Treatment Of Arrhythmias Research Articles

Circadian regulation of sinoatrial nodal cell pacemaking function: Dissecting the roles of autonomic control, body temperature, and local circadian rhythmicity.

Strong circadian (~24h) rhythms in heart rate (HR) are critical for flexible regulation of cardiac pacemaking function throughout the day. While this circadian flexibility in HR is sustained in diverse conditions, it declines with age, accompanied by reduced maximal HR performance. The intricate regulation of circadian HR involves the orchestration of the autonomic nervous system (ANS), circadian rhythms of body temperature (CRBT), and local circadian rhythmicity (LCR), which has not been fully understood. Here, we developed a mathematical model describing ANS, CRBT, and LCR in sinoatrial nodal cells (SANC) that accurately captures distinct circadian patterns in adult and aged mice. Our model underscores how the alliance among ANS, CRBT, and LCR achieves circadian flexibility to cover a wide range of firing rates in SANC, performance to achieve maximal firing rates, while preserving robustness to generate rhythmic firing patterns irrespective of external conditions. Specifically, while ANS dominates in promoting SANC flexibility and performance, CRBT and LCR act as primary and secondary boosters, respectively, to further enhance SANC flexibility and performance. Disruption of this alliance with age results in impaired SANC flexibility and performance, but not robustness. This unexpected outcome is primarily attributed to the age-related reduction in parasympathetic activities, which maintains SANC robustness while compromising flexibility. Our work sheds light on the critical alliance of ANS, CRBT, and LCR in regulating time-of-day cardiac pacemaking function and dysfunction, offering insights into novel therapeutic targets for the prevention and treatment of cardiac arrhythmias.

Post translational modifications of connexin 43 in ventricular arrhythmias after myocardial infarction.

Ventricular arrhythmias are the leading cause of sudden cardiac death in patients after myocardial infarction (MI). Connexin43 (Cx43) is the most important gap junction channel-forming protein in cardiomyocytes. Dysfunction of Cx43 contributes to impaired myocardial conduction and the development of ventricular arrhythmias. Following an MI, Cx43 undergoes structural remodeling, including expression abnormalities, and redistribution. These alterations detrimentally affect intercellular communication and electrical conduction within the myocardium, thereby increasing the susceptibility to post-infarction ventricular arrhythmias. Emerging evidence suggests that post-translational modifications play essential roles in Cx43 regulation after MI. Therefore, Cx43-targeted management has the potential to be a promising protective strategy for the prevention and treatment of post infarction ventricular arrhythmias. In this article, we primarily reviewed the regulatory mechanisms of Cx43 mediated post-translational modifications on post-infarction ventricular arrhythmias. Furthermore, Cx43-targeted therapy have also been discussed, providing insights into an innovative treatment strategy for ventricular arrhythmias after MI.

Treatment of heart rhythm disturbances associated with SARS-CoV-2 infection with anti-inflammatory drugs

Publications regarding cardiac arrhythmias associated with the new coronavirus infection (COVID-19) focus primarily on the high prevalence and symptoms of this complication. We have not found any studies on the specific treatment of arrhythmias associated with SARS-CoV2, since a standard therapeutic approach is probably implied. This observation describes a series of cases of various cardiac arrhythmias that occurred against the background of acute COVID-19 and were treated with anti-inflammatory, but not antiarrhythmic drugs. The cases are united by the occurrence of acute SARS-CoV-2 infection, the connection of relapses with inflammation symptoms, as well as the effectiveness of therapy with the main classes of anti-inflammatory drugs. A narrative review of the literature provides the rationale for the inflammatory theory of arrhythmias and sets the stage for discussion about how to integrate differentially anti-inflammatory drugs into the treatment regimen of such patients.

Initial experience, safety, and feasibility using remote access or onsite technical support for complex ablation procedures: results of the REMOTE study.

Electroanatomical mapping (EAM) systems are essential for the treatment of cardiac arrhythmias. The EAM system is usually operated by qualified staff or field technical engineers from the control room. Novel remote support technology allows for remote access of EAM via online services. Remote access increases the flexibility of the electrophysiological lab, reduces travel time, and overcomes hospital access limitations especially during the COVID-19 pandemic. Here, we report on the feasibility and safety of EAM remote access for cardiac ablation procedures. Mapping and ablation were achieved by combining the EnsiteX™ EAM system and the integrated Ensite™ Connect Remote Support software, together with an integrated audiovisual solution system for remote support (Medinbox). Communication between the operator and the remote support was achieved using an incorporated internet-based common communication platform (Zoom™), headphones, and high-resolution cameras. We investigated 50 remote access-assisted consecutive electrophysiological procedures from September 2022 to February 2023 (remote group). The data were compared with matched patients (n = 50) with onsite support from the control room (control group). The median procedure time was 100 min (76, 120; remote) vs. 86 min (60, 110; control), P = 0.090. The procedural success (both groups 100%, P = 0.999) and complication rate (remote: 2%, control: 0%, P = 0.553) were comparable between the groups. Travel burden could be reduced by 11 280 km. Remote access for EAM was feasible and safe in this single-centre study. Procedural data were comparable to procedures with onsite support. In the future, this new solution might have a great impact on facilitating electrophysiological procedures.

Directed Graph Mapping exceeds Phase Mapping for the detection of simulated 2D meandering rotors in fibrotic tissue with added noise

Cardiac arrhythmias such as atrial fibrillation (AF) are recognised to be associated with re-entry or rotors. A rotor is a wave of excitation in the cardiac tissue that wraps around its refractory tail, causing faster-than-normal periodic excitation. The detection of rotor centres is of crucial importance in guiding ablation strategies for the treatment of arrhythmia. The most popular technique for detecting rotor centres is Phase Mapping (PM), which detects phase singularities derived from the phase of a signal. This method has been proven to be prone to errors, especially in regimes of fibrotic tissue and temporal noise. Recently, a novel technique called Directed Graph Mapping (DGM) was developed to detect rotational activity such as rotors by creating a network of excitation. This research aims to compare the performance of advanced PM techniques versus DGM for the detection of rotors using 64 simulated 2D meandering rotors in the presence of various levels of fibrotic tissue and temporal noise. Four strategies were employed to compare the performances of PM and DGM. These included a visual analysis, a comparison of F2-scores and distance distributions, and calculating p-values using the mid-p McNemar test. Results indicate that in the case of low meandering, fibrosis and noise, PM and DGM yield excellent results and are comparable. However, in the case of high meandering, fibrosis and noise, PM is undeniably prone to errors, mainly in the form of an excess of false positives, resulting in low precision. In contrast, DGM is more robust against these factors as F2-scores remain high, yielding F2≥0.931 as opposed to the best PM F2≥0.635 across all 64 simulations.

A Multicenter Study of Stellate Ganglion Block as a Temporizing Treatment for Refractory Ventricular Arrhythmias

BackgroundVentricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions and can be refractory to conventional drug and device interventions. Stellate ganglion blockade (SGB) has been described as an adjunct, temporizing intervention in patients with refractory ventricular arrhythmia. We examined the association of SGB with VT/VF in a multicenter registry. ObjectivesThis study examined the efficacy of SGB for treatment/temporization of refractory VT/VF. MethodsThe authors present the first analysis from a multicenter registry of patients treated for refractory ventricular arrhythmia at a clinical site in the Czech Republic and the United States. Data were collected between 2016 and 2022. SGB was performed at the bedside by anesthesiologists and/or cardiologists. Outcomes of interest were VT/VF burden and defibrillations at 24 hours before and after SGB. ResultsIn total, there were 117 patients with refractory ventricular arrhythmias treated with SGB at Duke (n = 49) and the Institute for Clinical and Experimental Medicine (n = 68). The majority of patients were male (94.0%), were White (87.2%), and had an implantable cardioverter-defibrillator (70.1%). The most common etiology of heart disease was ischemic cardiomyopathy (52.1%), and monomorphic VT was the most common morphology (70.1%). Within 24 hours before SGB (0-24 hours), the median episodes of VT/VF were 7.5 (Q1-Q3: 3.0-27.0), and 24 hours after SGB, the median decreased to 1.0 (Q1-Q3: 0.0-4.5; P < 0.001). At 24 hours before SGB, the median defibrillation events were 2.0 (Q1-Q3: 0.0-8.0), and 24 hours after SGB, the median decreased to 0.0 (Q1-Q3: 0.0-1.0; P < 0.001). ConclusionsIn the largest cohort of patients with treatment-refractory ventricular arrhythmia, we demonstrate that SGB use was associated with a reduction in the ventricular arrhythmia burden and need for defibrillation therapy.

Utilizing Human-Induced Pluripotent Stem Cells to Study Cardiac Electroporation Pulsed-Field Ablation.

Electroporation is a promising nonthermal ablation method for cardiac arrhythmia treatment. Although initial clinical studies found electroporation pulsed-field ablation (PFA) both safe and efficacious, there are significant knowledge gaps concerning the mechanistic nature and electrophysiological consequences of cardiomyocyte electroporation, contributed by the paucity of suitable human in vitro models. Here, we aimed to establish and characterize a functional in vitro model based on human-induced pluripotent stem cells (hiPSCs)-derived cardiac tissue, and to study the fundamentals of cardiac PFA. hiPSC-derived cardiomyocytes were seeded as circular cell sheets and subjected to different PFA protocols. Detailed optical mapping, cellular, and molecular characterizations were performed to study PFA mechanisms and electrophysiological outcomes. PFA generated electrically silenced lesions within the hiPSC-derived cardiac circular cell sheets, resulting in areas of conduction block. Both reversible and irreversible electroporation components were identified. Significant electroporation reversibility was documented within 5 to 15-minutes post-PFA. Irreversibly electroporated regions persisted at 24-hours post-PFA. Per single pulse, high-frequency PFA was less efficacious than standard (monophasic) PFA, whereas increasing pulse-number augmented lesion size and diminished reversible electroporation. PFA augmentation could also be achieved by increasing extracellular Ca2+ levels. Flow-cytometry experiments revealed that regulated cell death played an important role following PFA. Assessing for PFA antiarrhythmic properties, sustainable lines of conduction block could be generated using PFA, which could either terminate or isolate arrhythmic activity in the hiPSC-derived cardiac circular cell sheets. Cardiac electroporation may be studied using hiPSC-derived cardiac tissue, providing novel insights into PFA temporal and electrophysiological characteristics, facilitating electroporation protocol optimization, screening for potential PFA-sensitizers, and investigating the mechanistic nature of PFA antiarrhythmic properties.

Ventricular Arrhythmias in Left Ventricular Assist Device Patients-Current Diagnostic and Therapeutic Considerations.

Left ventricular assist devices (LVAD) are used in the treatment of advanced left ventricular heart failure. LVAD can serve as a bridge to orthotopic heart transplantation or as a destination therapy in cases where orthotopic heart transplantation is contraindicated. Ventricular arrhythmias are frequently observed in patients with LVAD. This problem is further compounded as a result of diagnostic difficulties arising from presently available electrocardiographic methods. Due to artifacts from LVAD-generated electromagnetic fields, it can be challenging to assess the origin of arrhythmias in standard ECG tracings. In this article, we will review and discuss common mechanisms, diagnostics methods, and therapeutic strategies for ventricular arrhythmia treatment, as well as numerous problems we face in LVAD implant patients.

Non-invasive Neuromodulation of Arrhythmias.

Dysfunction of the cardiac autonomic nervous system (CANS) is associated with various cardiac arrhythmias. Subsequently, invasive techniques have successfully targeted the CANS for the treatment of certain arrhythmias, such as sympathetic denervation for ventricular tachycardia storm. Non-invasive strategies capable of modulating the CANS for arrhythmia treatment have begun to gain interest due to their low-risk profile and applicability as an adjuvant therapy. This review provides an evidence-based overview of the currently studied technologies capable of non-invasively modulating CANS for the suppression of atrial fibrillation and ventricular arrhythmias.

Clinical role of triggers and modulation factors of ventricular arrhythmogenesis in stable coronary artery disease

Ventricular arrhythmias are more commonly associated with coronary artery disease. However, ventricular arrhythmogenesis can be initiated by various trigger factors against its background. The substrate of arrhythmias in various nosological forms of stable coronary heart disease is heterogeneous. The patient may have stable exertional angina without severe fibrosis or have a history of myocardial infarction with significant scarring. Therefore the predictive value and prognostic significant of ventricular arrhythmias is not always unambiguous. Thus, for the successful treatment of arrhythmias as a main component of the prevention of sudden cardiac death, an individualized pathogenetic approach is the most important. The purpose of this article is to analyze and clinically interpret the results of studies, publications for 1980-2023, in which the authors describe the etiological, pathophysiological, pathomorphological characteristics of ventricular arrhythmias and their predictive value and prognostic significant for patients with stable coronary artery disease.

Clinical and instrumental characteristics of patients with a combination of obstructive sleep apnea and paroxysmal atrial fibrillation in different tactics of treatment of arrhythmia

Clinical and instrumental characteristics of patients with a combination of obstructive sleep apnea and paroxysmal atrial fibrillation in different tactics of treatment of arrhythmia

The dark side of arrhythmia treatment: iatrogenic tricuspid regurgitation and drug toxicity.

The dark side of arrhythmia treatment: iatrogenic tricuspid regurgitation and drug toxicity.

European guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death 2022: cardiomyopathy. What’s new?

The review provides information on new indications that should be guiden the diagnosis and treatment of ventricular arrhythmias in patients with cardiomyopathy. The analysis of modern definitions and classifications of cardiomyopathy is given. The issues of ventricular arrhythmias in different cardiomyopathy phenotypes, risk stratification of sudden cardiac death and its prevention are considered in detail.

A self-powered intracardiac pacemaker in swine model

Harvesting biomechanical energy from cardiac motion is an attractive power source for implantable bioelectronic devices. Here, we report a battery-free, transcatheter, self-powered intracardiac pacemaker based on the coupled effect of triboelectrification and electrostatic induction for the treatment of arrhythmia in large animal models. We show that the capsule-shaped device (1.75 g, 1.52 cc) can be integrated with a delivery catheter for implanting in the right ventricle of a swine through the intravenous route, which effectively converts cardiac motion energy to electricity and maintains endocardial pacing function during the three-week follow-up period. We measure in vivo open circuit voltage and short circuit current of the self-powered intracardiac pacemaker of about 6.0 V and 0.2 μA, respectively. This approach exhibits up-to-date progress in self-powered medical devices and it may overcome the inherent energy shortcomings of implantable pacemakers and other bioelectronic devices for therapy and sensing.

The effect of virtual interactive nurse-led support group intervention on fatigue, shock anxiety, and acceptance of implantable cardioverter defibrillator patients: a randomized trial

BackgroundImplantable cardioverter defibrillators (ICD), as a gold and standard treatment for fatal cardiac arrhythmia, may lead to some physical and psychological problems for the patients. Therefore, performing some interventions to reduce or eliminate these issues is crucial. This study aimed to determine the effect of virtual interactive nurse-led support group intervention on fatigue, shock anxiety, and acceptance of ICD patients.MethodsThis is a clinical trial study on 72 patients with ICD. They were randomly allocated to the intervention (n = 36) and control (n = 36) groups. A virtual interactive nurse-led support group intervention through WhasApp was performed for one month. Multidimensional fatigue inventory, Florida Shock Anxiety Scale, and Florida Patient Acceptance Scale were used. Data were analyzed to perform the analysis of data through SPSS, using independent and paired-t test, Mann-Whitney U test, Wilcoxon test, and ANCOVA.ResultsBefore the intervention, no significant difference was observed between the two groups with regard to fatigue, shock anxiety, and ICD acceptance. However, after the intervention, a significant difference was found between the two groups with regard to fatigue, shock anxiety, and ICD acceptance (P < 0.05).ConclusionThis study showed that virtual interactive nurse-led support group intervention reduced fatigue and shock anxiety and improved the ICD acceptance.Practice implicationsThis flexible, accessible, and interactive nurse-led support group intervention is suggested to be used for ICD patients.Trial registrationThis trial was registered and approved by Iranian Registry of Clinical Trials (Trial Id: 60,738, date: (24/02/2022). (https://www.irct.ir/trial/60738).

Acute antiarrhythmic effects of SGLT2 inhibitors–dapagliflozin lowers the excitability of atrial cardiomyocytes

In recent years, SGLT2 inhibitors have become an integral part of heart failure therapy, and several mechanisms contributing to cardiorenal protection have been identified. In this study, we place special emphasis on the atria and investigate acute electrophysiological effects of dapagliflozin to assess the antiarrhythmic potential of SGLT2 inhibitors. Direct electrophysiological effects of dapagliflozin were investigated in patch clamp experiments on isolated atrial cardiomyocytes. Acute treatment with elevated-dose dapagliflozin caused a significant reduction of the action potential inducibility, the amplitude and maximum upstroke velocity. The inhibitory effects were reproduced in human induced pluripotent stem cell-derived cardiomyocytes, and were more pronounced in atrial compared to ventricular cells. Hypothesizing that dapagliflozin directly affects the depolarization phase of atrial action potentials, we examined fast inward sodium currents in human atrial cardiomyocytes and found a significant decrease of peak sodium current densities by dapagliflozin, accompanied by a moderate inhibition of the transient outward potassium current. Translating these findings into a porcine large animal model, acute elevated-dose dapagliflozin treatment caused an atrial-dominant reduction of myocardial conduction velocity in vivo. This could be utilized for both, acute cardioversion of paroxysmal atrial fibrillation episodes and rhythm control of persistent atrial fibrillation. In this study, we show that dapagliflozin alters the excitability of atrial cardiomyocytes by direct inhibition of peak sodium currents. In vivo, dapagliflozin exerts antiarrhythmic effects, revealing a potential new additional role of SGLT2 inhibitors in the treatment of atrial arrhythmias.

Pulsed Field Ablation in the Treatment of Cardiac Arrhythmias: A State-of-the-art Review

Abstract Pulsed-field ablation (PFA), specifically irreversible electroporation, induces cell membrane damage through the formation of irreversible pores, leading to apoptosis and necrosis, with applications in tumor treatment and myocardium ablation since 2007. This review is on PFA in the treatment of cardiac arrhythmias, including the basic principles, clinical applications, and hot issues of PFA. Presently, the pulsed electric field has demonstrated its effectiveness and safety in the treatment of atrial fibrillation, which is not inferior to that of traditional thermal energy. Research and application on pulsed electric ablation is rapidly advancing due to its advantages of rapidity and specificity in lesion creation. Moreover, pulsed electric ablation has reduced the difficulty of catheter manipulation in pulmonary vein isolation, making it an available treatment to benefit more patients.

Current Status and Challenges of Interventional Therapy for Diagnosis and Treatment of Arrhythmia in China

Abstract There are a large number of arrhythmia patients in China, and the field of interventional therapy for the diagnosis and treatment of arrhythmia has developed rapidly and made remarkable achievements. It is currently in a steady growth trend. In 2021, a total of 99,306 cases of pacemaker, 6547 cases of implantable cardioverter defibrillator, 5333 cases of cardiac resynchronization therapy, and 210,609 cases of catheter ablation were registered in the direct reporting system of arrhythmia interventional therapy information network, all of which increased significantly relative to those in 2020. However, there remains a considerable gap when in comparison with advanced countries. Therefore, there is an urgent need to widely implement and standardize advanced arrhythmia diagnosis and treatment techniques. In the future, it is vital to improve the training and development of arrhythmia physicians and teams, advance graded diagnosis and treatment, and foster international cooperation. In addition, there is a growing demand for increased clinical research to guide practical applications and the promotion of new technologies and devices for arrhythmia diagnosis and treatment.

Best practices in robotic magnetic navigation-guided catheter ablation of cardiac arrhythmias, a position paper of the Society for Cardiac Robotic Navigation.

Robotic magnetic navigation (RMN)-guided catheter ablation (CA) technology has been used for the treatment of cardiac arrhythmias for almost 20 years. Various studies reported that RMN allows for high catheter stability, improved lesion formation and a superior safety profile. So far, no guidelines or recommendations on RMN-guided CA have been published. The aim of this consensus paper was to summarize knowledge and provide recommendations on management of arrhythmias using RMN-guided CA as treatment of atrial fibrillation (AF) and ventricular arrhythmias (VA). An expert writing group, performed a detailed review of available literature, and drawing on their own experience, drafted and voted on recommendations and summarized current knowledge and practice in the field. Recommendations on RMN-guided CA are presented in a guideline format with three levels of recommendations to serve as a reference for best practices in RMN procedures. Each recommendation is accompanied by supportive text and references. The various sections cover the practical spectrum from system and patient set-up, EP laboratory staffing, combination of RMN with fluoroscopy and mapping systems, use of automation features and ablation settings and targets, for different cardiac arrhythmias. This manuscript, presenting the combined experience of expert robotic users and knowledge from the available literature, offers a unique resource for providers interested in the use of RMN in the treatment of cardiac arrhythmias.

Application of Different Types of Electrocardiogram Monitoring in Arrhythmias

Abstract Arrhythmias are a common cardiovascular disease with multiple clinical manifestations, of which ventricular arrhythmias may indicate the risk of sudden cardiac death. Although great progress has been made in the treatment of ventricular arrhythmias, there is still no solution for sudden malignant arrhythmic events. Portable electrocardiogram (ECG) monitoring tools play a vital role in the process of monitoring spontaneous arrhythmias, especially in early cardiovascular diseases without clinical symptoms, the use of ECG monitoring tools can provide more timely and accurate observation of the occurrence of occult arrhythmias. This mini-review summarizes the application of ECG monitoring tools in the process of arrhythmias and provides a potential reference for monitoring the occurrence of early arrhythmias.