Local anesthetics are widely used in medical care. However, their sodium channel blocking properties not only explain their analgesic potency but also their possible cardiotoxic effects. Due to the different pharmacodynamics and pharmacokinetics of different local anesthetics as well as the divergent cellular electrophysiological effects, we aimed to investigate and compare the electrophysiological effects of different local anesthetics in an established Langendorff model of the isolated rabbit heart. 50 hearts of New Zealand White rabbits were retrogradely perfused employing a Langendorff-setup. Eight catheters were placed endo- and epicardially, thereby recording monophasic action potentials. Hearts were paced at seven different cycle lengths (300–900 ms), thus obtaining cycle-length dependent action potential duration at 90

Mitral valve prolapse (MVP) is commonly benign, but an arrhythmic phenotype (AMVP) with increased risk for sudden cardiac death has been described. A prolonged Tpeak-Tend interval has been association with increased arrhythmic risk in different clinical settings. The aim of this study was to investigate a possible correlation between prolonged Tpeak-Tend interval and ventricular tachycardia (VT) inducibility in MVP. Sixty-five patients fulfilling the EHRA criteria of AMVP syndrome underwent programmed ventricular stimulation between 2016 and 2024. Sustained polymorphic VT was induced in 19 patients (29.2

Mitral valve prolapse (MVP) is commonly benign, but an arrhythmic phenotype (AMVP) with increased risk for sudden cardiac death has been described. Current risk stratification is mainly based on clinical data and imaging markers, while the role of programmed ventricular stimulation (PVS) remains uncertain. In this prospective single-center cohort study, 42 patients fulfilling the EHRA consensus criteria for AMVP underwent an electrophysiological study with programmed ventricular stimulation between 2016 and 2025. Stimulation was performed from the right ventricular apex and outflow tract using up to two extra stimuli. Following shared decision-making, patients received either an implantable cardioverter-defibrillator (ICD) or an implantable loop recorder (ILR). The endpoint was the occurrence of clinically significant ventricular arrhythmias (VAs), defined as appropriate ICD therapies, ILR-documented sustained VT, or arrhythmic syncope. Sustained ventricular arrhythmias were inducible in 20 patients (47.6

BACKGROUND:With approximately 1.6 million people affected in Germany, atrial fibrillation (AF) is the most common arrhythmia. The management of AF, from prevention to treatment, including anticoagulation, is therefore of major clinical importance in terms of these patients' quality of life and their mortality. METHODS:This first German clinical practice guideline on AF was developed in accordance with the Regelwerk Leitlinien (rules for guidelines) of the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizi - nischen Fachgesellschaften e. V., AWMF). The available evidence on all relevant issues was retrieved by a systematic literature search and evaluated with the participation of many medical specialty societies. RESULTS:AF is classified on clinical grounds as paroxysmal, persis - tent, longstanding persistent, or permanent. It is associated with a 1.5- to 2-fold increase in mortality and a 4- to 5-fold increase in the risk of stroke. Nonetheless, general screening for AF is not currently recommended, as the data on this question are conflicting. Lifestyle interventions and the reduction of risk factors lessen the frequency of AF. Female sex is only a minor risk factor; the CHA2DS2-VA-Score is recommended to assess the risk of thromboembolic events. If it is 2 or higher, oral anticoagulation (OAC) is indicated, of a type that should be decided on an individual basis. In patients with cardiovascular risk factors, early rhythm control has been shown to reduce prognostically relevant cardio - vascular endpoints (3.9 versus 5.0 per 100 patientyears). Multiple studies have shown that catheter ablation is superior to drug-based antiarrhythmic therapy in patients with paroxysmal symptomatic AF as well as in those with heart failure and AF. CONCLUSION:It is hoped that the recommendations contained in this guideline will lead to intensified measures for the prevention of AF, resulting in a lower prevalence of AF and its adverse sequelae. The available evidence supports the evaluation of the indications for OAC, early rhythm control, and the use of catheter ablation, especially in patients with paroxysmal AF or heart failure.

Background: Takotsubo syndrome (TTS) is an acute cardiac condition characterized by transient left ventricular dysfunction. Although generally considered reversible, early arrhythmias are a dreaded complication and their prognostic significance remains incompletely understood. Methods: In this study, 104 consecutive patients diagnosed with TTS (January 2007 to September 2024) were examined for the prognostic relevance of in-hospital arrhythmias during monitoring at the time of diagnosis. The median follow-up was 2.1 years. The primary combined endpoint included cardiac death, TTS recurrence, occurrence of arrhythmias, and rehospitalization for cardiac causes. Results: In-hospital arrhythmias occurred in 35.6% of the patients. Ventricular arrhythmias were significantly associated with an increased risk of adverse cardiac events (odds ratio 3.94, 95% confidence interval 1.22–12.69; p = 0.021). Reduced left ventricular ejection fraction and QTc prolongation, while frequently observed, were not independently associated with adverse outcomes when analyzed separately from arrhythmic events. Supraventricular arrhythmias exhibited a non-significant trend (p = 0.145). Conclusions: In a large registry of consecutive TTS patients, in-hospital ventricular arrhythmias at diagnosis were significantly associated with adverse outcomes, underscoring the importance of early rhythm monitoring.

[This corrects the article DOI: 10.3389/fcvm.2024.1369250.].

Electrical cardioversion represents a cornerstone of rhythm control strategies in patients with atrial fibrillation. However, in patients with obesity and specific anatomical variations, e.g. post heart transplantation, the standard flow of this procedure may need to be altered. This includes employing technical deviations of shock delivery and paying special attention to potential, unexpected complications. In light of the current position paper of the German Cardiac Society (Deutsche Gesellschaft für Kardiologie, DGK) on electrical cardioversion of atrial fibrillation, two cases with unconventional course of elective electrical cardioversion of atrial fibrillation are presented: dual direct current cardioversion in severe obesity and the occurrence of ventricular fibrillation in the presence of heterotopic heart transplant.

Background: Quantum computing (QC) has emerged as an innovative technology to enhance machine learning through quantum mechanical properties such as superposition, entanglement, and projection into high-dimensional complex Hilbert spaces. These properties can improve the representational capacity and generalization of deep learning models. We explore the feasibility and efficacy of integrating quantum technology into convolutional neural networks (CNN) for echocardiographic analysis of real world data covering the spectum of congenital heart disease (CHD). Methods: We developed a hybrid deep learning algorithm incorporating a quantum computing (QC) layer within a ResNet-50 convolutional neural network. The QC layer included 4 qubits, with angle embedding and strongly entangling layers for quantum processing. Two supervised classification tasks were evaluated: (1) diagnosis classification and (2) echocardiographic view classification using a challenging dataset of echocardiographic images from patients with congenital and structural heart disease. The model was benchmarked against a conventional state-of-the art CNN model. Training/inference were conducted on high-performance classical GPUs and the QC layer were simulated and applied directly to an IBM 127-qubit Eagle r3 quantum processor (Sherbrooke, Canada). Results: Models were trained and tested on echocardiographic data derived from 262 patients and 62 controls. Diagnoses included tetralogy of Fallot (n=30), TGA (n=48), Ebstein anomaly (n=18), and other CHD/structural anomalies. A total of 9,793 loops including 284,250 frames were used for training and testing.The hybrid QC-model demonstrated superior performance in both tasks relative to the classical baseline, with improvements in accuracy, F1-score, precision, and recall. Per-class metrics showed enhanced differentiation in diagnostically challenging categories (Test accuracy 72.1% vs. 68.4% for diagnosis and 78.9 vs. 76.6% for view classification for QC vs. conventional CNN, respectively). Conclusion: This study is first to establish the applicability of quantum-computing deep learning in the field of congenital cardiology. The enhanced ability of quantum layers to map complex image data into higher-dimensional spaces offers promising advantages for AI applications, particularly in populations with high anatomic variability such as CHD.The findings pave the way for future quantum applications in precision medicine specifically benefiting CHD.

Background: Previous studies suggest a direct effect of sacubitril on cardiac electrophysiology and indicate potential arrhythmic interactions between sacubitril and antiarrhythmic drugs. Therefore, the aim of this study was to explore the electrophysiologic effects of combining sacubitril with the antiarrhythmic drugs d,l-sotalol and mexiletine in isolated hearts. Methods and results: A total of 25 rabbit hearts were perfused using a Langendorff setup. Following baseline data collection, hearts were treated with mexiletine (25 µM, 13 hearts) or d,l-sotalol (100 µM, 12 hearts). Monophasic action potential demonstrated an abbreviation of action potential duration (APD90) after administration of mexiletine. Spatial dispersion of repolarization remained unchanged after mexiletine treatment, whereas effective refractory periods (ERP) were significantly prolonged. D,l-sotalol prolonged cardiac repolarization and amplified spatial dispersion. Further infusion of sacubitril (5 µM) led to a significant reduction in APD90 and ERP in the mexiletine group. In the d,l-sotalol group, additional administration of sacubitril shortened cardiac repolarization duration without affecting spatial dispersion. No proarrhythmic effect was observed after mexiletine treatment as assessed by a predefined pacing protocol. Additional sacubitril treatment did not increase ventricular vulnerability. When potassium concentration was reduced, 30 episodes of torsade de pointes tachycardia occurred after d,l-sotalol treatment. Additional sacubitril treatment significantly suppressed torsade de pointes tachycardia (eight episodes) in the d,l-sotalol-group. Conclusions: In class IB- and class III-pretreated hearts, sacubitril shortened refractory periods and cardiac repolarization duration. The combination of sacubitril with the antiarrhythmic drugs d,l-sotalol and mexiletine demonstrates a safe electrophysiologic profile and sacubitril reduces the occurrence of class III-related proarrhythmia, i.e., torsade de pointes tachycardia.

Background: With approximately 1.6 million people affected in Germany, atrial fibrillation (AF) is the most common arrhythmia. The management of AF, from prevention to treatment, including anticoagulation, is therefore of major clinical importance in terms of these patients' quality of life and their mortality. Methods: This first German clinical practice guideline on AF was developed in accordance with the Regelwerk Leitlinien (rules for guidelines) of the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizi-nischen Fachgesellschaften e. V., AWMF). The available evidence on all relevant issues was retrieved by a systematic literature search and evaluated with the participation of many medical specialty societies. Results: AF is classified on clinical grounds as paroxysmal, persis-tent, longstanding persistent, or permanent. It is associated with a 1.5-to 2-fold increase in mortality and a 4-to 5-fold increase in the risk of stroke. Nonetheless, general screening for AF is not currently recommended, as the data on this question are conflicting. Lifestyle interventions and the reduction of risk factors lessen the frequency of AF. Female sex is only a minor risk factor; the CHA2DS2-VA-Score is recommended to assess the risk of thromboembolic events. If it is 2 or higher, oral anticoagulation (OAC) is indicated, of a type that should be decided on an individual basis. In patients with cardiovascular risk factors, early rhythm control has been shown to reduce prognostically relevant cardio-vascular endpoints (3.9 versus 5.0 per 100 patient-years). Multiple studies have shown that catheter ablation is superior to drug-based antiarrhythmic therapy in patients with paroxysmal symptomatic AF as well as in those with heart failure and AF. Conclusion: It is hoped that the recommendations contained in this guideline will lead to intensified measures for the prevention of AF, resulting in a lower prevalence of AF and its adverse sequelae. The available evidence supports the evaluation of the indications for OAC, early rhythm control, and the use of catheter ablation, especially in patients with paroxysmal AF or heart failure.

BACKGROUND:In about 8% of survivors of sudden cardiac death, no structural or electrical heart disease can be identified. Some of these patients with idiopathic ventricular fibrillation (IVF) present ECG markers of early repolarization (Early Repolarization Syndrome, ERS). The Tpeak-Tend interval has been linked to increased arrhythmic risk in different clinical settings, such as Brugada syndrome or hypertrophic cardiomyopathy. As there is limited data about the relationship of Tpeak-Tend and arrhythmogenesis in IVF, respectively, its significance in risk stratification in ERS, the aim of this study was to investigate a possible correlation between sustained ventricular arrhythmia (VA) recurrences in these patients and the Tpeak-Tend interval. METHODS AND RESULTS:We retrospectively investigated 56 consecutive IVF patients (64.3% male, mean age 37.8 ± 12.9 years) who received an implantable cardioverter-defibrillator for secondary prevention. Markers of early repolarization were present in 32.1% of cases. During a mean follow-up of 41.2 ± 35.8 months, 11 patients (19.6%) received in total 18 adequate ICD-therapies. Patients with VA recurrence showed longer Tpeak-Tend compared to arrhythmia-free patients (105 ± 14 ms vs. 91 ± 14 ms, p = 0.03). The combination of prolonged Tpeak-Tend (> 90 ms) and an early repolarization pattern was associated with a 12-fold increased risk of recurrent VA (p = 0.002). CONCLUSION:Prolonged Tpeak-Tend was associated with VA recurrence in patients with survived IVF. This correlation was even more pronounced in IVF patients with early repolarization pattern. The Tpeak-Tend interval might play a future role in risk stratification of patients with ERS.

Background: Recent studies reported an abbreviation of cardiac repolarization induced by sacubitril. Thus, the purpose of this study was to evaluate the electrophysiologic effects of sacubitril in the presence of drugs that shorten the QT interval. Methods and Results: 25 rabbit hearts were retrogradely perfused. After generating baseline data, hearts were allocated to two groups. In the first group (n = 12), the IK,ATP opener pinacidil (1 µM) significantly reduced action potential duration at 90% of repolarization (APD90), QT intervals and effective refractory periods (ERP). Additional administration of sacubitril (5 µM) slightly reduced APD90. The digitalis glycoside ouabain (0.2 µM) significantly shortened repolarization duration and refractory periods. Additional infusion of sacubitril abbreviated repolarization duration and ERP. Ventricular vulnerability was assessed by delivering premature extra stimuli and burst stimulation. Significantly more ventricular arrhythmias occurred with pinacidil (26 episodes vs. 5 episodes under baseline conditions, p < 0.05). Additional sacubitril treatment had no significant proarrhythmic effect (24 episodes). Ouabain alone did not provoke ventricular arrhythmias (6 episodes vs. 3 under baseline conditions, p = ns) whereas additional sacubitril treatment significantly increased the occurrence of VT episodes (29 episodes, p < 0.01). Conclusions: Sacubitril abbreviates cardiac repolarization in ouabain-pretreated hearts. While sacubitril had no proarrhythmic effect in the presence of pinacidil, the combination of sacubitril and ouabain amplified the arrhythmic risk. The underlying mechanism is a further abbreviation of refractory periods and cardiac repolarization that facilitate ventricular arrhythmias. These findings add further evidence to the proarrhythmic capacity of digitalis glycosides in the presence of other drugs that influence cardiac repolarization.

Availability of devices capable of continuous rhythm monitoring such as smartwatches, implantable loop recorders, or pacemakers/defibrillators is continuously increasing. Importantly, device detected “subclinical” atrial fibrillation seems to convey a significantly lower risk of thromboembolism than “clinical” atrial fibrillation verified by a conventional ECG recording. While current guidelines indicate a possible role of oral anticoagulation in selected high-risk patients with subclinical AF, recent trials show an ambiguous risk/benefit relationship of anticoagulation in this setting. The present review therefore summarizes current data on the role of oral anticoagulation in subclinical AF, aims at aiding in the decision process of anticoagulation, and illustrates current gaps in evidence regarding subclinical AF.

Electrical cardioversion represents a cornerstone of rhythm control strategies in patients with atrial fibrillation. However, in patients with obesity and specific anatomical variations, e.g. post heart transplantation, the standard flow of this procedure may need to be altered. This includes employing technical deviations of shock delivery and paying special attention to potential, unexpected complications. In light of the current position paper of the German Cardiac Society (Deutsche Gesellschaft für Kardiologie, DGK) on electrical cardioversion of atrial fibrillation, two cases with unconventional course of elective electrical cardioversion of atrial fibrillation are presented: dual direct current cardioversion in severe obesity and the occurrence of ventricular fibrillation in the presence of heterotopic heart transplant.

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.

Sarcoidosis is a multisystem disorder of unknown etiology. The leading hypothesis involves an antigen-triggered dysregulated T-cell-driven immunologic response leading to non-necrotic granulomas. In cardiac sarcoidosis (CS), the inflammatory response can lead to fibrosis, culminating in clinical manifestations such as atrioventricular block and ventricular arrhythmias. Cardiac manifestations frequently present as first and isolated signs or may appear in conjunction with extracardiac manifestations. The incidence of sudden cardiac death (SCD) is high. Diagnosis remains a challenge. For a definite diagnosis, endomyocardial biopsy (EMB) is suggested. In clinical practice, compatible findings in advanced imaging using cardiovascular magnetic resonance (CMR) and/or positron emission tomography (PET) in combination with extracardiac histological proof is considered sufficient. Management revolves around the control of myocardial inflammation by employing immunosuppression. However, data regarding efficacy are merely based on observational evidence. Prevention of SCD is of particular importance and several guidelines provide recommendations regarding device therapy. In patients with manifest CS, outcome data indicate a 5-year survival of around 90% and a 10-year survival in the range of 80%. Data for patients with silent CS are conflicting; some studies suggest an overall benign course of disease while others reported contrasting observations. Future research challenges involve better understanding of the immunologic pathogenesis of the disease for a targeted therapy, improving imaging to aid early diagnosis, assessing the need for screening of asymptomatic patients and randomized trials.

BackgroundThe use of SGLT-2 inhibitors has revolutionized heart failure therapy. Evidence suggests a reduced incidence of ventricular and atrial arrhythmias in patients with dapagliflozin or empagliflozin treatment. It is unclear to what extent the reduced arrhythmia burden is due to direct effects of the SGLT2 inhibitors or is solely a marker of improved cardiac function.MethodsOne hundred five rabbit hearts were allocated to eight groups and retrogradely perfused, employing a Langendorff setup. Action potential duration at 90% of repolarization (APD90), QT intervals, effective refractory periods, conduction velocity, and dispersion of repolarization were obtained with monophasic action potential catheters. A model for tachyarrhythmias was established with the IKr blocker erythromycin for QT prolongation associated proarrhythmia as well as the potassium channel opener pinacidil for a short-QT model. An atrial fibrillation (AF) model was created with isoproterenol and acetylcholine. With increasing concentrations of both SGLT2 inhibitors, reductions in QT intervals and APD90 were observed, accompanied by a slight increase in ventricular arrhythmia episodes. During drug-induced proarrhythmia, empagliflozin succeeded in decreasing QT intervals, APD90, and VT burden whereas dapagliflozin demonstrated no significant effects. In the presence of pinacidil induced arrhythmogenicity, neither SGLT2 inhibitor had a significant impact on cardiac electrophysiology. In the AF setting, perfusion with dapagliflozin showed significant suppression of AF in the course of restitution of electrophysiological parameters whereas empagliflozin showed no significant effect on atrial fibrillation incidence.ConclusionIn this model, empagliflozin and dapagliflozin demonstrated opposite antiarrhythmic properties. Empagliflozin reduced ventricular tachyarrhythmias whereas dapagliflozin showed effective suppression of atrial arrhythmias.

Antiviral therapies for treatment of COVID-19 may be associated with significant proarrhythmic potential. In the present study, the potential cardiotoxic side effects of these therapies were evaluated using a Langendorff model of the isolated rabbit heart. 51 hearts of female rabbits were retrogradely perfused, employing a Langendorff-setup. Eight catheters were placed endo- and epicardially to perform an electrophysiology study, thus obtaining cycle length-dependent action potential duration at 90

Catheter-based treatment of patients with ventricular arrhythmias (VA) reduces VA and mortality in selected patients. With regard to potential risks of catheter ablation, a benefit–risk assessment should be carried out. This can be performed with risk scores such as the recently published “Risk in Ventricular Ablation (RIVA) Score”. We sought to validate this score and to test for possible additional predictors in a large database of VT ablations. We analyzed 1964 catheter ablations for VA in patients with (1069; 54.4