Ventricular tachycardia (VT) storm after cryoballoon-based pulmonary vein isolation

Objective: Unusual clinical course. Background: Following catheter ablation of atrial fibrillation, increased incidence of ventricular arrhythmia has been observed. We report a case of sustained ventricular arrhythmia in a patient who underwent cryoballoon-based pulmonary vein isolation for symptomatic persistent atrial fibrillation. Case Report: A 57-year-old patient with dilated cardiomyopathy underwent CB-based pulmonary vein isolation for symptomatic persistent AF. On the day following an uneventful procedure, the patient for the first time experienced a sustained ventricular tachycardia that exacerbated into VT storm. Each arrhythmia was terminated by the ICD that had been implanted for primary prevention. Antiarrhythmic treatment with amiodarone was initiated immediately. The patient remained free from sustained ventricular arrhythmia during follow-up. Conclusions: After pulmonary vein isolation, physicians should be vigilant for ventricular arrhythmia. The influence of atrial autonomic innervation on ventricular electrophysiology is largely unknown

Left atrial diverticulum - An unexpected finding in routine transesophageal echocardiography

We report a 55-year-old male patient with lone paroxysmal atrial fibrillation who underwent routine transesophageal echocardiography (TOE) at our institution. In a mid-esophageal 125 degrees three-chamber angulation, a distinct thinning of the left atrial (LA) wall was observed, forming a 7 x 4 mm canal with only a small membrane separating the LA from the pericardial space. Cardiac magnetic resonance imaging diagnosed a small LA diverticulum. To the best of our knowledge, this is the first manuscript describing detection of a small LA diverticulum via TOE

Oxidative Stress and Inflammatory Modulation of Ca2+ Handling in Metabolic HFpEF-Related Left Atrial Cardiomyopathy

Metabolic syndrome-mediated heart failure with preserved ejection fraction (HFpEF) is commonly accompanied by left atrial (LA) cardiomyopathy, significantly affecting morbidity and mortality. We evaluate the role of reactive oxygen species (ROS) and intrinsic inflammation (TNF-α, IL-10) related to dysfunctional Ca2+ homeostasis of LA cardiomyocytes in a rat model of metabolic HFpEF. ZFS-1 obese rats showed features of HFpEF and atrial cardiomyopathy in vivo: increased left ventricular (LV) mass, E/e' and LA size and preserved LV ejection fraction. In vitro, LA cardiomyocytes exhibited more mitochondrial-fission (MitoTracker) and ROS-production (H2DCF). In wildtype (WT), pro-inflammatory TNF-α impaired cellular Ca2+ homeostasis, while anti-inflammatory IL-10 had no notable effect (confocal microscopy; Fluo-4). In HFpEF, TNF-α had no effect on Ca2+ homeostasis associated with decreased TNF-α receptor expression (western blot). In addition, IL-10 substantially improved Ca2+ release and reuptake, while IL-10 receptor-1 expression was unaltered. Oxidative stress in metabolic syndrome mediated LA cardiomyopathy was increased and anti-inflammatory treatment positively affected dysfunctional Ca2+ homeostasis. Our data indicates, that patients with HFpEF-related LA dysfunction might profit from IL-10 targeted therapy, which should be further explored in preclinical trials

Implantable loop recorders in patients with unexplained syncope: Clinical predictors of pacemaker implantation

Background: Implantable loop recorders (ILR) are a valuable tool for the investigation of unexplained syncopal episodes. The aim of this retrospective single center study was to identify predictive factors for pacemaker implantation in patients with unexplained syncope who underwent ILR insertion. Methods: One hundred six patients were retrospectively analyzed (mean age 59.1 years; 47.2% male) with unexplained syncope and negative conventional testing who underwent ILR implantation. The pri- mary study endpoint was detection of symptomatic or asymptomatic bradycardia requiring pacemaker implantation.  Results: The average follow-up period after ILR implantation was 20 ± 15 months. Pacemaker im- plantation according to current guidelines was necessary in 22 (20.8%) patients, mean duration until index bradycardia was 81 ± 88 (2–350) days. Ten (45.5%) patients received a pacemaker due to sinus arrest, 7 (31.8%) patients due to third-degree atrioventricular block, 2 (9.1%) patients due to second- degree atrioventricular block and 1 (4.5%) patient due to atrial fibrillation with a slow ventricular rate. Three factors remained significant in multivariate analysis: obesity, which defined by a body mass index above 30 kg/m2 (OR: 7.39, p = 0.014), a right bundle branch block (OR: 9.40, p = 0.023) and chronic renal failure as defined by a glomerular filtration rate of less than 60 mL/min (OR: 6.42, p = 0.035). Conclusions: Bradycardia is a frequent finding in patients undergoing ILR implantation due to un- explained syncope. Obesity, right bundle branch block and chronic renal failure are independent clinical predictors of pacemaker implantation

Wearable cardioverter‐defibrillator: friend or foe in suspected myocarditis?

Aim: Wearable cardioverter defibrillator (WCD, LifeVest, and Zoll) therapy has become a useful tool to bridge a temporarily increased risk for sudden cardiac death. However, despite extensive use, there is a lack of evidence whether patients with myocarditis and impaired LVEF may benefit from treatment with a WCD. Methods and results: We conducted a single-centre retrospective observational study analysing patients with a WCD prescribed between September 2015 and April 2020 at our institution. In total, 135 patients were provided with a WCD, amongst these 76 patients (mean age 48.9 +/- 13.7 years; 84.2% male) for clinically suspected myocarditis. Based on the results of the endomyocardial biopsy and, where available cardiac magnetic resonance imaging, 39 patients (51.3%) were diagnosed with myocarditis and impaired LVEF and 37 patients (48.7%) with dilated cardiomyopathy (DCM) without evidence of cardiac inflammation. The main immunohistopathological myocarditis subtype was lymphocytic myocarditis in 36 (92.3%) patients, and four patients (10.3%) of this group had an acute myocarditis. Three patients had cardiac sarcoidosis (7.7%). Ventricular tachycardia occurred in seven myocarditis (in total 41 VTs; 85.4% non-sustained) and one DCM patients (in total one non-sustained ventricular tachycardia). Calculated necessary WCD wearing time until ventricular tachycardia occurrence is 86.41 days in myocarditis compared with 6.46 years in DCM patients. Conclusions: Our data suggest that myocarditis patients may benefit from WCD therapy. However, as our study is not powered for outcome, further randomized studies powered for the outcome morbidity and mortality are necessary

Impaired Relaxation and Reduced Lusitropic Reserve in Atrial Myocardium in the Obese Patients

Background: Obesity can influence the structure and function of the atrium, but most studies focused on the relationship of body mass index (BMI) and overt left atrium (LA) dysfunction as assessed by clinical imaging. We combined the assessment of right atrium (RA) function in vivo and in vitro in obese and non-obese patients scheduled for elective cardiac surgery. Methods: Atrial structure and function were quantified pre-operatively by echocardiography. RA tissue removed for the establishment of extracorporeal support was collected and RA trabeculae function was quantified in vitro at baseline and with adrenergic stimulation (isoproterenol). Fatty acid-binding protein 3 (FABP3) was quantified in RA tissue. Results were stratified according to the BMI of the patients. Results: About 76 patients were included pre-operatively for the echocardiographic analysis. RA trabeculae function at baseline was finally quantified from 46 patients and RA function in 28 patients was also assessed with isoproterenol. There was no significant correlation between BMI and the parameters of atrial function measured by the clinical echocardiography. However, in vitro measurements revealed a significant correlation between BMI and a prolonged relaxation of the atrial myocardium at baseline, which persisted after controlling for the atrial fibrillation and diabetes by the partial correlation analysis. Acceleration of relaxation with isoproterenol was significantly lower in the obese group (BMI ≥ 30 kg/m(2)). As a result, relaxation with adrenergic stimulation in the obese group remained significantly higher compared to the overweight group (25 kg/m(2) ≤ BMI < 30 kg/m(2), p = 0.027) and normal group (18.5 kg/m(2) ≤ BMI < 25 kg/m(2), p = 0.036). There were no differences on impacts of the isoproterenol on (systolic) developed force between groups. The expression of FABP3 in the obese group was significantly higher compared to the normal group (p = 0.049) and the correlation analysis showed the significant correlations between the level of FABP3 in the RA trabeculae function. Conclusion: A higher BMI is associated with the early subclinical changes of RA myocardial function with the slowed relaxation and reduced adrenergic lusitropy

Low‐voltage shock impedance measurements: A false sense of security

Background: Implantable cardioverter defibrillators use low-voltage shock impedance measurements to monitor the lead integrity. However, previous case reports suggest that low-voltage shock impedance measurements may fail to detect insulation breaches that can cause life-threatening electrical short circuits. Methods and results: We report six cases of insulation breaches in transvenous defibrillation leads that were not obvious during standard interrogations and testing of the lead beforehand. In two cases, an electrical short circuit during commanded shock delivery for internal electrical cardioversion resulted in a total damage of the ICD generator. In one of these cases, commanded shock delivery induced ventricular fibrillation, which required external defibrillation. In two cases, a shock due to ventricular tachycardia was aborted as the shock impedance was less than 20 Ω. However, in both cases the tiny residual shock energy terminated the ventricular tachycardia. In contrast, in one case the residual energy of the aborted shock did not end ventricular fibrillation induced at defibrillator threshold testing. In one case, the ICD indicated an error code for a short circuit condition detected during an adequate shock delivery. Conclusions: This case series illustrates that low-voltage shock impedance measurements can fail to detect insulation breaches. These data suggest that in patients without a contraindication, traditional defibrillator threshold testing or high voltage synchronized shock at the time of device replacement should be considered

Quality assurance process within the RAdiosurgery for VENtricular TAchycardia (RAVENTA) trial for the fusion of electroanatomical mapping and radiotherapy planning imaging data in cardiac radioablation

A novel quality assurance process for electroanatomical mapping (EAM)-to-radiotherapy planning imaging (RTPI) target transport was assessed within the multi-center multi-platform framework of the RAdiosurgery for VENtricular TAchycardia (RAVENTA) trial. A stand-alone software (CARDIO-RT) was developed to enable platform independent registration of EAM and RTPI of the left ventricle (LV), based on pre-generated radiotherapy contours (RTC). LV-RTC were automatically segmented into the American-Heart-Association 17-segment-model and a manual 3D-3D method based on EAM 3D-geometry data and a semi-automated 2D-3D method based on EAM screenshot projections were developed. The quality of substrate transfer was evaluated in five clinical cases and the structural analyses showed substantial differences between manual target transfer and target transport using CARDIO-RT

STereotactic Arrhythmia Radioablation (STAR): the Standardized Treatment and Outcome Platform for Stereotactic Therapy Of Re-entrant tachycardia by a Multidisciplinary consortium (STOPSTORM.eu) and review of current patterns of STAR practice in Europe

The EU Horizon 2020 Framework-funded Standardized Treatment and Outcome Platform for Stereotactic Therapy Of Re-entrant tachycardia by a Multidisciplinary (STOPSTORM) consortium has been established as a large research network for investigating STereotactic Arrhythmia Radioablation (STAR) for ventricular tachycardia (VT). The aim is to provide a pooled treatment database to evaluate patterns of practice and outcomes of STAR and finally to harmonize STAR within Europe. The consortium comprises 31 clinical and research institutions. The project is divided into nine work packages (WPs): (i) observational cohort; (ii) standardization and harmonization of target delineation; (iii) harmonized prospective cohort; (iv) quality assurance (QA); (v) analysis and evaluation; (vi, ix) ethics and regulations; and (vii, viii) project coordination and dissemination. To provide a review of current clinical STAR practice in Europe, a comprehensive questionnaire was performed at project start. The STOPSTORM Institutions' experience in VT catheter ablation (83% ≥ 20 ann.) and stereotactic body radiotherapy (59% > 200 ann.) was adequate, and 84 STAR treatments were performed until project launch, while 8/22 centres already recruited VT patients in national clinical trials. The majority currently base their target definition on mapping during VT (96%) and/or pace mapping (75%), reduced voltage areas (63%), or late ventricular potentials (75%) during sinus rhythm. The majority currently apply a single-fraction dose of 25 Gy while planning techniques and dose prescription methods vary greatly. The current clinical STAR practice in the STOPSTORM consortium highlights potential areas of optimization and harmonization for substrate mapping, target delineation, motion management, dosimetry, and QA, which will be addressed in the various WPs

Research on methods to improve success rates of electrical cardioversion and catheter ablation

VHF ist die häufigste anhaltende Herzrhythmusstörung beim Menschen. Seine Behandlung stellt weiterhin eine große Herausforderung dar. Primäres Therapieziel ist die Vermeidung von durch VHF verursachten Komplikationen wie Thrombembolien oder Entwicklung einer Herzinsuffizienz. Daneben stellt die Verbesserung der Lebensqualität ein weiteres wichtiges Behandlungsziel dar. Die einem VHF zugrunde liegenden pathophysiologischen Mechanismen sind komplex und variieren von Patient zu Patient, zum Teil auch erheblich. Bei einigen Patienten spielen die PV mit ihren komplexen elektrophysiologischen, anatomischen und neuronalen Besonderheiten eine führende Rolle. Diese Patienten können mit einer PVI kurativ behandelt werden, wenn eine dauerhafte elektrische Isolation der PV gelingt. Hier-für sind Verbesserungen der Ablationstechnologien, eventuell unterstützt durch pharmakologische Maßnahmen, von zentraler Bedeutung. Katheter mit Anpress-druckmessung sowie möglicherweise eine Roboter-assistierte Steuerung des Ablationskatheters können einen Beitrag dazu leisten, dauerhafte transmurale Ablationsläsionen zu erreichen. Bei anderen Patienten spielt neben den PV das Ausmaß des strukturellen atrialen Remodelings eine wesentliche Rolle. Diese Patienten möglichst frühzeitig zu identifizieren und optimal zu behandeln ist von großer Relevanz. Der mittels Speckle-Tracking-Echokardiografie bestimmte linksatriale Strain sowie die linksatriale Strain Rate korrelieren gut mit dem Ausmaß der in der DE-MRT detektierten atrialen Fibrose und eignen sich gut für die Vorhersage des Ablationserfolgs bei VHF. Biomarker wie das MR-proADM erwiesen sich hier ebenfalls als sehr hilfreich. Darüber hinaus konnte gezeigt werden, dass auch der genetische Polymorphismus rs75114 im EPHX2-Gen mit dem Erfolg einer Katheterablation von VHF assoziiert ist. Die Rolle der EET sowie der sEH bei der Entstehung einer chronischen Ablationsläsion stellt einen interessanten Ansatz dar, der in weiteren Studien untersucht werden sollte.Atrial fibrillation (AF) is the most common sustained arrhythmia in humans. Its treatment is still challenging. Primary treatment goal is the prevention of AF related complications, such as thromboembolism or worsening of heart failure. Improvement of quality of life of patients suffering from AF is also an important treatment goal. The pathophysiology of AF is complex and varies from patient to patient. In some patients, the pulmonary veins (PV) with their specific electrophysiological, anatomical and neuronal characteristics have a dominant role. These patients may be treated curatively by pulmonary vein isolation, given that a durable electrical isolation of the PV can be achieved. Therefor improvements in ablation technology, maybe supported by pharmacological treatments are needed. Ablation catheters equipped with force sensing technology or robotic assisted ablation may help in achieving this goal. In other patients, the extent of structural atrial remodeling has a dominant role. To identify these patients early enough to initiate specific treatment is of major relevance. Left atrial strain and left atrial strain rate show a high correlation with left atrial fibrosis detected by delayed enhancement MRI and have a good prognostic value in predicting success and failure of catheter ablation of AF. Biomarkers, such as MR-proADM have also been shown to be helpful in this regard. Furthermore it could be shown, that the single nucleotid polymorphism rs 75114 in the EPHX2-gene is associated with success of AF ablation. The role of epoxyeicosatrienoic acids and soluble epoxide hydrolase in the formation of a chronic ablation lesion is an interesting topic that should be investigated in future studies