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Was ist neu? Neuerungen in der Diagnostik bei ventrikulären Arrhythmien Die Leitlinie legt einen besonderen Schwerpunkt auf praxisnahe Empfehlungen und beinhaltet u.a. übersichtliche Algorithmen. Es werden zahlreiche neue Empfehlungen zur kardialen MRT und genetischen Testung ausgesprochen. Langzeitmanagement ventrikulärer Arrhythmien Grundpfeiler des Langzeitmanagements bleibt die optimale Behandlung der Grunderkrankung. Die Leitlinie enthält Algorithmen zur antiarrhythmischen Pharmakotherapie und konkrete ICD-Programmierempfehlungen. Idiopathische ventrikuläre Arrhythmien Die Empfehlungen beziehen neben der Symptomatik auch die VES-Last mit ein. Die Katheterablation wird Erstlinientherapie bei idiopathischen ventrikulären Arrhythmien aus dem rechtsventrikulären Ausflusstrakt und linken Faszikel sowie bei VES-aggravierter oder -induzierter Kardiomyopathie. Koronare Herzerkrankung Die aktuellen Empfehlungen zur primärprophylaktischen ICD-Therapie beziehen die programmierte elektrische Stimulation zur Risikostratifizierung ein. Die Ergebnisse der VANISH-Studie modifizieren die Empfehlungen zur Katheterablation bei rezidivierenden VT. Dilatative Kardiomyopathie Neben der linksventrikulären Funktion werden in den Empfehlungen zur primärprophylaktischen ICD-Therapie auch bildmorphologische, genetische und klinische Faktoren berücksichtigt. Primär elektrische Erkrankungen Für eine Vielzahl primär elektrischer Erkrankungen werden dezidierte Diagnosekriterien formuliert. Neu sind zahlreiche Empfehlungen zur genetischen Diagnostik.

Aims The incidence of in-hospital post-interventional complications and mortality after ablation of supraventricular tachycardia (SVT) vary among the type of procedure and most likely the experience of the centre. As ablation therapy of SVT is progressively being established as first-line therapy, further assessment of post-procedural complication rates is crucial for health care quality. Methods and results We aimed at determining the incidence of in-hospital mortality and bleeding complications from SVT ablations in German high-volume electrophysiological centres between 2005 and 2020. All cases were registered by the German Diagnosis Related Groups—and the German Operation and Procedure Classification (OPS) system. A uniform search for SVT ablations from 2005 to 2020 with the same OPS codes defining the type of ablation/arrhythmia as well as the presence of a vascular complication, cardiac tamponade, and/or in-hospital death was performed. An overall of 47 610 ablations with 10 037 SVT ablations were registered from 2005 to 2020 among three high-volume centres. An overall complication rate of 0.5% (n = 38) was found [median age, 64; ±15 years; female n = 26 (68%)]. All-cause mortality was 0.02% (n = 2) and both patients had major prior co-morbidities precipitating a lethal outcome irrespective of the ablation procedure. Vascular complications occurred in 10 patients (0.1%), and cardiac tamponade was detected in 26 cases (0.3%). Conclusion The present case-based analysis shows an overall low incidence of in-hospital complications after SVT ablation highlighting the overall very good safety profile of SVT ablations in high-volume centres. Further prospective analysis is still warranted to guarantee continuous quality control and optimal patient care.

Introduction: Hormone-mediated therapies are on the rise and are key therapies in the treatment of some of the most common cancer entities. Proarrhythmic effects have been described in patients treated with SERMs while little to none is known about the electrophysiological effects of the potentially less arrhythmogenic selective estrogen receptor degraders. Methods: Twenty hearts of female New Zealand White rabbits were excised and retrogradely perfused employing a Langendorff setup. An electrophysiology study was performed to obtain CL-dependent action potential duration at 90% of repolarization (APD90), QT interval, effective refractory period (ERP), and post-repolarization refractoriness (PRR = ERP-APD90). After generating baseline data, the hearts were assigned to two groups and perfused with (n = 10) increasing doses of fulvestrant (1 µM and 5 µM; n = 10) or tamoxifen (2.5 µM and 7.5 µM; n = 10), and the protocol was repeated again. Results: Fulvestrant led to a decrease in APD90 and QT interval and an increased PRR. The inducibility of ventricular tachycardia (VT) episodes was unaltered. Tamoxifen showed similar effects, resulting in a shortened APD90 and QT interval and no increased VT incidence in the setting of a prolonged PRR. Conclusion: The present study shows no acute proarrhythmic effect of tamoxifen and fulvestrant in an established whole heart model when employing clinically relevant concentrations.

Purpose The present study validated a software-based electrocardiogram (ECG) analysis tool for detection of atrial fibrillation (AF) and risk for AF using polysomnography (PSG)-derived ECG recordings. Methods The Stroke Risk Analysis® (SRA®) software was applied to 3-channel ECG tracings from diagnostic PSG performed in enrolled subjects including a subgroup of subjects with previously documented AF. No subjects used positive airway pressure therapy. All ECG recordings were visually analyzed by a blinded cardiologist. Results Of subjects enrolled in the study, 93 had previously documented AF and 178 of 186 had an ECG that could be analyzed by either method. In subjects with known history of AF, automated analysis using SRA® classified 47 out of 87 ECG as either manifest AF or showing increased risk for paroxysmal AF (PAF) by SRA® (sensitivity 0.54, specificity 0.86). On visual analysis, 36/87 ECG showed manifest AF and 51/87 showed sinus rhythm. Among the latter subgroup, an increased risk for PAF was ascribed by SRA® in 11 cases (sensitivity 0.22, specificity 0.78) and by expert visual analysis in 5 cases (sensitivity 0.1, specificity 0.90). Among 36/178 ECG with manifest AF on visual analysis, 33 were correctly identified by the SRA® software (sensitivity and specificity 0.92). Conclusion Sleep studies provide a valuable source of ECG recordings that can be easily subjected to software-based analysis in order to identify manifest AF and automatically assess the risk of PAF. For optimal evaluability of data, multiple channel ECG tracings are desirable. For assessment of PAF risk, the SRA® analysis probably excels visual analysis, but sensitivity of both methods is low, reflecting that repeated ECG recording remains essential.

BACKGROUND Previous studies have raised serious concerns on cardiovascular safety of widely prescribed nonsteroidal anti-inflammatory drugs (NSAIDs). Therefore, the aim of this study was to characterize the electrophysiological effects of certain NSAIDs in an established whole heart model of proarrhythmia. METHODS AND RESULTS Thirty-eight hearts of New Zealand White rabbits were harvested and retrogradely perfused employing a Langendorff setup, and electrophysiology studies were performed to investigate action potential duration at 90% of repolarization (APD90 ), QT intervals, and effective refractory period (ERP). After generating baseline data, hearts were perfused with ibuprofen (Group 1, n = 12; 10 and 30 μM), indomethacin (Group 2, n = 13; 10 and 20 μM) and diclofenac (Group 3, n = 13; 10 and 20 μM), respectively, and the pacing protocols were repeated for each concentration. In all groups, perfusion with the NSAIDs resulted in a significant and reproducible shortening of APD90 and QT interval. In all groups, the arrhythmia susceptibility was significantly raised as occurrence of monomorphic ventricular tachycardia under programmed ventricular stimulation was significantly increased under perfusion with ibuprofen, indomethacin and diclofenac in all concentrations. CONCLUSION The perfusion with ibuprofen, indomethacin and diclofenac in commonly used doses raised the arrhythmia susceptibility in an established rabbit whole-heart model while APD shortening and shortened ERP seem to be crucial for arrhythmogenesis.

The recently published guidelines of the European Society of Cardiology (ESC) on the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death is an update of the 2015 guideline. For the first time a new section is dedicated to public basic life support. In the acute treatment of ventricular arrhythmias electrical cardioversion is upgraded, and there is a new focus on the management of electrical storm. Recommendations for the comprehensive diagnostic evaluation of patients with first manifestations of ventricular arrhythmias structured according to common clinical scenarios are also new. Both genetic testing and cardiac magnetic resonance imaging are upgraded, not only for diagnostic evaluation but also for risk stratification. In the long-term management, recommendations for pharmacotherapy are aligned with current heart failure guidelines. Catheter ablation has gained relevance not only for recurrent ventricular tachycardia under amiodarone treatment and as an alternative to implantable cardioverter defibrillation (ICD) implantation in selected patients with coronary artery disease but also particularly in the treatment of idiopathic ventricular extrasystoles and tachycardia. The ICD treatment remains an essential component of primary and secondary prevention of sudden cardiac death. Of note, the recommendation on primary preventive ICD treatment for patients with dilated cardiomyopathy and left ventricular ejection fraction (LVEF) ≤ 35% has been downgraded. In addition to LVEF a combination of risk factors and risk calculators is included in the recommendations on primary prophylactic ICD implantation. Overall, due to numerous tables and practical algorithms, the guidelines have become a user-oriented reference book.Die vor Kurzem veröffentlichte Leitlinie der European Society of Cardiology (ESC) für das Management von Patienten mit ventrikulären Arrhythmien (VA) und zur Prävention des plötzlichen Herztodes aktualisiert die Leitlinie aus dem Jahr 2015. Erstmals wird die Laienreanimation Leitlinienthema. In der Akuttherapie von VA wird die Elektrokardioversion aufgewertet, zudem liegt ein neuer Fokus auf dem Management des elektrischen Sturms. Neu ist die Gliederung der Empfehlungen zur umfassenden Diagnostik von Patienten mit Erstmanifestation von VA anhand häufiger klinischer Szenarien. Sowohl die genetische Diagnostik als auch die kardiale Magnetresonanztomographie werden aufgewertet, nicht nur für die Diagnostik, sondern auch zur Risikostratifikation. In der Langzeittherapie werden Empfehlungen zur Pharmakotherapie an aktuelle Herzinsuffizienzleitlinien angeglichen. Die Katheterablation gewinnt nicht nur bei rezidivierenden ventrikulären Tachykardien unter Amiodarontherapie und als Alternative zur Implantation eines implantierbaren Kardioverter-Defibrillators (ICD) bei ausgewählten Patienten mit koronarer Herzkrankheit, sondern insbesondere bei der Behandlung idiopathischer ventrikulärer Extrasystolen und Tachykardien an Bedeutung. Die ICD-Therapie bleibt essenzieller Bestandteil der Primär- und Sekundärprävention des plötzlichen Herztodes. Bemerkenswert ist hier die Abwertung der ICD-Empfehlung für Patienten mit dilatativer Kardiomyopathie und linksventrikulärer Ejektionsfraktion (LVEF) von ≤35 %sowie die Einbeziehung einer Kombination von Risikofaktoren und -kalkulatoren neben der LVEF in die Empfehlungen zur primärprophylaktischen ICD-Implantation. Durch zahlreiche Übersichtstabellen und Algorithmen ist die Leitlinie insgesamt zu einem praxisnahen Nachschlagewerk geworden.

The aim of this study is to evaluate retinal and optic nerve head (ONH) perfusion in patients with systolic chronic heart failure (CHF) compared to healthy control subjects. Twenty-seven eyes of 27 patients with CHF (study group) and 31 eyes of 31 healthy subjects (control group) were prospectively included in this study. CHF Patients had a left ventricular ejection fraction (LVEF)

Aims The present study aims at analyzing the role of a preimplantation 12-lead electrocardiogram (ECG) on the prediction of inappropriate S-ICD® episodes. Methods N=116 screened patients (pts) with an S-ICD® and a follow-up of at least 6 months were included. A preimplantation 12-lead ECG (50 mm/s, 10 mm/mV) was analyzed with regard to QRS and T-wave amplitude, T wave concordance or discordance and QRS/T wave ratio in all 12 leads. To ensure an exact determination of parameters Datinf® Measure software was used. Results were correlated to the occurrence of oversensing of cardiac signals during follow-up. Results N = 116 pts. (63,8% male, mean age 40,9 ± 15,5 years) were included (primary prevention in 47.4% of pts). The most frequent cardiac diseases were hypertrophic cardiomyopathy (HCM) in n = 25 (21,6%), electrical heart disease in n = 20 (17,2%), and dilated cardiomyopathy in n = 17 (14,7%). Mean follow-up was 740 ± 549 days. During follow- up n = 17 (14.7%) pts. experienced n = 27 inappropriate episodes due to T-wave oversensing. Besides HCM (OR 6.16, CI 1.79–21.15, p = 0.004) a discordance of QRS to T-wave in lead I (OR 6.5, CI 1.86–22.67, p = 0.003) was found to be a strong predictor for inappropriate shocks. In multivariate analysis the pts. with a combination of both had an 8.4-fold higher risk of misclassification of intracardiac signals (p = 0.003) with consecutive inappropriate therapy. Conclusion A discordance of QRS to T-wave in lead I turned out to be a strong predictor for future inappropriate shocks in a typical S-ICD® cohort with special impact on HCM pts.

1. Introduction: Pulmonary vein isolation (PVI) is an established procedure used to achieve rhythm control in atrial fibrillation (AF). In obese patients (pts), in whom AF occurs more frequently, a reduced effectiveness of PVI has been observed. Therefore, this study’s aim was to compare the long-term efficacy of PVI between obese and non-obese patients. 2. Methods: We enrolled 111 consecutive pts with a body mass index (BMI) of >30 kg/m2 undergoing PVI from our large registry. Procedural data and outcomes were compared with a matched group of 115 non-obese PVI pts and the long-term outcomes were analyzed. 3. Results: Overall follow-up duration was 314 patient-years in the obese and 378 patient-years in the non-obese group. The follow-up rate was 71% in the obese and 76% in the non-obese group. In both groups, their AF-characteristics did not differ significantly, while known risk factors were significantly more prevalent in the obese group. Procedural characteristics were similar in both groups. During follow-up, the obese pts demonstrated significant weight loss compared to the non-obese pts, while at the same time, the overall recurrence rate during follow-up did not differ significantly between both groups (obese: 39.2% and non-obese: 43.7%). PVI related and long-term complications were comparable between both groups. In the univariate analysis, obesity was not found to be associated with an increased AF recurrence risk. 4. Conclusion: These real-life data demonstrate that obese pts may not show higher AF recurrence rates after PVI compared to pts with normal body weight. Furthermore, PVI was found to be safe and effective in obese patients; thus, a BMI alone may not be a criterion for refusal of PVI.

Introduction: The long-QT syndrome (LQTS) is the most common ion channelopathy, typically presenting with a prolonged QT interval and clinical symptoms such as syncope or sudden cardiac death. Patients may present with a concealed phenotype making the diagnosis challenging. Correctly diagnosing at-risk patients is pivotal to starting early preventive treatment. Objective: Identification of congenital and often concealed LQTS by utilizing novel deep learning network architectures, which are specifically designed for multichannel time series and therefore particularly suitable for ECG data. Design and Results: A retrospective artificial intelligence (AI)-based analysis was performed using a 12-lead ECG of genetically confirmed LQTS (n = 124), including 41 patients with a concealed LQTS (33%), and validated against a control cohort (n = 161 of patients) without known LQTS or without QT-prolonging drug treatment but any other cardiovascular disease. The performance of a fully convolutional network (FCN) used in prior studies was compared with a different, novel convolutional neural network model (XceptionTime). We found that the XceptionTime model was able to achieve a higher balanced accuracy score (91.8%) than the associated FCN metric (83.6%), indicating improved prediction possibilities of novel AI architectures. The predictive accuracy prevailed independently of age and QTc parameters. Conclusions: In this study, the XceptionTime model outperformed the FCN model for LQTS patients with even better results than in prior studies. Even when a patient cohort with cardiovascular comorbidities is used. AI-based ECG analysis is a promising step for correct LQTS patient identification, especially if common diagnostic measures might be misleading.

The long-QT syndrome (LQTS) is the most common ion channelopathy, typically presenting with a prolonged QT interval and clinical symptoms such as syncope or sudden cardiac death. Patients may present with a concealed phenotype making the diagnosis challenging. Correctly diagnosing at-risk patients is pivotal to starting early preventive treatment.Identification of congenital and often concealed LQTS by utilizing novel deep learning network architectures, which are specifically designed for multichannel time series and therefore particularly suitable for ECG data.A retrospective artificial intelligence (AI)-based analysis was performed using a 12-lead ECG of genetically confirmed LQTS (In this study, the XceptionTime model outperformed the FCN model for LQTS patients with even better results than in prior studies. Even when a patient cohort with cardiovascular comorbidities is used. AI-based ECG analysis is a promising step for correct LQTS patient identification, especially if common diagnostic measures might be misleading.

Catheter-based ablation is nowadays a safe and widespread procedure for the treatment of cardiac arrhythmia. This requires exact anatomical knowledge both before and during the examination and is an important prerequisite for targeted treatment. At the beginning of the era of interventional catheter-based treatment, fluoroscopy was the only and usual means of visualization, whereas in the middle of the 1990s continuous 3D-mapping systems were developed for the non-fluoroscopic examination of patients. The correct use of these 3‑D systems, which non-fluoroscopically visualize the catheter and mostly identify mechanisms of arrhythmia in great detail, nowadays makes an important contribution to successful interventional catheter treatment of arrhythmia; however, it is not uncommon for patients with ventricular arrhythmia to also carry implanted electronic devices, such as pacemakers, defibrillators or less frequently left ventricular hemodynamic support systems. All implantable devices lead to electromagnetic interferences, which can complicate the diagnostics and treatment during electrophysiological examinations and ablation. This article addresses the adversities and experiences associated with magnet-based 3D systems and implantable electromagnetically active cardiac devices.Katheterablationen sind heute ein weit verbreitetes Verfahren zur Behandlung von Herzrhythmusstörungen. Hierfür sind genaue anatomische Kenntnisse sowohl im Vorfeld als auch während der Untersuchung erforderlich und eine wichtige Voraussetzung zur zielgerichteten Behandlung. Während zu Beginn der Ära von katheterinterventionellen Behandlungen die Fluoroskopie das einzige und gängige Visualisierungsmittel war, sind seit Mitte der 1990er Jahre kontinuierlich 3‑D-Mappingssysteme zur nichtfluoroskopischen Untersuchung von Patienten (weiter)entwickelt worden. Die sachgemäße Anwendung dieser 3‑D-Systeme, die Katheter nichtfluoroskopisch visualisieren und Arrhythmiemechanismen meist sehr detailliert identifizieren, leistet heute einen bedeutsamen Beitrag zur erfolgreichen katheterinterventionellen Behandlung von Rhythmusstörungen. Vor allem Patienten mit ventrikulären Arrhythmien sind jedoch nicht selten Träger elektronischer Devices wie Defibrillatoren oder teilweise hämodynamischen Unterstützungssystemen. Implantierbare Devices führen zu elektromagnetischen Interferenzen, die die Diagnostik und Behandlung im Rahmen elektrophysiologischen Untersuchungen und Ablationen erschweren können. Dieser Artikel diskutiert die Widrigkeiten und Erfahrungen in Zusammenhang mit magnetbasierten 3‑D-Systemen sowie implantierbaren elektromagnetisch aktiven „cardiac devices“.

Decision-making in primary prevention is not always trivial and many clinical scenarios are not reflected in current guidelines. To help evaluate a patient's individual risk, a new score to predict the benefit of an implantable defibrillator (ICD) for primary prevention, the MADIT-ICD benefit score, has recently been proposed. The score tries to predict occurrence of ventricular arrhythmias and non-arrhythmic death based on data from four previous MADIT trials. We aimed at examining its usefulness in a large single-center register of S-ICD patients with various underlying cardiomyopathies.All S-ICD patients with a primary preventive indication for ICD implantation from our large single-center database were included in the analysis (The MADIT-ICD benefit score adds a new option to evaluate expected benefit of ICD implantation for primary prevention. In a large S-ICD cohort of primary prevention, the value of the score was limited to patients with ischemic cardiomyopathy. Future research should evaluate the performance of the score in different subgroups and compare it to other risk scores to assess its value for daily clinical practice.

Introduction Supraventricular tachycardias (SVT) are often difficult to document due to their intermittent, short-lasting nature. Smartphone-based one-lead ECG monitors (sECG) were initially developed for the diagnosis of atrial fibrillation. No data have been published regarding their potential role in differentiating inappropiate sinus tachycardia (IST) from regular SVT. If cardiologists could distinguish IST from SVT in sECG, economic health care burden might be significantly reduced. Methods We prospectively recruited 75 consecutive patients with known SVT undergoing an EP study. In all patients, four ECG were recorded: a sECG during SVT and during sinus tachycardia and respective 12-lead ECG. Two experienced electrophysiologists were blinded to the diagnoses and separately evaluated all ECG. Results Three hundred individual ECG were recorded in 75 patients (47 female, age 50 ± 18 years, BMI 26 ± 5 kg/m2, 60 AVNRT, 15 AVRT). The electrophysiologists’ blinded interpretation of sECG recordings showed a sensitivity of 89% and a specificity of 91% for the detection of SVT (interobserver agreement κ = 0.76). In high-quality sECG recordings (68%), sensitivity rose to 95% with a specificity of 92% (interobserver agreement of κ = 0.91). Specificity increased to 96% when both electrophysiologists agreed on the diagnosis. Respective 12-lead ECG had a sensitivity of 100% and specificity of 98% for the detection of SVT. Conclusion A smartphone-based one-lead ECG monitor allows for differentiation of SVT from IST in about 90% of cases. These results should encourage cardiologists to integrate wearables into clinical practice, possibly reducing time to definitive diagnosis of an arrhythmia and unnecessary EP procedures. Graphical abstract A smartphone-based one lead ECG device (panel A) can be used reliably to differentiate supraventricular tachycardia (panel B) from inappropriate sinus tachycardia when compared to a simultaneously conducted gold-standard electrophysiology study (panels C, D).

Sarcoidosis is a multisystem granulomatous disease of unknown etiology characterized by noncaseating granulomas. Cardiac involvement is often limiting patients' prognosis. Cardiac sarcoidosis can manifest with variant cardiac arrhythmias, of which atrioventricular (AV)-block-related bradycardia and ventricular tachycardias are the most common. Although cardiac sarcoidosis remains a histopathological diagnosis, the significance of imaging modalities, especially cardiac magnetic resonance imaging is increasing rapidly but mainly remains reserved for patients with a high suspicion due to a previous arrhythmia or unknown cardiomyopathy. Thus, there is a need for screening in daily clinical practice so that possible characteristic electrocardiographic (ECG) findings may guide the way to detect the disease. We therefore evaluated the ECG as a potential tool for screening of cardiac sarcoidosis and present different electrophysiological manifestations of cardiac sarcoidosis based on a literature review. The ECG is a valuable tool for screening of cardiac involvement in patients with sarcoidosis. Several parameters have been shown to be associated with cardiac involvement in sarcoidosis such as higher-degree AV-block, QRS complex fragmentation and widening, as well as certain T wave abnormalities that may indicate cardiac involvement, of which the latter two are most promising and specific. However, prospective studies examining a large number of trials are desirable.

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common regular supraventricular tachycardia (SVT). Slow pathway modification (SPM) is the accepted first line treatment with reported success rates around 95%. Information regarding possible predictors of AVNRT recurrence is scarce.Out of 4170 consecutive patients with SPM in our department from 1993-2018, we identified 78 patients (1.9%) receiving > 1 SPM (69% female, median age 50 years) with a recurrence of AVNRT after a successful SPM. We matched these patients for age, gender and number of radiofrequency applications during first SPM with 78 patients who received one successful SPM in our center without AVNRT recurrence. Both groups were analyzed for possible predictors of a recurrence of AVNRT during long-term follow-up. The recurrence group contained a significantly lower proportion of patients with an occurrence of junctional beats during SPM (69% versus 89%, P = 0.006). Moreover, significantly more cases of previously diagnosed atrial fibrillation/tachycardia (AF/AT; 21% versus 5%, P = 0.007) and inducible AF/AT during electrophysiology study (23% versus 6%, P = 0.006) were present in the recurrence group. While more than half of patients had a recurrence within the first year, in 20% symptoms reappeared ≥ 4 years after ablation.In a small percentage of patients, AVNRT recurs after an initially successful ablation. Interestingly, these patients had significantly fewer junctional beats during ablation and a higher rate of other (inducible) arrhythmias. AVNRT recurrence spanned a considerable timeframe and should remain a differential diagnosis, even years after ablation.

Background The benefits of de novo cardiac resynchronization therapy (CRT) in patients with QRS-prolongation and impaired left-ventricular function (LVEF) are well established. Current guidelines also recommend CRT-upgrade in patients requiring permanent or frequent right ventricular pacing (RVP) with symptomatic heart failure and reduced LVEF. Whereas several predictors of response to de novo CRT-implantation such as female gender, QRS-duration, non-ischemic cardiomyopathy (NICM) are known due to large prospective trials, similar factors regarding CRT-upgrade are currently lacking. Methods and results We examine 114 patients 3–6 months after CRT-upgrade due to frequent RVP (> 50%) and symptomatic heart failure. Response to CRT was evaluated by improvement in NYHA class referring to the Minnesota Living With Heart Failure Questionnaire. Only cardiomyopathy type and use of Angiotensin-converting-enzyme (ACE) inhibitor had an impact on response to CRT-upgrade in a linear regression model. Patients with NICM presented a greater responder rate than patients with ischemic cardiomyopathy (ICM) (80.4 vs. 60.3%, p Conclusion Only underlying heart disease (NICM vs. ICM) and the use of ACE inhibitor were significant predictors of response to CRT-upgrade. In contrast to de novo CRT-recipients, where pre-implant QRS-duration is a key predictor, QRS-duration during RV-pacing has no significant impact on CRT-response in this cohort. Graphic abstract

Introduction: Transesophageal echocardiography (TEE) is routinely performed before catheter ablation of atrial tachyarrhythmias to rule out the presence of left atrial thrombi. However, data to support this practice are inconsistent. Methods: We analyzed consecutive pre-procedural TEE in a high-volume electrophysiology center for the presence of left atrial thrombi and a relevant flow reduction in the left atrial appendage (LAA) defined as LAA sludge or LAA emptying velocity (LAAEV) < 20 cm/s. The possible predictors of reduced flow were recorded and compared in a multivariate logistic regression analysis. Results: 1676 TEE were included (1122 before pulmonary vein isolation, 436 before atrial flutter ablation, 166 before other ablations). 543 patients (32%) were female and 991 (59%) were on DOAC. Nine patients (0.5%) had an LAA thrombus on pre-procedural TEE. Ninety-five further patients (5.7%) had a relevant reduction in LAA flow. The underlying rhythm showed a significant association with the presence of LAA thrombus or reduced LAA flow (p = 0.003). Patients in sinus rhythm and cavotricuspid isthmus-dependent atrial flutter exhibited the lowest risk. Additionally, reduced kidney function was associated with a reduction in LAA flow velocities (p = 0.04). Of note, two LAA thrombi occurred in patients in sinus rhythm and six out of nine patients with an LAA thrombus were on vitamin-K antagonists. Conclusions: LAA thrombus is a rare occurrence before an elective catheter ablation. The underlying rhythm and kidney function may serve as markers of a higher likelihood of significantly reduced LAAEV and LAA thrombus.

Aim The subcutaneous ICD (S-ICD) has evolved to a potential first option for many patients who have to be protected from sudden cardiac death. Many trials have underlined a similar performance regarding its effectiveness in relation to transvenous ICDs and have shown the expected benefits concerning infective endocarditis and lead failure. However, there have also been problems due to the peculiarities of the device, such as oversensing and myopotentials. In this study, we present patients from a large tertiary centre suffering from complications with an S-ICD and propose possible solutions. Methods and results All S-ICD patients who experienced complications related to the device (n = 40) of our large-scale single-centre S-ICD registry (n = 351 patients) were included in this study. Baseline characteristics, complications occurring and solutions to these problems were documented over a mean follow-up of 50 months. In most cases (n = 23), patients suffered from oversensing (18 cases with T wave or P wave oversensing, 5 due to myopotentials). Re-programming successfully prevented further oversensing episode in 13/23 patients. In 9 patients, generator or lead-related complications, mostly due to infectious reasons (5/9), occurred. Further problems consisted of ineffective shocks in one patient and need for antibradycardia stimulation in 2 patients and indication for CRT in 2 other patients. In total, the S-ICD had to be extracted in 10 patients. 7 of them received a tv-ICD subsequently, 3 patients refused re-implantation of any ICD. One other patient kept the ICD but had antitachycardic therapy deactivated due to inappropriate shocks for myopotential oversensing. Conclusion The S-ICD is a valuable option for many patients for the prevention of sudden cardiac death. Nonetheless, certain problems are immanent to the S-ICD (limited re-programming options, size of the generator) and should be addressed in future generations of the S-ICD. Graphic abstract

Several case reports suggest QT prolongation leading to ventricular arrhythmias with fatal outcome after intoxication with the μ-opioid receptor agonist and anti-diarrheal agent loperamide. The number of cases of loperamide misuse are growing due to its potential stimulating effects. Loperamide intoxications can be treated by naloxone. However, previous reports described a further QT prolongation associated with naloxone administration. Therefore, the aim of this study was to investigate the effects of loperamide and naloxone on the cardiac electrophysiology in a sensitive whole-heart model. Twenty-six hearts of New Zealand White rabbits were retrogradely perfused in a modified Langendorff apparatus. Monophasic action potentials were recorded by endo- and epicardially positioned catheters. Hearts were stimulated at different cycle lengths, thereby obtaining action potential duration at 90% of repolarization (APD90) and QT intervals. Programmed ventricular stimulation was used to assess ventricular vulnerability. Fourteen hearts were perfused with ascending concentrations of loperamide (0.2 μM, 0.35 μM, and 0.5 μM) after obtaining baseline data. Another 12 hearts were treated with naloxone (0.1 μM, 0.5 μM, 2 μM). Loperamide led to a significant increase in QT interval, APD90, and ventricular tachycardia (VT) episodes. In contrast, naloxone led to a decrease in QT interval and APD90. Accordingly, the number of VT episodes was unaltered. To the best of our knowledge, this is the first experimental study that investigated the effects of loperamide and naloxone in a whole-heart model. Loperamide led to a significant increase in action potential duration and QT interval. Simultaneously, the number of ventricular tachycardias was significantly increased. In contrast, naloxone led to a shortening of the action potential duration without altering arrhythmia susceptibility.

Introduction: Periprocedural oral anticoagulation (OAC) strategies for atrial fibrillation (AF) ablation procedures are changing rapidly. Objective: To assess the management and course of periprocedural OAC for AF ablation procedures in experienced electrophysiology (EP) centers in Germany over the last 12 months. Methods: The data are based on an electronic questionnaire, which was sent to 35 experienced EP centers in September 2018 and then exactly 1 year later. Participants provided information on their periprocedural OAC management, the handling with dual therapy (OAC plus single antiplatelet therapy), the availability of specific antidotes, the transseptal puncture approach, and noteworthy complications. Results: Responses were received from all 35 centers and represent 10,010 AF ablation procedures annually. In 2018, the administration of vitamin K antagonist (VKA) was continued throughout the procedure at all centers (100%). In contrast, the majority of centers used minimally interrupted periprocedural non-vitamin K antagonist oral anticoagulants (NOAC) (54.3%), 13 centers (37.2%) completely interrupted NOAC, and only 3 centers (8.5%) continued NOAC throughout the procedure. At the 1-year follow-up survey, 32 centers were found to have continued their previous strategy of periprocedural OAC and 3 changed from a minimally interrupted to a continued NOAC strategy. Of note, 30 centers (85.7%) performed transseptal puncture fluoroscopically without additional cardiac imaging. In the setting of uninterrupted periprocedural OAC management, no relevant complications were noted. Conclusion: Our survey shows marked heterogeneous periprocedural OAC management at experienced EP centers in Germany. Whereas continuation of VKA has already been integrated into clinical practice, the majority of centers still use a minimally interrupted NOAC strategy.

Background The right bundle branch block (RBBB) and the bifascicular blocks affect QRS duration in the right precordial leads, which are usually used for QT interval determination. Up to now, there is no clear recommendation how to determine QT interval in patients with RBBB or bifascicular block. Hypothesis The hypothesis of the present study was to evaluate the feasibility of a simple formula for RBBB and bifascicular block correction, thereby making it easier to determine the QTc interval. Methods In patients with intrinsic QRS duration

Background The subcutaneous implantable-cardioverter defibrillator (S-ICD™, Boston Scientific, Natick, MA, USA) is an important advance in device therapy for the prevention of sudden cardiac death (SCD). Although current guidelines recommend S-ICD™ use, long-term data are still limited, especially in subgroups. Dilated cardiomyopathy (DCM) is a common reason for the implantation of an ICD. However, there are no sufficient data on the performance of the S-ICD™ in this patient cohort. Materials and methods All S-ICD™ patients with DCM as the main indication for ICD implantation (n = 47 patients) in our large-scaled single-center S-ICD™ registry (n = 294 patients) were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 22.9 ± 18.5 months. Results A total of 47 patients with DCM as the underlying structural heart disease received an S-ICD™ in our institution. Mean left ventricular ejection fraction was 37 ± 12% and a 28% had a history of ventricular tachyarrhythmia. During follow-up eight ventricular tachyarrhythmias were adequately terminated in three patients. In four patients, oversensing resulting in an inappropriate shock was observed, which could be managed by changing the sensing vector. There was no need for a change to a cardiac resynchronization (CRT) system while one system was changed to a VVI-ICD due to S-ICD™ wound infection. Conclusion The S-ICD™ seems to be a valuable option for the prevention of SCD in patients with DCM and no indication for CRT. As clinically relevant ventricular arrhythmias consisted of ventricular fibrillation or fast ventricular tachycardia in all patients in our cohort, no change to transvenous ICDs for anti-tachycardia pacing delivery was necessary.

As with all cardiac interventions, performing left ventricular ablation requires profound knowledge of cardiac anatomy. The aim of this article is to provide an overview of left ventricular anatomy and to characterize complex and clinically relevant structures from an electrophysiologist-centered perspective. In addition to the different access routes, the trabecular network, the left ventricular outflow tract, and the left ventricular conduction system, complex anatomical structures such as the aortomitral continuity and the left ventricular summit are also explained. In addition, this article offers multiple clinical examples that combine ECG, anatomy, and electrophysiologic study.Die Durchführung einer linksventrikulären Ablation setzt, wie bei grundsätzlich allen kardialen Interventionen, eine gute Kenntnis der kardialen Anatomie voraus. Ziel dieses Artikels ist es, eine Übersicht über die Anatomie des linken Ventrikels zu geben und komplexe klinisch relevante Strukturen aus einer untersucherzentrierten Perspektive zu charakterisieren. Neben den unterschiedlichen Zugangswegen, dem Trabekelwerk, dem linksventrikulären Ausflusstrakt und dem spezifischen Reizleitungssystem, sollen im Folgenden auch komplexe anatomische Strukturen wie die aortomitrale Kontinuität und der linksventrikuläre Summit erläutert und kartiert werden. Darüber hinaus bietet dieser Artikel mehrere klinische Fälle, die eine Verbindung zwischen EKG, Anatomie und Ablation ermöglichen sollen.

Background: Left atrial tachycardias (LAT) are a well-known outcome of pulmonary vein isolation (PVI). Few data are available on whether the catheter used to perform PVI influences the incidence, as well as the characteristics of post PVI LAT. We present data on LAT following PVI by the following three ablation technologies: (1) phased multi-electrode radiofrequency catheter (PVAC), (2) irrigated single-tip catheter (iRF), and (3) cryoballoon ablation. Methods: Using a prospectively designed single-center database, we analyzed 650 patients (300 iRF, 150 PVAC, and 200 cryoballoon) with paroxysmal (n = 401) and persistent atrial fibrillation (AF), who underwent their first PVI at our center. Results: The three populations were comparable in their baseline characteristics; however, the cryoballoon group comprised a higher percentage of patients with persistent AF (p = 0.05). The LAT rates were 3.7% in the iRF group (mean follow-up 22 ± 14 months), 0.7% in the PVAC group (mean follow-up 21 ± 14 months), and 4% in the cryoballoon group (mean follow-up 15 ± 8 months). The predominant mechanism of LAT was macro-reentrant tachycardia. Reconnection of at least one pulmonary vein was observed in 87% of the patients who underwent 3D mapping. No predictors for LAT occurrence were identified. Conclusion: The occurrence of LAT post PVI is rare; the predominant mechanism was macro-reentrant tachycardia. Reconnection of at least one pulmonary vein was observed in nearly all the LAT patients. In our retrospective analysis, the lowest rate of LAT was observed with the PVAC. No predictors for LAT occurrence were identified.

Several case reports have suggested an increased risk of sudden cardiac death due to energy drinks. Therefore, the purpose of this study was to assess acute electrophysiologic effects of caffeine and taurine, two of the main ingredients of energy drinks, in an experimental whole-heart model.Twenty-five rabbit hearts were excised, retrogradely perfused, and assigned to two groups. Hearts were perfused with caffeine (2, 10, and 50 µM) or taurine (2, 10, and 50 µM) after generating baseline data. Eight monophasic action potentials and electrocardiography recordings showed a significant abbreviation of action potential duration (APDIn this experimental whole-heart study, treatment with caffeine and taurine provoked ventricular arrhythmias. The underlying mechanism was an abbreviation of cardiac repolarizations and effective refractory periods that may facilitate re-entry and thereby provokes arrhythmias. These findings help to understand the potentially hazardous and fatal outcomes after intoxication with energy drinks.

The current AF definition requires recording in classical ECG or Holter ECG at least a 30-s episode of AF. According to the current definition, the presence of frequent shorter episodes of fast atrial arrhythmia or episodes of arrhythmia identified with widely used screening tools requires subsequent steps to establish a definite diagnosis of AF. The use of different clinical risk scores can help to refine target populations better. Due to the unpredictable and highly variable nature of AF episodes, a monitoring time lasting 2 weeks or longer is preferable to maximize the possibility of identifying subjects with AF. Several capabilities are currently available for AF search/screening, including devices based on plethysmographic pulse assessment, belts and vests for long-term ECG monitoring, modern Holter capabilities, and ILRs. Decision-making regarding using particular of them should depend on proof of efficacy based on published data, patient characteristics, and purpose of monitoring (screening/search). Additionally, all subjects with CIED with the possibility of atrial sensing should be carefully evaluated to identify AHREs. In large-scale screening projects, ML and AI could provide the appropriate interpretation of large databases containing the results of a giant number of participants. From the patient perspective, participation in screening has positive but also negative aspects. Therefore, each patient should be able to accept or refuse to participate in a screening programme, being fully aware of the potential benefits or hurdles of the screening. As the first step of shared decision-making, identifying a patient’s values, goals, and preferences is mandatory.

In patients with high risk for sudden cardiac death the implantation of a defibrillator is an established treatment. However the benefits and risks for patients in accordance to the number of the leads are not clear. Even in the current guidelines a recommendation to this question is missing. We analyzed advantage and disadvantages of single-chamber implantable cardioverter defibrillators (VVI-ICD) versus dual-chamber implantable cardioverter defibrillators (DDD-ICD) in the prospective German Device Registry. The data of 2240 patients who underwent ICD implantation in 45 German Centers between January 2007 and March 2011 were included in a prospective device registry (VVI: n = 1629, male = 1358, EF = 34% ± 13%; DDD: n = 611, male = 491, EF = 35% ± 14%). The in-hospital complications were significantly higher in the DDD-ICD group with higher revision/device complication rates (3.0% vs. 1.2%; p = 0.003) but also higher mortality rate (1.0% vs. 0.1%; p

Purpose: To evaluate retinal and optic nerve head (ONH) perfusion in patients with atrial fibrillation (AF) before and after catheter ablation of AF with pulmonary vein isolation (PVI). Methods: 34 eyes of 34 patients with AF and 35 eyes of 35 healthy subjects were included in this study. Flow density data were obtained using spectral-domain OCT-A (RTVue XR Avanti with AngioVue, Optovue, Inc, Fremont, California, USA). The data of the superficial and deep vascular layers of the macula and the ONH (radial peripapillary capillary network, RPC) before and after PVI were extracted and analysed. Results: The flow density in the superficial OCT-angiogram (whole en face) and the ONH (RPC) in patients with AF was significantly lower compared to healthy controls (OCT-A superficial: study group: 48.77 (45.19; 52.12)%; control group: 53.01 (50.00; 54.25)%; p < 0.001; ONH: study group: 51.82 (48.41; 54.03)%; control group: 56.00 (54.35; 57.70)%; p < 0.001;). The flow density in the ONH (RPC) improved significantly in the study group following PVI (before: 51.82 (48.41; 54.03)%; after: 52.49 (50.34; 55.62)%; p = 0.007). Conclusions: Patients with AF showed altered ocular perfusion as measured using OCTA when compared with healthy controls. Rhythm control using PVI significantly improved ocular perfusion as measured using OCT-A. Non-contact imaging using OCTA provides novel information about the central global microperfusion of patients with AF.

Aims: Thromboembolic events, including stroke, are typical complications of COVID-19. Whether arrhythmias, frequently described in severe COVID-19, are disease-specific and thus promote strokes is unclear. We investigated the occurrence of arrhythmias and stroke during rhythm monitoring in critically ill patients with COVID-19, compared with severe pneumonia of other origins.Methods and Results: This retrospective study included 120 critically ill patients requiring mechanical ventilation in three European tertiary hospitals, including n =60 COVID-19, matched according to risk factors for the occurrence of arrhythmias in n = 60 patients from a retrospective consecutive cohort of severe pneumonia of other origins. Arrhythmias, mainly atrial fibrillation (AF), were frequent in COVID-19. However, when compared with non-COVID-19, no difference was observed with respect to ventricular tachycardias (VT) and relevant bradyarrhythmias (VT 10.0 vs. 8.4 %, p = ns and asystole 5.0 vs. 3.3%, p = ns) with consequent similar rates of cardiopulmonary resuscitation (6.7 vs. 10.0%, p = ns). AF was even more common in non-COVID-19 (AF 18.3 vs. 43.3%, p = 0.003; newly onset AF 10.0 vs. 30.0%, p = 0.006), which resulted in a higher need for electrical cardioversion (6.7 vs. 20.0%, p = 0.029). Despite these findings and comparable rates of therapeutic anticoagulation (TAC), the incidence of stroke was higher in COVID-19 (6.7.% vs. 0.0, p = 0.042). These events also happened in the absence of AF (50%) and with TAC (50%).Conclusions: Arrhythmias were common in severe COVID-19, consisting mainly of AF, yet less frequent than in matched pneumonia of other origins. A contrasting higher incidence of stroke independent of arrhythmias also observed with TAC, seems to be an arrhythmia-unrelated disease-specific feature of COVID-19.

Background: Different electrocardiogram (ECG) findings are known to be independent predictors of clinical response to cardiac resynchronization therapy (CRT). It remains unknown how these findings influence very long-term prognosis. Methods and Results: A total of 102 consecutive patients (75 males, mean age 65 ± 10 years) referred to our center for CRT implantation had previously been included in this prospective observational study. The same patient group was now re-evaluated for death from all causes over a prolonged median follow-up of 10.3 years (interquartile range 9.4–12.5 years). During follow-up, 55 patients died, and 82% of the clinical non-responders (n = 23) and 44% of the responders (n = 79) were deceased. We screened for univariate associations and found QRS width during biventricular (BIV) pacing (p = 0.02), left ventricular (LV) pacing (p &lt, 0.01), Δ LV paced–right ventricular (RV) paced (p = 0.03), age (p = 0.03), New York Heart Association (NYHA) class (p &lt, 0.01), CHA2DS2-Vasc score (p &lt, 0.01), glomerular filtration rate (p &lt, 0.01), coronary artery disease (p &lt, 0.01), non-ischemic cardiomyopathy (NICM) (p = 0.01), arterial hypertension (p &lt, 0.01), NT-proBNP (p &lt, 0.01), and clinical response to CRT (p &lt, 0.01) to be significantly associated with mortality. In the multivariate analysis, NICM, the lower NYHA class, and smaller QRS width during BIV pacing were independent predictors of better outcomes. Conclusion: Our data show that QRS width duration during biventricular pacing, an ECG parameter easily obtainable during LV lead placement, is an independent predictor of mortality in a long-term follow-up. Our data add further evidence that NICM and lower NYHA class are independent predictors for better outcome after CRT implantation.

Recent versions of evidence-based guidelines on the management of atrial fibrillation (AF) have been published by the European Society of Cardiology (ESC) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS), the American College of Cardiology, American Heart Association, and the Heart Rhythm Society (AHA/ACC/HRS), and the Canadian Cardiovascular Society/Canadian Heart Rhythm Society (CCS). As all societies refer to the same multicentric and usually multinational studies, the similarities undoubtedly outweigh the differences. Nonetheless, interesting differences can often be found in details, which are usually based on a different assessment of the same study, the availability of data in relation to the publication date and local preferences and availabilities of certain cardiovascular drugs. The following article aims at lining out these similarities and differences.

Introduction: Multiple studies have shown that left atrial (LA) enlargement is a strong predictor of poor outcome after catheter ablation of atrial fibrillation (AF). LA size is commonly approximated as the diameter in the parasternal long axis. It remains unknown whether more precise echocardiographic measurements of LA size allow for better correlation with outcome after pulmonary vein isolation (PVI). Methods and results: We performed a retrospective study of 131 consecutive patients (43 females, 60% paroxysmal AF, mean CHA2DS2-Vasc score 1.6, mean age 61 ± 12 years) referred for PVI. Measurements of the LA were carried out by a single observer in transthoracic echocardiograms (TTE) performed prior to ablation. We calculated diameter of the LA in the parasternal long axis (PLAX), LA area in the 2- as well as 4-Chamber (CH) view. LA volume was computed using the disc summation technique (LAV) and indexed to body surface area (LAVI). Procedural and follow-up data were gathered from a prospective AF database. Ablation was performed exclusively using the second generation cryoballoon by the same operators. Follow-up visits at 3, 6 and 12 months showed freedom from AF in 76%, 73% and 73% respectively. Mean values of LA calculations were LAPLAX: 37.9 mm ± 6.3 mm, 2CH area: 22.5 cm2 ± 6.7 cm2, 4CH area: 21.4 cm2 ± 5.5 cm2, LAV: 73.7 mL ± 26.1 mL and LAVI: 36.2 mL/m2 ± 12.7 mL/m2, respectively. C statistic revealed the best concordance of LAVI with outcome after 12 months (C = 0.67), LAV also exhibited a satisfactory value (C = 0.61) in comparison to surfaces in 2CH (C = 0.59) and 4CH (C = 0.57). PLAX showed the worst correlation (C = 0.51). Additionally, different binary logistic regression models identified three independent predictors of AF outcome after cryoballoon PVI: gender (OR = 0.95 per year, p = 0.01), LAV (OR = 1.3/10mL, p = 0.02) and LAVI (OR = 1.58/10 mL/m2, p = 0.02). In all models, PLAX and area measurements were not predictive. Conclusions: Our data add further to evidence that LA size lends itself well as a predictor of PVI outcome. LAVI and LAV were independently predictive of rhythm outcome after PVI. This did not hold true for more commonly used measurements, such as PLAX diameter and surfaces of the LA, irrespective of the view chosen.

Background: The subcutaneous ICD (S-ICD) is used in an increasing number of patients for primary and secondary prevention of sudden cardiac death. Decision-making in primary prevention is not always trivial and many clinical scenarios are not reflected in current ICD guidelines. To help evaluating the patient’s individual risk, a new score trying to predict the benefit of an ICD implantation for primary prevention, the MADIT-ICD benefit score, which tries to predict occurrence of ventricular arrhythmias and non-arrhythmic death, has been proposed. We therefore aimed at examining its usefulness in a large single centre register of S-ICD patients Methods and results: All S-ICD patients with a primary preventive indication for ICD implantation from our large single centre database were included in the analysis (n=173). During a follow-up of 1227±978 days 27 patients developed sustained ventricular arrhythmias, while 6 patients died for non-arrhythmic reasons. Occurrence of ventricular arrhythmias could not sufficiently be predicted by the MADIT-ICD VT/VF score (p=0.3) in patients with (n=142, p=0.19) as well as patients without structural heart disease (n=31, p=0.88). However, there was a significant correlation for patients with ischemic cardiomyopathy (ICM) (n=29, p=0.04). Only one parameter (non-sustained ventricular tachycardia) was significantly associated with sustained ventricular arrhythmias (p=0.02). Of note, non-arrhythmic death could effectively be predicted by the proposed non-arrhythmic mortality score as part of the benefit score (p=0.001, r=0.3) also mainly driven by ICM patients. Age, diabetes mellitus, and a BMI 2 were key predictors of non-arrhythmic death implemented in the score.Conclusion: The MADIT-ICD benefit score adds a new option to evaluate expected benefit of ICD implantation for primary prevention. However, in our S-ICD cohort, the only group in which the score worked properly for prediction of sudden and non-sudden death were ICM patients, so that a larger validation in more heterogeneous cohorts in mandatory to claim general validity for this score in risk stratification for primary preventive ICD implantation.

Atrial fibrillation and other atrial tachyarrhythmias are increasing with age and concomitant morbidity. First options in symptomatic patients are drug treatment and catheter ablation. Nevertheless, a considerable number of patients suffer from refractory atrial tachyarrhythmias despite treatment. Atrioventricular node ablation (AVNA) may be helpful in many of these patients. Therefore, we investigated AVNA patients with a long-term follow-up. We enrolled 82 patients with a follow-up longer than 1 year receiving AVNA for drug- and ablation-resistant atrial tachyarrhythmias (AA) in a retrospective manner. Mean follow-up duration was 48 ± 24 months. 50% of the patients initially received AVNA to optimize biventricular pacing in cardiac resynchronization therapy, the other 50% because of refractory symptomatic tachyarrhythmias. Persistent AV block was achieved in every patient. Symptom relief and patient satisfaction were high during follow-up. Due to system upgrades there were 63% of patients with a biventricular system during follow-up. In these patients, left-ventricular ejection fraction (LV-EF) increased by 7% (42-49%) after ablation. AVNA is effective in increasing biventricular pacing as well as for symptom relief in patients with refractory atrial tachyarrhythmias. AVNA should be considered as a valuable option in patients with refractory atrial tachyarrhythmias lacking other treatment options.

The subcutaneous ICD (S-ICD™) is an important advance in device therapy for the prevention of sudden cardiac death (SCD). Although current guidelines recommend S-ICD™ use, long-term data are still limited, especially in subgroups. Among several cardiac diseases that prone to SCD, coronary artery disease (CAD) carries several peculiarities that may hamper S-ICD™ therapy in this cohort. CAD can lead to an ischemic cardiomyopathy (ICM) with a reduced left-ventricular ejection fraction (LVEF) and bundle branch blocks, which can be difficult for ICD sensing and discrimination of arrhythmia. CAD is mainly driven by risk factors such as diabetes mellitus, which put these patients at an elevated risk for infectious complications of cardiac devices. Furthermore, in ICM myocardial scars are frequent and are a potential substrate for ventricular tachycardia, which may be accessible for antitachycardia pacing. At the moment, it remains unclear if there is a value of S-ICD™ therapy in this subgroup. Therefore, this study analysed patients with CAD. All S-ICD™ patients with CAD as the main indication for ICD implantation (n = 45 patients) in our large-scaled single-center S-ICD™ registry (n = 249 patients) were included in this study. Baseline characteristics, appropriate and inappropriate shocks, and complications were documented in a mean follow-up of 22.5 ± 8.3 months. Primary prevention of SCD was the indication for implantation of an S-ICD™ in 28 patients (62%). Of all 45 patients with an overall mean age of 58.1 ± 11.4 years, 40 were male (88%). The mean LVEF was 37.7 ± 12.6%. Three episodes of ventricular arrhythmia (one monomorphic, one polymorphic, one ventricular fibrillation) were adequately terminated in three patients (7%). In only one patient, oversensing resulting in an inappropriate shock was observed, which could be managed by changing the sensing vector. 15 of the examined 45 patients previously had a transvenous ICD, which was explanted due to system-related infections. In only two patients, S-ICD™ was changed to transvenous ICD because of the need of antibradycardia stimulation. There were no S-ICD™ system-related infections. The S-ICD™ seems to be a valuable option for the prevention of SCD in CAD patients. Patients with systemic infections of a transvenous ICD and, therefore, a need for an alternative might benefit from the absence of intracardiac leads as the S-ICD™ is safe and works flawlessly in these patients. Inadequate shock delivery was very rare, while every episode of ventricular arrhythmia was terminated by the first shock.

A post hoc analysis of the PALLAS trial suggested life-threatening interactions of digitalis and dronedarone. Thus, there is concern about an interplay between digitalis and other drugs that influence cardiac electrophysiology. We therefore investigated the interaction between digitalis and flecainide or ranolazine. Twenty-five rabbit hearts were Langendorff-perfused and treated with flecainide (2 µM, 12 hearts) or ranolazine (10 µM, 13 hearts). Infusion of flecainide prolonged mean action potential duration [APD90, from 153 ms (interquartile range (IQR): 29.7 ms) to 159 ms (IQR: 24.9 ms, p = 0.04)] and effective refractory period [ERP, 170 ms (IQR: 40 ms) vs. 200 ms (IQR: 32.5 ms, p

Background Metoclopramide (MCP) is a dopamine D2 -receptor antagonist, mainly used to treat post-operative or chemotherapy-induced nausea. While it is very effective in the cure of gastric symptoms, MCP can cause severe neurologic side effects. Furthermore, there is growing evidence for severe arrhythmic side effects resulting from inhibitory effects on cardiac sodium and potassium channels. Methods and results Thirteen hearts of New Zealand white rabbits were retrogradely perfused, and electrophysiology studies were performed to obtain action potential duration (APD90 ) and effective refractory period (ERP). After generating baseline data, the hearts were perfused with increasing concentrations of metoclopramide (MCP 10 µM, MCP 50 µM, MCP 100 µM) and the standardized protocol was repeated for each concentration. Perfusion with MCP resulted in a significant prolongation of APD90 and QT interval. In parallel, the incidence of ventricular tachycardias was significantly increased by high doses of MCP. Conclusion This is the first experimental study that investigated the effect of increasing doses of metoclopramide on a sensitive whole-heart model of proarrhythmia. MCP led to a significant increase in action potential duration and QT interval; meanwhile, the number of ventricular tachycardias was significantly increased.

Atrioventricular nodal reentry tachycardia (AVNRT) is the most common regular supraventricular tachycardia (SVT). Slow pathway modification (SPM) is the accepted first line treatment with reported success rates around 95%. Information regarding possible predictors of AVNRT recurrence is scarce.Out of 4170 consecutive patients with SPM in our department from 1993-2018, we identified 78 patients (1.9%) receiving1 SPM (69% female, median age 50 years) with a recurrence of AVNRT after a successful SPM. We matched these patients for age, gender and number of radiofrequency applications during first SPM with 78 patients who received one successful SPM in our center without AVNRT recurrence. Both groups were analyzed for possible predictors of a recurrence of AVNRT during long-term follow-up. The recurrence group contained a significantly lower proportion of patients with an occurrence of junctional beats during SPM (69% versus 89%, P = 0.006). Moreover, significantly more cases of previously diagnosed atrial fibrillation/tachycardia (AF/AT; 21% versus 5%, P = 0.007) and inducible AF/AT during electrophysiology study (23% versus 6%, P = 0.006) were present in the recurrence group. While more than half of patients had a recurrence within the first year, in 20% symptoms reappeared ≥ 4 years after ablation.In a small percentage of patients, AVNRT recurs after an initially successful ablation. Interestingly, these patients had significantly fewer junctional beats during ablation and a higher rate of other (inducible) arrhythmias. AVNRT recurrence spanned a considerable timeframe and should remain a differential diagnosis, even years after ablation.

The aim of this study is to evaluate retinal and optic nerve head (ONH) perfusion in patients with systolic chronic heart failure (CHF) compared to healthy control subjects.Twenty-seven eyes of 27 patients with CHF (study group) and 31 eyes of 31 healthy subjects (control group) were prospectively included in this study. CHF Patients had a left ventricular ejection fraction (LVEF) 50% and were classified by New York Heart Association (NYHA) class. OCT-A was performed using RTVue XR Avanti with AngioVue (Optovue, Inc, Fremont, CA, USA). The area of the foveal avascular zone (FAZ) and flow density (FD) data were extracted and analyzed.There was no significant difference in the signal strength index between the study group (group 1) and the control group (group 2) (ONH: p = 0.015; macula: p = 0.703). The difference in the area of the foveal avascular zone between the two groups was also not significant (p = 0.726). The flow density (whole en face) in the ONH (RPC) in group 1 was significantly lower compared to control (group 1 = 48.40 ± 2.48 (49.0 [46.7, 50.3]); group 2 = 50.15 ± 1.85 (50.6 [48.5, 51.70]); p = 0.008). There was a significant and strong correlation between LVEF and the macular flow density (whole en face) (superficial: rs = 0.605 deep: rs = 0.425, p 0.01).Patients with CHF showed reduced flow density compared with healthy controls. The reduced FD correlated with the LVEF and the functional (NYHA) class. Retinal perfusion as measured using OCTA might provide an insight into the global microperfusion and hemodynamic state of heart failure patients.

Background Previous studies report conflicting data regarding anti- or proarrhythmic effects of sacubitril. The aim of the presents study was to assess the impact of sacubitril in different arrhythmia models. Methods and results In 12 isolated rabbit hearts, sacubitril was infused in rising concentrations (3, 5, 10μM) after obtaining baseline data. In 12 further hearts, erythromycin was administered to simulate long QT syndrome-2 (LQT2). Other 12 hearts were perfused with veratridine to mimic long QT syndrome-3 (LQT3). Both LQT groups were treated with sacubitril (5μM). Ventricular vulnerability was assessed by a pacing protocol. AV-blocked bradycardic hearts were perfused with a hypokalemic solution to trigger torsade de pointes (TdP). In further 13 hearts, AF was induced by a combination of acetylcholine and isoproterenol (ACH/ISO) and sacubitril (5μM) was added afterwards. With sacubitril, action potential duration (APD) was abbreviated whereas spatial dispersion of repolarization (SDR) remained stable. In both LQT groups, APD and SDR were increased. Infusion of sacubitril reduced APD and SDR in the LQT2-group (APD: −21 ms, p Conclusion Sacubitril abbreviated APD and was not proarrhythmic. SDR is a major pathomechanism of TdP and was reduced by sacubitril in both LQT groups. Thereby, sacubitril exhibits antiarrhythmic effects in LQT2 and may be beneficial in LQT3. Furthermore, sacubitril suppressed AF by prolonging aERP. Our results indicate beneficial effects of sacubitril on cardiac electrophysiology. Funding Acknowledgement Type of funding source: None

Background Implantable cardioverter-defibrillator (ICD) systems are established for the prevention of sudden cardiac death. Long-term data on ICD function in children and adolescents is rare and has suggested higher rates of lead failure as well as oversensing, both leading to inappropriate therapy. The present study displays a long-term single-center follow-up of young patients having received an S-ICD. Methods and results The present study represents a single-center experience of patients younger than 25 years who received an S-ICD (n=49). Follow-up data included regular in-house follow-up as well as unscheduled hospitalisations in our center. Mean age at implantation was 19.2±4.1 years and 33 patients (67.4%) were male. In 21 patients (42.9%) electrical heart disease or idiopathic ventricular fibrillation represented the underlying condition of ICD implantation. 15 patients suffered from HCM (30.6%). Median follow-up duration was 2 years. No patient died during the observation period. Appropriate shocks occurred in 7 patients (14.3%). Inappropriate shock delivery was recorded in 6 patients (12.3%). T-wave oversensing was the main cause for inappropriate shock delivery (5/6 patients), in the other patient myopotentials were the reason for inappropriate therapy. In one patient, operative refixation of the subcutaneous lead was necessary due to hypermobility leading to oversensing. After modification of the sensing vector as well as activation of the SMART pass filter no further oversensing episodes occurred in any patient. Conclusion ICD therapy in children and adolescents is effective for prevention of sudden cardiac death. Every episode was terminated by the first therapy. The rate of appropriate shock as well as inappropriate therapies was quite high compared to typical ICD cohorts. In particular T-wave oversensing seems to be challenging for the S-ICD detection algorithms also in this cohort. Funding Acknowledgement Type of funding source: None

Background Dexmedetomidine is increasingly employed for conscious sedation during electrophysiological procedures. Recent experimental data have suggested direct effects of dexmedetomidine on cardiac electrophysiology. The aim of the present study was to assess the effects of dexmedetomidin on drug-induced QT-prolongation. Methods and results In 12 isolated rabbit hearts the macrolide antibiotic erythromycin (300μM) was infused as a potent Ikr blocker after obtaining baseline data. Eight endo- and epicardial monophasic action potentials and a simultaneously recorded 12-lead ECG showed a significant prolongation of QT-interval (+25ms, p Lowering of potassium concentration in bradycardic AV-blocked hearts resulted in the occurrence of early afterdepolarizations (EAD) and drug induced proarrhythmia with torsade de pointes in 6 of 12 erythromycin-treated hearts (40 episodes). Additional infusion of dexmedetomidine reduced the occurrence of torsade de pointes (4 of 12 hearts, 9 episodes). Conclusion Infusion of dexmedetomidine resulted in a reduction of spatial dispersion of repolarization in the presence of a prolonged repolarization period. This resulted in a reduction of torsade de pointes with dexmedetomidine. Furthermore, an increase of ventricular refractory periods reduced inducibility of ventricular arrhythmias. Thus, in an experimental setting dexmedetomidine shows significant antiarrhythmic effects, which may influence electrophysiologic findings during clinical electrophysiologic studies. This needs to be studied in the clinical setting. Funding Acknowledgement Type of funding source: None

Proper measurement of the QT interval on the 12-lead body-surface ECG is challenging in daily practice. Even more difficult is its correct estimation in the presence of repolarization abnormalities, arrhythmias or bundle-branch blocks (BBB). The QT interval results from two parts of the ECG: (1) the QRS complex, describing the excitation of the ventricles and (2) the JT interval, describing the repolarisation of the ventricles. Prolongation of the QRS width - like in the presence of BBB - entails prolongation of the QT interval, making the estimation of the true repolarisation time challenging. The US recommendations for the standardization and interpretation of the ECG suggest focusing on the JT interval in presence of BBB. However, in clinical practice physicians have become more familiar with the interpretation of QT-interval measurements than with the interpretation of the JT Interval. In the last decade, a simple formula for the estimation of the "modified QT interval" in the presence of left or right BBB has been developed and evaluated. In this formula, the modified QT interval is calculated by subtracting 50% of the length of the BBB-QRS from the measured QT interval (QT(m) = QT(BBB) - 50% QRS(BBB)). Subsequently, rate-correction formula should be applied as usual. In this review, we discuss the determination of the QT-interval in the presence of BBB and summarize the origin and application of the modified QT-interval formula. (C) 2020 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).