimensional (3D) electro-anatomical mapping, plus remote magnetic navigation in 3 patients. RESULTS: Patients underwent a median of 2 ablation procedures for a total number of 26 tachycardias. None of the 5 patients experienced further arrhythmia at a median of 939 days (range 4-1375) from their last ablation. During a median follow up of 31 months (range 1-70), three patients underwent successful transplantation at 1375, 1062 and 321 days following their last ablation. One patient with a Fontan circulation died from hepatic cancer and one from end-stage heart failure despite urgent transplant listing. CONCLUSIONS: Catheter ablation is feasible in complex cardiac patients considered for heart transplantation and should be offered for rhythm management and patient optimization until a suitable donor is found.

Trends of renal diseases in Germany: review of a regional renal biopsy database from 1990 to 2013.

BACKGROUND: Several renal biopsy registries in Europe have shown geographical and temporal variations in the patterns of renal diseases. However, there is a lack of current data on trends of renal disease in Central Europe. METHODS: After exclusion of transplant and re-biopsies, the renal biopsy registry of the German RWTH Aachen University Hospital included data of 1208 biopsies over a period of 24 years (1990-2013). Trends in the biopsy rate and diagnosis of glomerular diseases were analysed. RESULTS: The average annual biopsy incidence was 6.1 biopsies per 100 000 population. The frequency of kidney biopsies increased significantly over the years (P < 0.001). Primary glomerulonephritis (GN) accounted for nearly two-thirds (58.4%) of all native kidney biopsies, and immunoglobulin A-nephropathy (IgAN) was the leading histological diagnosis (34.7%) followed by necrotizing GN (RPGN) at 18.7%. IgAN increased 2-fold over the study periods (+195%, P < 0.001). Focal segmental glomerulosclerosis accounted for 6.1% of all diagnoses, and its frequency rose to 3.9-fold (+388%, P < 0.001). Lupus nephritis showed a doubling in incidence (P = 0.0499), while acute tubular necrosis decreased to 3.5-fold (P = 0.0008). All other disease entities failed to exhibit linear trends over time. In children, the most common pathologies were IgAN (26.1%) and minimal change disease (21.7%), whereas RPGN (19.4%) dominated in the group of patients >60 years. CONCLUSION: IgAN was the most common primary glomerular disease in our centre and its prevalence increased over 24 years.

Efficacy of catheter ablation for atrial fibrillation in patients with congenital heart disease.

AIMS: Advances in surgical techniques allow an increasing number of children with congenital heart disease (CHD) to reach adulthood. As patients grow older, atrial fibrillation (AF) is evolving into a major clinical concern and can be difficult to manage medically. Primary AF catheter ablation may, therefore, have a role in this setting but few reports have evaluated its efficacy in CHD patients. METHODS AND RESULTS: We retrospectively reviewed 58 consecutive patients [median age 51, interquartile range (IQR) 44-63 years, 57% male] with AF (45% paroxysmal) who underwent 122 ablation procedures in our tertiary centre in the last decade. The majority had CHD of moderate or severe complexity (57%, Bethesda Class 2 or 3) with a dilated left atrium (LA) (81%) and/or right atrium (86%). At 1-year from the first ablation, 32.8% of patients remained in sinus rhythm. Multiple procedures were required in 35 (60%) patients. Freedom from AF at 1-year after the 2nd and 3rd ablation was 40.9% and 36.5%, respectively. Multivariable predictors of AF recurrence were underlying anatomic complexity [hazard ratio (HR) in Bethesda 3 1.98, P = 0.006], type of AF (HR for persistent 1.87, P = 0.004), and indexed LA dimensions (HR for cm2/m2 1.06, P = 0.03). CONCLUSION: While ablation may be a valid option for the treatment of AF in CHD patients, multiple procedures are likely to be required. Early referral and careful patient selection are essential to optimize the results of AF ablation, achieving a low rate of recurrence. Further studies are needed to validate our prognostic model and guide clinical practice.

Respiratory and cardiovascular responses to walking down a traffic-polluted road compared with walking in a traffic-free area in participants aged 60 years and older with chronic lung or heart disease and age-matched healthy controls: a randomised, crossover study.

BACKGROUND: Long-term exposure to pollution can lead to an increase in the rate of decline of lung function, especially in older individuals and in those with chronic obstructive pulmonary disease (COPD), whereas shorter-term exposure at higher pollution levels has been implicated in causing excess deaths from ischaemic heart disease and exacerbations of COPD. We aimed to assess the effects on respiratory and cardiovascular responses of walking down a busy street with high levels of pollution compared with walking in a traffic-free area with lower pollution levels in older adults. METHODS: In this randomised, crossover study, we recruited men and women aged 60 years and older with angiographically proven stable ischaemic heart disease or stage 2 Global initiative for Obstructive Lung Disease (GOLD) COPD who had been clinically stable for 6 months, and age-matched healthy volunteers. Individuals with ischaemic heart disease or COPD were recruited from existing databases or outpatient respiratory and cardiology clinics at the Royal Brompton & Harefield NHS Foundation Trust and age-matched healthy volunteers using advertising and existing databases. All participants had abstained from smoking for at least 12 months and medications were taken as recommended by participants' doctors during the study. Participants were randomly assigned by drawing numbered disks at random from a bag to do a 2 h walk either along a commercial street in London (Oxford Street) or in an urban park (Hyde Park). Baseline measurements of participants were taken before the walk in the hospital laboratory. During each walk session, black carbon, particulate matter (PM) concentrations, ultrafine particles, and nitrogen dioxide (NO2) concentrations were measured. FINDINGS: Between October, 2012, and June, 2014, we screened 135 participants, of whom 40 healthy volunteers, 40 individuals with COPD, and 39 with ischaemic heart disease were recruited. Concentrations of black carbon, NO2, PM10, PM2.5, and ultrafine particles were higher on Oxford Street than in Hyde Park. Participants with COPD reported more cough (odds ratio [OR] 1·95, 95% CI 0·96-3·95; p<0·1), sputum (3·15, 1·39-7·13; p<0·05), shortness of breath (1·86, 0·97-3·57; p<0·1), and wheeze (4·00, 1·52-10·50; p<0·05) after walking down Oxford Street compared with Hyde Park. In all participants, irrespective of their disease status, walking in Hyde Park led to an increase in lung function (forced expiratory volume in the first second [FEV1] and forced vital capacity [FVC]) and a decrease in pulse wave velocity (PWV) and augmentation index up to 26 h after the walk. By contrast, these beneficial responses were attenuated after walking on Oxford Street. In participants with COPD, a reduction in FEV1 and FVC, and an increase in R5-20 were associated with an increase in during-walk exposure to NO2, ultrafine particles and PM2.5, and an increase in PWV and augmentation index with NO2 and ultrafine particles. In healthy volunteers, PWV and augmentation index were associated both with black carbon and ultrafine particles. INTERPRETATION: Short-term exposure to traffic pollution prevents the beneficial cardiopulmonary effects of walking in people with COPD, ischaemic heart disease, and those free from chronic cardiopulmonary diseases. Medication use might reduce the adverse effects of air pollution in individuals with ischaemic heart disease. Policies should aim to control ambient levels of air pollution along busy streets in view of these negative health effects. FUNDING: British Heart Foundation.

An efficient cardiac mapping strategy for radiofrequency catheter ablation with active learning.

OBJECTIVE: A major challenge in radiofrequency catheter ablation procedures is the voltage and activation mapping of the endocardium, given a limited mapping time. By learning from expert interventional electrophysiologists (operators), while also making use of an active-learning framework, guidance on performing cardiac voltage mapping can be provided to novice operators or even directly to catheter robots. METHODS: A learning from demonstration (LfD) framework, based upon previous cardiac mapping procedures performed by an expert operator, in conjunction with Gaussian process (GP) model-based active learning, was developed to efficiently perform voltage mapping over right ventricles (RV). The GP model was used to output the next best mapping point, while getting updated towards the underlying voltage data pattern as more mapping points are taken. A regularized particle filter was used to keep track of the kernel hyperparameter used by GP. The travel cost of the catheter tip was incorporated to produce time-efficient mapping sequences. RESULTS: The proposed strategy was validated on a simulated 2D grid mapping task, with leave-one-out experiments on 25 retrospective datasets, in an RV phantom using the Stereotaxis Niobe® remote magnetic navigation system, and on a tele-operated catheter robot. In comparison with an existing geometry-based method, regression error was reduced and was minimized at a faster rate over retrospective procedure data. CONCLUSION: A new method of catheter mapping guidance has been proposed based on LfD and active learning. The proposed method provides real-time guidance for the procedure, as well as a live evaluation of mapping sufficiency.

[Arrhythmia in adults with congenital heart defects : Atrial tachycardia]. / Arrhythmien bei Erwachsenen mit angeborenen Herzfehlern : Atriale Tachykardien.

Atrial arrhythmias are frequently encountered in patients with congenital heart disease (CHD) with or without corrective surgery and respond to pharmacological therapies with only limited success. This review describes the technologies currently available for performing successful ablation procedures in this very complex patient cohort. In addition to an understanding of the underlying anatomy, which can be supplemented by 3D imaging with the aid of magnetic resonance imaging (MRI) or computed tomography (CT), the choice between the different 3D mapping systems (sequential versus simultaneous) is presented. Finally, conventional manual navigation is compared with magnetic navigation and then discussed with regard to the respective arrhythmias encountered with the different forms of CHD.

Remote Magnetic Navigation for Catheter Ablation in Patients With Congenital Heart Disease: A Review.

In patients with congenital heart disease, challenges to catheter-based arrhythmia interventions are unique and numerous given the complexity of the underlying defects, anatomic and surgical intervention variants including baffles, conduits, patches, and/or shunts. Remote magnetic navigation offers significant advantages in these cases that may present with limited vascular access or difficult access to the target cardiac chambers implicated by the previous surgical interventions. We reviewed the data available on the safety, feasibility, and effectiveness of magnetic navigation for the treatment of arrhythmia in congenital heart disease and discussed the specific challenges related to various congenital defects and repair with the potential advantages offered by magnetic navigation in these circumstances.

Epicardial ablation of ventricular tachycardia in a patient with arrhythmogenic right ventricular dysplasia after failed conventional endocardial ablation: A case for remote navigation with functional image integration.

Arrhythmogenic right ventricular dysplasia (ARVD) is an inheritable heart muscle disease that predominantly affects the right ventricle (RV) and predisposes to ventricular arrhythmias and sudden cardiac death (SCD)1. The natural history is predominantly related to ventricular electric instability which may lead to arrhythmic SCD, mostly in young people and athletes2,3, but may progress with significant RV muscle disease and left-ventricular (LV) involvement and can result in right or biventricular heart failure4. We report on a 54-year-old male with ARVD who underwent an epicardial ventricular tachycardia (VT) ablation using remote magnetic navigation (RMN) after functional imaging from a nuclear perfusion study was fused with a 3D segmentation from computed tomography (CT) imaging.

Juxtaposition of the atrial appendages: A nidus for thrombus in atriopulmonary Fontan?

Juxtaposition of atrial appendages is a rare cardiac congenital anomaly, usually associated with other cardiac malformations. Until now, it has not been linked to any significant clinical implications. We report cardiovascular magnetic resonance (CMR) findings of two adult patients who underwent atriopulmonary Fontan operation in the setting of left juxtaposition of the atrial appendages. The patients were in sinus rhythm at the time of the CMR study. Both patients had episodes of sustained atrial tachyarrhythmia requiring electrical cardioversion and were anticoagulated with warfarin with target INR 2-3. CMR images showed a thrombus located in the enlarged and juxtaposed right appendage in both patients. Blood flow frequently appears slow or sluggish in the dilated right atrium following atriopulmonary Fontan surgery. In addition, cine CMR suggested that blood flow reaches very low velocities in the massively dilated juxtaposed right atrial appendage cul-de-sac, thus potentially creating a substrate for clot formation. These findings propose that juxtaposed atrial appendages in atriopulmonary Fontan is an additional risk factor for clot formation, specifically in the dilated right atrial appendage on the left side juxtaposed with the left atrial appendage and that prophylactic anticoagulation is highly justified in these patients.