Spotlight on S-ICD™ therapy: 10 years of clinical experience and innovation.

Subcutaneous ICD (S-ICD™) therapy has been established in initial clinical trials and current international guideline recommendations for patients without demand for pacing, cardiac resynchronization, or antitachycardia pacing. The promising experience in 'ideal' S-ICD™ candidates increasingly encourages physicians to provide the benefits of S-ICD™ therapy to patients in clinical constellations beyond 'classical' indications of S-ICD™ therapy, which has led to a broadening of S-ICD™ indications in many centres. However, the decision for S-ICD™ implantation is still not covered by controlled randomized trials but rather relies on patient series or observational studies. Thus, this review intends to give a contemporary update on available empirical evidence data and technical advancements of S-ICD™ technology and sheds a spotlight on S-ICD™ therapy in recently discovered fields of indication beyond ideal preconditions. We discuss the eligibility for S-ICD™ therapy in Brugada syndrome as an example for an adverse and dynamic electrocardiographic pattern that challenges the S-ICD™ sensing and detection algorithms. Besides, the S-ICD™ performance and defibrillation efficacy in conditions of adverse structural remodelling as exemplified for hypertrophic cardiomyopathy is discussed. In addition, we review recent data on potential device interactions between S-ICD™ systems and other implantable cardio-active systems (e.g. pacemakers) including specific recommendations, how these could be prevented. Finally, we evaluate limitations of S-ICD™ therapy in adverse patient constitutions, like distinct obesity, and present contemporary strategies to assure proper S-ICD™ performance in these patients. Overall, the S-ICD™ performance is promising even for many patients, who may not be 'classical' candidates for this technology.

Use of direct oral anticoagulants in patients on chronic hemodialysis: Contemporary appraisal on the role for patients with atrial fibrillation.

Atrial fibrillation (AF) is common in patients with chronic kidney disease (CKD) undergoing hemodialysis and in this patient population, management in terms of oral anticoagulation (OAC) presents unique challenges due to the increased risk of both thromboembolic events and bleeding complications. The attributable risk of AF for stroke may differ from patients without CKD, raising the question if OAC is indicated at all. Historically, vitamin K antagonists (VKA) have been the standard treatment for anticoagulation in AF; however, direct oral anticoagulants (DOACs) have emerged as an alternative therapeutic option, whereby data from prospective randomised trials with hemodialysis patients is limited resulting in great variability of practice and guideline recommendations. This review summarizes existing data sources regarding the use and benefit of oral anticoagulation with VKA and DOAC in hemodialysis patients.

Incidence and predictors of cardiac arrhythmias in patients with COVID-19 induced ARDS.

INTRODUCTION: Recent studies suggest cardiac involvement with an increased incidence of arrhythmias in the setting of coronavirus disease 2019 (COVID-19). The aim of this study was to evaluate the risk of potentially lethal arrhythmias and atrial fibrillation in patients with COVID-19-induced acute respiratory distress syndrome (ARDS) and to elicit possible predictors of arrhythmia occurrence. METHODS AND RESULTS: A total of 107 patients (82 male, mean age 60 ±â€¯12 years, median body mass index 28 kg/m2) treated for COVID-19-induced ARDS in a large tertiary university hospital intensive care unit between March 2020 and February 2021 were retrospectively analyzed. Eighty-four patients (79%) had at least moderate ARDS, 88 patients (83%) were mechanically ventilated, 35 patients (33%) received vvECMO. Forty-three patients (40%) died during their hospital stay. Twelve patients (11%) showed potentially lethal arrhythmias (six ventricular tachycardia, six significant bradycardia). Atrial fibrillation occurred in 27 patients (25%). In a multivariate logistic regression analysis, duration of hospitalization was associated with the occurrence of potentially lethal arrhythmias (p = 0.006). There was no association between possible predictive factors and the occurrence of atrial fibrillation. Invasive ventilation, antipsychotics, and the QTc interval were independently associated with acute in-hospital mortality, but this was not arrhythmia-driven as there was no association between the occurrence of arrhythmias and mortality. CONCLUSION: In this relatively young population with COVID-19-induced ARDS, the incidence of potentially lethal arrhythmias was low. While overall mortality was high in these severely affected patients, cardiac involvement and arrhythmia occurrence was not a significant driver of mortality.

Accuracy of Deep Learning Echocardiographic View Classification in Patients with Congenital or Structural Heart Disease: Importance of Specific Datasets.

INTRODUCTION: Automated echocardiography image interpretation has the potential to transform clinical practice. However, neural networks developed in general cohorts may underperform in the setting of altered cardiac anatomy. METHODS: Consecutive echocardiographic studies of patients with congenital or structural heart disease (C/SHD) were used to validate an existing convolutional neural network trained on 14,035 echocardiograms for automated view classification. In addition, a new convolutional neural network for view classification was trained and tested specifically in patients with C/SHD. RESULTS: Overall, 9793 imaging files from 262 patients with C/SHD (mean age 49 years, 60% male) and 62 normal controls (mean age 45 years, 50.0% male) were included. Congenital diagnoses included among others, tetralogy of Fallot (30), Ebstein anomaly (18) and transposition of the great arteries (TGA, 48). Assessing correct view classification based on 284,250 individual frames revealed that the non-congenital model had an overall accuracy of 48.3% for correct view classification in patients with C/SHD compared to 66.7% in patients without cardiac disease. Our newly trained convolutional network for echocardiographic view detection based on over 139,910 frames and tested on 35,614 frames from C/SHD patients achieved an accuracy of 76.1% in detecting the correct echocardiographic view. CONCLUSIONS: The current study is the first to validate view classification by neural networks in C/SHD patients. While generic models have acceptable accuracy in general cardiology patients, the quality of image classification is only modest in patients with C/SHD. In contrast, our model trained in C/SHD achieved a considerably increased accuracy in this particular cohort.

Proarrhythmic Effect of Acetylcholine-Esterase Inhibitors Used in the Treatment of Alzheimer's Disease: Benefit of Rivastigmine in an Experimental Whole-Heart Model.

Several studies suggest QT prolongation and torsade de pointes with acetylcholine-esterase inhibitors. We therefore examined the electrophysiologic profile of donepezil, rivastigmine, and galantamine in a sensitive whole-heart model of proarrhythmia. 34 rabbit hearts were isolated and retrogradely perfused employing the Langendorff setup. Hearts were treated either with donepezil, rivastigmine, or galantamine in rising concentrations and electrophysiologic studies were performed. In the presence of donepezil and galantamine, spatial dispersion of repolarization was amplified. Cardiac repolarization (QT interval and action potential duration) was prolonged with donepezil but not with galantamine. Remarkably, both drugs induced triggered activity (early afterdepolarizations and torsade de pointes tachycardia). Despite a pronounced prolongation of repolarization with rivastigmine, no increase in spatial dispersion of repolarization and thus no triggered activity was observed. In the present study, donepezil and galantamine provoked triggered activity, whereas rivastigmine did not have proarrhythmic effects. Spatial dispersion of repolarization but not duration of cardiac repolarization was associated with increased risk of drug-induced proarrhythmia with acetylcholine-esterase inhibitors. Consequently, QT interval duration might be insufficient to estimate the risk of proarrhythmia with acetylcholine-esterase inhibitors. Our findings emphasize the need for further electrocardiographic risk predictors.

[Cardiac arrhythmias in patients with chronic kidney disease]. / Rhythmusstörungen bei Nierenerkrankungen und Nierenersatzverfahren.

Patients with chronic kidney disease are at increased risk for cardiovascular morbidity and mortality, with the increased prevalence of supraventricular and ventricular arrhythmia being an important factor. The underlying pathomechanisms are diverse and mainly cause increasing atrial and ventricular fibrosis with so-called cardiac remodeling. In particular, patients with advanced kidney disease were excluded from many pioneering clinical trials, so there are no clear guidelines in the treatment of cardiac arrhythmia for these patients. The potential benefits of implantable cardioverter defibrillator (ICD) therapy for the prevention of sudden cardiac death or the benefits of anticoagulation for prevention of thromboembolic events in atrial fibrillation should therefore be evaluated individually for each patient with advanced kidney disease, taking comorbidities and the prognosis into account. When using antiarrhythmic drugs, a dose adjustment may be necessary depending on the pharmacokinetics and metabolism. Although atrial fibrillation treatment by means of pulmonary vein isolation can lead to an improvement in kidney function, the success rate seems to be significantly reduced in the presence of advanced kidney disease. Overall, an individual therapy and treatment concept for each patient with advanced chronic kidney disease is advisable.

[Atrial fibrillation in patients with sepsis and non-cardiac infections]. / Vorhofflimmern bei nichtkardialen Infektionen und Sepsis.

Atrial fibrillation (AF) is by far the most frequent cardiac arrhythmia associated with sepsis and infections. Newly occurring AF due to infections is associated with a deterioration of the prognosis for acute events and also for the long-term prognosis of patients. The risk of developing AF during an infection depends on general (e.g. age, structural heart disease) as well as infection-specific risk factors (e.g. sepsis severity, vasopressor treatment). Current guidelines do not make specific recommendations on the treatment of infection-associated AF and very few prospective data are available. The use of beta blockers appears to be safe for both prevention and frequency control of AF even in patients requiring catecholamines. For specific antiarrhythmic treatment, the use of class I antiarrhythmic agents is conceivable as an alternative to the predominantly used amiodarone. Newly occurring AF within infections has long been considered a specific entity with a low risk of recurrence, so that only a small proportion of patients received long-term effective anticoagulation; however, data from large retrospective studies suggest significantly higher recurrence rates. Therefore, the question of whether this group of patients benefits from long-term effective anticoagulation and extended monitoring of arrhythmia should be the subject of future research.

[Subcutaneous implantable cardioverter-defibrillator : Current status and perspectives]. / Subkutan implantierbarer Kardioverter-Defibrillator : Aktueller Stand und Ausblick.

The use of transvenous implantable cardioverter-defibrillators (ICD) for the prevention of sudden cardiac death has been proven in numerous randomized trials. By using a totally subcutaneous ICD (S-ICD) system, it is expected to ensure appropriate protection while avoiding long-term complications associated with transvenous leads, such as systemic infection and electrode dysfunction. Meanwhile, the safety and effectiveness of the S­ICD has been substantiated by results of large registry studies. Based on the missing option for ventricular stimulation, corresponding recommendations have been integrated into current guidelines for certain patient populations. In the future, the issue of inadequate shocks caused by oversensing may be solved using advanced screening tools and new detection algorithms. Furthermore, a combination of subcutaneous ICD and LCP (leadless cardiac pacer) seems realistic to enable antibradycardia and antitachycardia ventricular pacing.