Use of class IC antiarrhythmic drugs in patients with structural heart disease and implantable cardioverter defibrillator.

BACKGROUND: Due to suspected pro-arrhythmic effects and increased mortality associated with class-IC antiarrhythmic drugs (AADs) in previous trials, AAD therapy in structural heart disease (SHD) is mainly restricted to amiodarone. In the presence of diagnostic and therapeutic advancements in cardiovascular medicine, it remains unclear if previous studies adequately reflect contemporary patients. In clinical practice, class-IC-AADs are occasionally used in individual cases, particularly in patients with an implantable cardioverter defibrillator (ICD). METHODS: This study retrospectively investigated outcome in ICD-carriers with SHD in whom class-IC-AADs were used as an individualized therapy due to failure, side effects, or unacceptable risk of alternative therapeutic options. RESULTS: Fifty patients from four tertiary centers were included (median age 48.5 years; 52% female). The most common underlying SHD were dilated (42%) or ischemic cardiomyopathy (26%) (median LVEF = 45%). Indications for AAD were sustained ventricular arrhythmias (VA) (58%), symptomatic premature ventricular contractions (26%), or atrial arrhythmias (16%). Median follow-up was 27.8 months. Freedom from sustained VA was 72%, and freedom from ICD therapy was 80%. In 19 patients (38%), AAD therapy was terminated. The most common reason was insufficient efficacy (n = 8). Pro-arrhythmia was suspected in three patients. Five patients died during follow-up (10.0%), two of cardiovascular cause (4.0%). CONCLUSION: In a multicenter cohort of ICD-carriers with SHD, class-IC-AADs were associated with a low rate of pro-arrhythmic effects or cardiovascular mortality. The majority of patients remained free from sustained VA during a follow-up of > 2 years. Further efforts should be made to evaluate the safety of class-IC-AADs in SHD patients receiving contemporary cardiovascular therapy.

Implementation of the multielectrode radiofrequency-balloon in real-world clinical practice-operator learning curve and procedural outcome at a high-volume center.

Background: The novel multielectrode radiofrequency (RF) balloon catheter (HELIOSTAR™, Biosense Webster) is a new technology for pulmonary vein isolation (PVI) in atrial fibrillation (AF), combining RF-ablation and 3D-mapping visualization with the concept of a "single-shot"-ablation device. This study evaluates the operator learning curve und procedural outcome during implementation of the multielectrode RF-balloon at a high-volume center. Methods: The first 40 patients undergoing PVI by multielectrode RF-balloon catheter at Heidelberg University Hospital were included in this prospective study. Procedural outcome was analyzed over the course of increasing experience with the device. Results: 157/157 pulmonary veins (PVs) were successfully isolated with the RF-balloon catheter, in 73.2% by a single RF-application. Median time to isolation (TTI) was 11.0 s (Q1 = 8.0 s; Q3 = 13.8 s). Median procedure time was 62.5 min (Q1 = 50.0 min; Q3 = 70.5 min). LA-dwell time was 28.5 min (Q1 = 23.3 min; Q3 = 36.5 min). Median fluoroscopy duration was 11.6 min (Q1 = 10.1 min; Q3 = 13.7 min). No serious procedure-related complications were observed, apart from one case of unclear, post-procedural acute-on-chronic kidney injury. With increasing operator experience, an additional reduction in procedure duration was observed. Conclusion: Rapid implementation of a "single shot"-ablation device combining RF-ablation and 3D-mapping can be achieved with high acute procedural efficacy and safety at a high-volume center. Previous experience with "single-shot" ablation devices may be advantageous for time-efficient introduction of the novel RF-balloon catheter into clinical practice. Clinical Trial Registration: ClinicalTrials.gov; Identifier NCT0560361.

Length of hospital stay for elective electrophysiological procedures: a survey from the European Heart Rhythm Association.

AIMS: Electrophysiological (EP) operations that have traditionally involved long hospital lengths of stay (LOS) are now being undertaken as day case procedures. The coronavirus disease-19 pandemic served as an impetus for many centres to shorten LOS for EP procedures. This survey explores LOS for elective EP procedures in the modern era. METHODS AND RESULTS: An online survey consisting of 27 multiple-choice questions was completed by 245 respondents from 35 countries. With respect to de novo cardiac implantable electronic device (CIED) implantations, day case procedures were reported for 79.5% of implantable loop recorders, 13.3% of pacemakers (PMs), 10.4% of implantable cardioverter defibrillators (ICDs), and 10.2% of cardiac resynchronization therapy (CRT) devices. With respect to CIED generator replacements, day case procedures were reported for 61.7% of PMs, 49.2% of ICDs, and 48.2% of CRT devices. With regard to ablations, day case procedures were reported for 5.7% of atrial fibrillation (AF) ablations, 10.7% of left-sided ablations, and 17.5% of right-sided ablations. A LOS ≥ 2 days for CIED implantation was reported for 47.7% of PM, 54.5% of ICDs, and 56.9% of CRT devices and for 54.5% of AF ablations, 42.2% of right-sided ablations, and 46.1% of left-sided ablations. Reimbursement (43-56%) and bed availability (20-47%) were reported to have no consistent impact on the organization of elective procedures. CONCLUSION: There is a wide variation in the LOS for elective EP procedures. The LOS for some procedures appears disproportionate to their complexity. Neither reimbursement nor bed availability consistently influenced LOS.

Catheter Ablation of Atrial Fibrillation in Patients With Heart Failure and Preserved Ejection Fraction.

BACKGROUND: Coexistence of atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) is common, affecting morbidity and prognosis. This study evaluates outcome after cryoballoon ablation for AF in HFpEF compared with patients without heart failure. METHODS: A total of 102 AF patients with left ventricular ejection fraction ≥50% undergoing cryoballoon ablation were prospectively enrolled. Baseline evaluation included echocardiography, stress echocardiography, 6-minute walk test, biomarkers, and quality of life assessment (Short-Form-36). Procedural parameters and clinical, functional and echocardiographic end points at follow-up ≥12 months after AF ablation were compared between patients with and without HFpEF. RESULTS: Patients with HFpEF (n=24) were older (median, 74 years versus 65 years; P=0.001) more often female (83% versus 28%; P<0.001) and characterized by more pronounced AF-related symptoms (median European Heart Rhythm Association score 3 versus 2; P<0.001), higher left atrial pressures (median, 14 mm Hg versus 10 mm Hg; P=0.008), reduced left atrial-appendage velocity (median, 36 cm/s versus 59 cm/s; P<0.001), and reduced distance in the 6-minute walk test (median, 488 m versus 539 m; P<0.001). Patients with HFpEF more often experienced AF recurrence (57% versus 23%; P=0.003), repeat AF ablation (39% versus 14%; P=0.01) and AF-related rehospitalization (26% versus 7%; P=0.016). Heart failure symptoms and elevated cardiac biomarkers persisted, even in patients with HFpEF with successful rhythm control at follow-up. Echocardiographic follow-up showed progression of adverse left atrial remodeling and no relevant improvement in diastolic function in HFpEF. Quality of life improved in patients without HFpEF, whereas patients with HFpEF still exhibited a lower physical component summary score (median, 41.5 versus 53.4; P<0.004). CONCLUSIONS: Patients with HFpEF constitute a distinct subgroup with elevated risk for AF recurrence after cryoballon ablation. Functional hallmarks of HFpEF persist, irrespective of rhythm status at follow-up. Future research is needed to optimize treatment strategies in patients with HFpEF. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04317911.

Sudden cardiac death while waiting: do we need the wearable cardioverter-defibrillator?

Sudden cardiac death (SCD) is the most frequent cause of cardiovascular death in industrialized nations. Patients with cardiomyopathy are at increased risk for SCD and may benefit from an implantable cardioverter-defibrillator (ICD). The risk of SCD is highest in the first months after myocardial infarction or first diagnosis of severe non-ischemic cardiomyopathy. On the other hand, left ventricular function may improve in a subset of patients to such an extent that an ICD might no longer be needed. To offer protection from a transient risk of SCD, the wearable cardioverter-defibrillator (WCD) is available. Results of the first randomized clinical trial investigating the role of the WCD after myocardial infarction were recently published. This review is intended to provide insight into data from the VEST trial, and to put these into perspective with studies and clinical experience. As a non-invasive, temporary therapy, the WCD may offer advantages over early ICD implantation. However, recent data demonstrate that patient compliance and education play a crucial role in this new concept of preventing SCD.

[Interpretation of paced ECGs by the wearable defibrillator : Pitfalls and solutions]. / Interpretation von Schrittmacher-EKGs durch die tragbare Defibrillatorweste : Fallstricke und Lösungen.

The wearable cardioverter defibrillator (WCD) can protect patients against sudden cardiac death during temporarily increased or unknown risk of ventricular arrhythmias or in the situation of implantable cardioverter-defibrillator (ICD) explantation due to infection. In unusual cases, misinterpretation of the ECG by the tachycardia detection and discrimination algorithm of the WCD can occur which can lead to inappropriate acoustic alerts or inappropriate WCD therapy. We explain the mechanisms of inappropriate WCD therapy in two cases from daily clinical practice together with potential strategies to avoid such events in this special group of patients.

Predictors and Prognostic Implications of Cardiac Arrhythmias in Patients Hospitalized for COVID-19.

BACKGROUND: Cardiac manifestation of COVID-19 has been reported during the COVID pandemic. The role of cardiac arrhythmias in COVID-19 is insufficiently understood. This study assesses the incidence of cardiac arrhythmias and their prognostic implications in hospitalized COVID-19-patients. METHODS: A total of 166 patients from eight centers who were hospitalized for COVID-19 from 03/2020-06/2020 were included. Medical records were systematically analyzed for baseline characteristics, biomarkers, cardiac arrhythmias and clinical outcome parameters related to the index hospitalization. Predisposing risk factors for arrhythmias were identified. Furthermore, the influence of arrhythmia on the course of disease and related outcomes was assessed using univariate and multiple regression analyses. RESULTS: Arrhythmias were detected in 20.5% of patients. Atrial fibrillation was the most common arrhythmia. Age and cardiovascular disease were predictors for new-onset arrhythmia. Arrhythmia was associated with a pronounced increase in cardiac biomarkers, prolonged hospitalization, and admission to intensive- or intermediate-care-units, mechanical ventilation and in-hospital mortality. In multiple regression analyses, incident arrhythmia was strongly associated with duration of hospitalization and mechanical ventilation. Cardiovascular disease was associated with increased mortality. CONCLUSIONS: Arrhythmia was the most common cardiac event in association with hospitalization for COVID-19. Older age and cardiovascular disease predisposed for arrhythmia during hospitalization. Whereas in-hospital mortality is affected by underlying cardiovascular conditions, arrhythmia during hospitalization for COVID-19 is independently associated with prolonged hospitalization and mechanical ventilation. Thus, incident arrhythmia may indicate a patient subgroup at risk for a severe course of disease.

Ablation of Atrial Fibrillation in Patients with Hypertension-An Analysis from the German Ablation Registry.

BACKGROUND: Hypertension (HTN) constitutes a risk factor for the development of atrial fibrillation (AF), as well as for thromboembolic and bleeding events. We analysed the outcome after catheter ablation of AF in HTN in a cohort from the prospective multicenter German Ablation Registry. METHODS: Between 03/2008 and 01/2010, 626 patients undergoing AF-ablation were analysed. Patients diagnosed with HTN (n = 386) were compared with patients without HTN (n = 240) with respect to baseline, procedural and long-term outcome parameters. RESULTS: Patients with HTN were older and more often presented with persistent forms of AF and cardiac comorbidities. Major and moderate in-hospital complications were low. At long-term follow-up, major cardiovascular events were rare in both groups. Rates of AF-recurrence, freedom from antiarrhythmic medication and repeat ablation were not statistically different between groups. Most patients reported improvement of symptoms and satisfaction with the treatment. However, patients with HTN more frequently complained of dyspnea of New York Heart Association (NYHA) class ≥ II and angina. They were more often rehospitalized, particularly when persistent AF had been diagnosed. CONCLUSION: Catheter ablation of AF is associated with low complication rates and favorable arrhythmia-related results in patients with HTN. Residual clinical symptoms may be due to cardiac comorbidities and require additional attention in this important subgroup of AF-patients.

Symptomatic arrhythmias after catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT): results from the German Ablation Registry.

BACKGROUND: In atrioventricular nodal reentrant tachycardia (AVNRT), catheter ablation is considered as first-line therapy. Despite high success rates, some patients present with arrhythmia recurrence or develop other types of arrhythmias over time. OBJECTIVE: To assess the incidence of symptomatic arrhythmias after initially successful AVNRT ablation and to analyze their clinical implications in a real-world cohort. METHODS: We included 2,795 patients from the German Ablation Registry undergoing first ablation of AVNRT between 01/2007 and 01/2010. In patients alive at long-term follow-up, patient-specific characteristics and long-term follow-up data were compared between patients with (group A) and without (group B) any symptomatic arrhythmia during follow-up. RESULTS: Symptomatic arrhythmias occurred in 17.2% of patients during a mean follow-up of 678 days after AVNRT ablation. The patients with symptomatic arrhythmias were more often female and suffered from structural heart disease. Arrhythmia occurrence was clinically relevant regarding symptoms and patient satisfaction. Serious adverse events including stroke, transient ischemic attack, pacemaker implantation, as well as continued use of antiarrhythmic medication occurred more often in group A. A second ablation procedure was performed in 26% of symptomatic patients to optimize the symptomatic outcome, whereas cardiovascular events or patient satisfaction were not further improved. CONCLUSION: During long-term follow-up, one out of six patients experienced symptomatic arrhythmias after AVNRT ablation, associated with an increase of serious adverse events. A subset of patients required medical or interventional antiarrhythmic therapy, possibly attributable to the co-existence of other arrhythmias. Screening for arrhythmic and cardiac co-morbidity before and after ablation may support comprehensive therapy planning and outcome.

Use of the wearable cardioverter-defibrillator (WCD) and WCD-based remote rhythm monitoring in a real-life patient cohort.

The wearable cardioverter-defibrillator (WCD) was introduced to provide protection from sudden cardiac death (SCD) in patients with transiently elevated risk or during ongoing risk stratification. Benefits and clinical characteristics of routine WCD use remain to be assessed in larger patient populations. This study aims to identify determinants of WCD compliance, therapies, and inappropriate alarms in a real-life cohort. A total of 106 cases (68.9% male) were included between 11/2010 and 04/2016. WCD therapies, automatically recorded arrhythmia episodes, inappropriate WCD alarms, patient compliance, and outcome after WCD prescription were analyzed. Median duration of WCD use was 58.5 days. Average daily wearing time was 22.7 h. Compliance was reduced in patients ≤ 50 years. Three patients received WCD therapies (2.8%). In one case ventricular fibrillation (VF) was appropriately terminated with the first shock. Two patients received inappropriate WCD therapies due to WCD algorithm activation during ventricular pacemaker stimulation. One patient died of asystole while carrying a WCD (0.9%). Additional arrhythmias detected comprised self-terminating sustained ventricular tachycardia (VT; 2.8%), non-sustained VT (2.8%), and supraventricular arrhythmias (5.7%). Inappropriate WCD alarms due to over-/undersensing occurred in 77/106 patients (72.6%), of which 41 (38.7%) experienced ≥ 10 inappropriate WCD alarms during the prescription period. Thirteen patients (12.3%) displayed a mean of > 1 inappropriate alarms/day. WCD use was associated with high compliance and provided protection from VT/VF-related SCD. The majority of patients experienced inappropriate WCD alarms. Alterations in QRS morphology during pacemaker stimulation require consideration in WCD programming to prevent inappropriate alarms.

Fully digital data processing during cardiovascular implantable electronic device follow-up in a high-volume tertiary center.

BACKGROUND: Increasing numbers of patients with cardiovascular implantable electronic devices (CIEDs) and limited follow-up capacities highlight unmet challenges in clinical electrophysiology. Integrated software (MediConnect®) enabling fully digital processing of device interrogation data has been commercially developed to facilitate follow-up visits. We sought to assess feasibility of fully digital data processing (FDDP) during ambulatory device follow-up in a high-volume tertiary hospital to provide guidance for future users of FDDP software. METHODS: A total of 391 patients (mean age, 70 years) presenting to the outpatient department for routine device follow-up were analyzed (pacemaker, 44%; implantable cardioverter defibrillator, 39%; cardiac resynchronization therapy device, 16%). RESULTS: Quality of data transfer and follow-up duration were compared between digital (n = 265) and manual processing of device data (n = 126). Digital data import was successful, complete and correct in 82% of cases when early software versions were used. When using the most recent software version the rate of successful digital data import increased to 100%. Software-based import of interrogation data was complete and without failure in 97% of cases. The mean duration of a follow-up visit did not differ between the two groups (digital 18.7 min vs. manual data transfer 18.2 min). CONCLUSIONS: FDDP software was successfully implemented into the ambulatory follow-up of patients with implanted pacemakers and defibrillators. Digital data import into electronic patient management software was feasible and supported the physician's workflow. The total duration of follow-up visits comprising technical device interrogation and clinical actions was not affected in the present tertiary center outpatient cohort.

Sex-related outcome of atrial fibrillation ablation: Insights from the German Ablation Registry.

BACKGROUND: Stratification of patients with atrial fibrillation (AF) according to mechanistic and prognostic criteria may optimize the effectiveness and safety of catheter ablation. In women, AF is associated with more severe symptoms and worse prognosis. OBJECTIVE: We sought to assess sex-related differences in catheter ablation procedures and outcome in a large cohort of patients with AF. METHODS: A total of 3652 patients (1198 women [33%]; 2454 men [67%]) included in the German Ablation Registry were analyzed. Periprocedural parameters and outcome at 12-month follow-up were compared between male and female patients. RESULTS: Women were older at the time of ablation (women: 63.6 years; men: 59.1 years; P < .0001) and exhibited a higher prevalence of paroxysmal AF (women: 72%; men: 61%; P < .0001). They were less often affected by cardiovascular disease and reduced left ventricular function. Energy application duration and overall procedure duration were shorter in women. Conversely, the rate of major inhospital complications was increased in female patients (1.9% vs 0.8%; P = .023) and mainly driven by major bleeding events. At follow-up, women experienced higher AF recurrence rates (women: 50%; men: 45%; P = .017) and more often received oral medication for rhythm and rate control. In addition, the rate of pacemaker implantation was higher in the female cohort. Women more frequently reported femoral access site complications (women: 6%; men: 3%; P < .001). Overall, male patients were more often free from AF-related symptoms and satisfied with the treatment. CONCLUSION: Catheter ablation of AF was associated with a distinct sex-related outcome and complication profile that requires consideration in clinical practice.

Catheter ablation of atrial fibrillation in patients with concomitant sinus bradycardia-Insights from the German Ablation Registry.

AIMS: This investigation addresses procedural characteristics of catheter ablation in patients with atrial fibrillation (AF) and sinus bradycardia. METHODS: From the prospective, multi-center German Ablation Registry 1073 patients with sinus rhythm at the time of AF ablation were divided into two groups according to heart rate at start of procedure (A, <60 beats per minute (bpm), n=197; B, 60-99bpm, n=876). RESULTS: Acute procedural success was high (≥98%) and similar between groups. Procedure duration and energy application time were increased in group A (180min vs. 155min and 2561s vs. 1879s, respectively). Major complications were more frequent in group A (2.2% vs. 0.5%), and a greater proportion of these patients was discharged under antiarrhythmic medication (64% vs. 52%). CONCLUSION: Catheter ablation of AF with concomitant sinus bradycardia is associated with high procedural efficacy, longer procedure- and energy application durations, and a slightly elevated complication rate.

Prevalence of intracardiac thrombi under phenprocoumon, direct oral anticoagulants (dabigatran and rivaroxaban), and bridging therapy in patients with atrial fibrillation and flutter.

Direct oral anticoagulants (DOACs) are effective for stroke prevention in nonvalvular atrial fibrillation (AF). Cardioversion (CV) is frequently performed in patients with AF or flutter. To further explore the safety profile of DOACs in the context of CV, we sought to assess the prevalence of intracardiac thrombi under DOAC therapy in comparison with treatment with vitamin K antagonists. A total of 672 transesophageal echocardiograms performed in 643 patients with a history of nonvalvular AF were analyzed. The median CHA2DS2-VASc score was 4. Cases were stratified according to anticoagulation with dabigatran (n = 79), rivaroxaban (n = 122), phenprocoumon (n = 180), or bridging therapy (n = 287). In a subgroup analysis, only patients receiving phenprocoumon with an international normalized ratio ≥2 on the day of the investigation or on DOAC therapy for ≥3 weeks were considered. The prevalence of intracardiac thrombi under phenprocoumon was significantly higher than under DOACs (phenprocoumon, 17.8%; all DOACs, 3.9%; dabigatran, 3.8%; rivaroxaban, 4.1%) and showed no significant difference to bridging therapy (12.5%). In patients with sufficient short-term anticoagulation, similar differences between DOAC and phenprocoumon groups were observed (phenprocoumon, 18.4%; all DOACs, 3.8%; dabigatran, 0%; rivaroxaban, 6.6%). The influence of anticoagulation medication on thrombus rates was confirmed after adjusting for baseline intergroup differences regarding left atrial size and CHA2DS2-VASc score. In conclusion, the prevalence of intracardiac thrombi was lower under DOAC therapy than under phenprocoumon in this high-risk patient cohort. Safety of CV during DOAC treatment requires further prospective evaluation.

Cholinergic plasticity of oscillating neuronal assemblies in mouse hippocampal slices.

The mammalian hippocampus expresses several types of network oscillations which entrain neurons into transiently stable assemblies. These groups of co-active neurons are believed to support the formation, consolidation and recall of context-dependent memories. Formation of new assemblies occurs during theta- and gamma-oscillations under conditions of high cholinergic activity. Memory consolidation is linked to sharp wave-ripple oscillations (SPW-R) during decreased cholinergic tone. We hypothesized that increased cholinergic tone supports plastic changes of assemblies while low cholinergic tone favors their stability. Coherent spatiotemporal network patterns were measured during SPW-R activity in mouse hippocampal slices. We compared neuronal activity within the oscillating assemblies before and after a transient phase of carbachol-induced gamma oscillations. Single units maintained their coupling to SPW-R throughout the experiment and could be re-identified after the transient phase of gamma oscillations. However, the frequency of SPW-R-related unit firing was enhanced after muscarinic stimulation. At the network level, these changes resulted in altered patterns of extracellularly recorded SPW-R waveforms. In contrast, recording of ongoing SPW-R activity without intermittent cholinergic stimulation revealed remarkably stable repetitive activation of assemblies. These results show that activation of cholinergic receptors induces plasticity at the level of oscillating hippocampal assemblies, in line with the different role of gamma- and SPW-R network activity for memory formation and -consolidation, respectively.

Tonic GABAergic control of mouse dentate granule cells during postnatal development.

The dentate gyrus is the main hippocampal input structure receiving strong excitatory cortical afferents via the perforant path. Therefore, inhibition at this 'hippocampal gate' is important, particularly during postnatal development, when the hippocampal network is prone to seizures. The present study describes the development of tonic GABAergic inhibition in mouse dentate gyrus. A prominent tonic GABAergic component was already present at early postnatal stages (postnatal day 3), in contrast to the slowly developing phasic postsynaptic GABAergic currents. Tonic currents were mediated by GABA(A) receptors containing α(5)- and δ-subunits, which are sensitive to low ambient GABA concentrations. The extracellular GABA level was determined by synaptic GABA release and GABA uptake via the GABA transporter 1. The contribution of these main regulatory components was surprisingly stable during postnatal granule cell maturation. Throughout postnatal development, tonic GABAergic signals were inhibitory. They increased the action potential threshold of granule cells and reduced network excitability, starting as early as postnatal day 3. Thus, tonic inhibition is already functional at early developmental stages and plays a key role in regulating the excitation/inhibition balance of both the adult and the maturing dentate gyrus.