Field Of Cardiac Electrophysiology Research Articles

Transseptal Puncture Guided by Three-Dimensional Electroanatomical Mapping: Early Experience Using a Simplified Approach in Adults with Congenital Heart Disease.

The widespread use of three-dimensional (3D) mapping systems and echocardiography in the field of cardiac electrophysiology has made it possible to perform transseptal punctures (TSP) with low or no fluoroscopy. However, such attempts in adults with congenital heart disease (ACHD) who have previously undergone surgical or interventional treatment are limited. Therefore, we sought to explore the feasibility and safety of an approach to perform zero- or low-fluoroscopy TSP in ACHD patients undergoing left atrial cardiac ablation procedures. This study included 45 ACHD patients who underwent TSP for ablation of left-sided tachycardias (left atrium or pulmonary venous atrium). Computed tomography (CT) of the heart was performed in all patients prior to ablation. 3D mapping of the right-sided heart chambers before TSP was used to superimpose the registered anatomy, which was subsequently used for the mapping-guided TSP technique. TSP was performed with zero-fluoroscopy in 27 patients, and the remaining 18 patients had a mean fluoroscopy exposure of 315.88 ± 598.43 μGy.m2 and a mean fluoroscopy duration of 1.9 ± 5.4 min. No patient in this cohort experienced TSP-related complications. Our study describes a fluoroscopy-free or low-dose fluoroscopy approach for TSP in ACHD patients undergoing catheter ablation of left-sided tachyarrhythmias who had been previously treated surgically or interventionally due to congenital heart defects. By superimposing 3D electroanatomic mapping with cardiac CT anatomy, this protocol proved to be highly effective, feasible and safe.

MP-453092-1 FEASIBILITY OF REMOTE MAPPING AND CLINICAL SUPPORT USING NOVEL SOFTWARE

Covid redefined how the world functions. The electrophysiology (EP) community identified multiple needs that arose due to this paradigm and redefined workflows. The geographic paucity of experienced clinical mapping support was a crucial issue that limited the worldwide adoption of complex ablation procedures. To ascertain the feasibility and safety of utilizing a novel software for remote mapping and remote clinical support for all spectrums of cardiac ablation procedures and to compare the adoption of ablation technology in that geography. Ablation procedures performed at Metromed International Cardiac Centre (MICC), India were included in this early feasibility analysis (EFA). All procedures were performed by a single EP operator. Remote Clinical support was provided by an EP physician (primary operator's sibling) in the USA. All mapping was performed by an experienced mapper from a remote location 400 miles away from the primary EP operator in India. The mapping system utilized was Ensite Precision with SJM Connect software. 300 contiguous ablation procedures from 2020 to 2022 were included in this EFA. The proprietory SJM Connect software allows remote access to the Ensite console via a secured connection. The software requires the operator to be granted access to the Ensite console via a permission request that must be acknowledged on the Ensite Console. The software will then allow the remote operator to levels of access to the system, view-only access, or complete control of the console to provide full remote support. Communication occurs between the remote user and the console via a chat function and over a voice call. This remote connection can be terminated at any time from either the console or the remote operator. There is no PHI displayed. Results detailing case demographics and acute procedural success and safety will be presented. Results comparing the adoption of ablation technology with the previous 3 years in this geography will be presented. This EFA demonstrates the safety and efficacy of using remote clinical support and remote mapping for ablation procedures. This opens a world of possibilities including the expansion of ablation technology to all corridors of the world with experienced clinical and mapping support connecting the EP community on a worldwide platform. Additional studies and strategies are needed to further understand the implication of remote support algorithms in bridging the healthcare gaps in the field of cardiac EP.

Economic evaluation in cardiac electrophysiology: Determining the value of emerging technologies.

Cardiac electrophysiology is a constantly evolving speciality that has benefited from technological innovation and refinements over the past several decades. Despite the potential of these technologies to reshape patient care, their upfront costs pose a challenge to health policymakers who are responsible for the assessment of the novel technology in the context of increasingly limited resources. In this context, it is critical for new therapies or technologies to demonstrate that the measured improvement in patients' outcomes for the cost of achieving that improvement is within conventional benchmarks for acceptable health care value. The field of Health Economics, specifically economic evaluation methods, facilitates this assessment of value in health care. In this review, we provide an overview of the basic principles of economic evaluation and provide historical applications within the field of cardiac electrophysiology. Specifically, the cost-effectiveness of catheter ablation for both atrial fibrillation (AF) and ventricular tachycardia, novel oral anticoagulants for stroke prevention in AF, left atrial appendage occlusion devices, implantable cardioverter defibrillators, and cardiac resynchronization therapy will be reviewed.

Emerging methods to model cardiac ion channel and myocyte electrophysiology.

In the field of cardiac electrophysiology, modeling has played a central role for many decades. However, even though the effort is well-established, it has recently seen a rapid and sustained evolution in the complexity and predictive power of the models being created. In particular, new approaches to modeling have allowed the tracking of parallel and interconnected processes that span from the nanometers and femtoseconds that determine ion channel gating to the centimeters and minutes needed to describe an arrhythmia. The connection between scales has brought unprecedented insight into cardiac arrhythmia mechanisms and drug therapies. This review focuses on the generation of these models from first principles, generation of detailed models to describe ion channel kinetics, algorithms to create and numerically solve kinetic models, and new approaches toward data gathering that parameterize these models. While we focus on application of these models for cardiac arrhythmia, these concepts are widely applicable to model the physiology and pathophysiology of any excitable cell.

Smoothness and continuity of cost functionals for ECG mismatch computation

The field of cardiac electrophysiology tries to abstract, describe and finally model the electrical characteristics of a heartbeat. With recent advances in cardiac electrophysiology, models have become more powerful and descriptive as ever. However, to advance to the field of inverse electrophysiological modeling, i.e. creating models from electrical measurements such as the ECG, the less investigated field of smoothness of the simulated ECGs w.r.t. model parameters need to be further explored. The present paper discusses smoothness in terms of the whole pipeline which describes how from physiological parameters, we arrive at the simulated ECG. Employing such a pipeline, we create a test-bench of a simplified idealized left ventricle model and demonstrate the most important factors for efficient inverse modeling through smooth cost functionals. Such knowledge will be important for designing and creating inverse models in future optimization and machine learning methods.

Current applications of hypnosis in the field of cardiac electrophysiology

With a growing acceptance of clinical hypnosis in medicine, new fields of application are being explored. Data from recent studies support the use of hypnosis for pain management during procedures, such as ablation of arrhythmias and implantation of subcutaneous implantable cardioverter defibrillators, management of preoperative anxiety and reduction of postoperative atrial fibrillation. The aim of this review article is to summarize the findings of investigations showing the application of hypnosis in the field of cardiac electrophysiology, to review the rationale for the efficacy of hypnosis in management of cardiac arrhythmias and to highlight possible future directions in clinical applications and scientific perspectives.

Data integration for the numerical simulation of cardiac electrophysiology.

The increasing availability of extensive and accurate clinical data is rapidly shaping cardiovascular care by improving the understanding of physiological and pathological mechanisms of the cardiovascular system and opening new frontiers in designing therapies and interventions. In this direction, mathematical and numerical models provide a complementary relevant tool, able not only to reproduce patient‐specific clinical indicators but also to predict and explore unseen scenarios. With this goal, clinical data are processed and provided as inputs to the mathematical model, which quantitatively describes the physical processes that occur in the cardiac tissue. In this paper, the process of integration of clinical data and mathematical models is discussed. Some challenges and contributions in the field of cardiac electrophysiology are reported.

Machine Learning in Arrhythmia and Electrophysiology.

Machine learning (ML), a branch of artificial intelligence, where machines learn from big data, is at the crest of a technological wave of change sweeping society. Cardiovascular medicine is at the forefront of many ML applications, and there is a significant effort to bring them into mainstream clinical practice. In the field of cardiac electrophysiology, ML applications have also seen a rapid growth and popularity, particularly the use of ML in the automatic interpretation of ECGs, which has been extensively covered in the literature. Much lesser known are the other aspects of ML application in cardiac electrophysiology and arrhythmias, such as those in basic science research on arrhythmia mechanisms, both experimental and computational; in the development of better techniques for mapping of cardiac electrical function; and in translational research related to arrhythmia management. In the current review, we examine comprehensively such ML applications as they match the scope of this journal. The current review is organized in 3 parts. The first provides an overview of general ML principles and methodologies that will afford readers of the necessary information on the subject, serving as the foundation for inviting further ML applications in arrhythmia research. The basic information we provide can serve as a guide on how one might design and conduct an ML study. The second part is a review of arrhythmia and electrophysiology studies in which ML has been utilized, highlighting the broad potential of ML approaches. For each subject, we outline comprehensively the general topics, while reviewing some of the research advances utilizing ML under the subject. Finally, we discuss the main challenges and the perspectives for ML-driven cardiac electrophysiology and arrhythmia research.

Gender representation at the Heart Rhythm Society Annual Scientific Sessions: A success story for diversity and inclusion

The Heart Rhythm Society (HRS) Annual Scientific Sessions is a renowned international conference in the field of cardiac electrophysiology. Since it is one of the largest conferences attended by electrophysiologists, evaluating whether the faculty of the meeting are representative of the field of clinical cardiac electrophysiology as a whole may provide an indication of the attention to, and success of, efforts at diversity.

Digital Health and the Care of the Patient With Arrhythmia: What Every Electrophysiologist Needs to Know.

The field of cardiac electrophysiology has been on the cutting edge of advanced digital technologies for many years. More recently, medical device development through traditional clinical trials has been supplemented by direct to consumer products with advancement of wearables and health care apps. The rapid growth of innovation along with the mega-data generated has created challenges and opportunities. This review summarizes the regulatory landscape, applications to clinical practice, opportunities for virtual clinical trials, the use of artificial intelligence to streamline and interpret data, and integration into the electronic medical records and medical practice. Preparation of the new generation of physicians, guidance and promotion by professional societies, and advancement of research in the interpretation and application of big data and the impact of digital technologies on health outcomes will help to advance the adoption and the future of digital health care.

A method for reduction of human ventricular action potential model

ABSTRACTMathematical modelling and computer simulations are important tools in the field of cardiac electrophysiology. High computational costs of complex models make them difficult to apply in large-scale simulations like tissue. Therefore, model reduction are of particular importance in heart studies. In this paper, we introduce a technique for simplification of ventricular cell(VC) complex models. By using this technique, starting with a complex model of human VC including 17state variables, we reduce the number of state variables to two. Our simplified model is compared with the original one via several electrophysiological features and computational efficiency. Results show that the reduced model has acceptable behaviours in single cell and one-dimensional simulation, moreover, is 55 times faster than the original one. As the presented method does not depend on the reference model, it may be applied to every cardiac cell models or each complex excitable dynamical systems with the same dynamics as VC.

A comparison of fourth-order operator splitting methods for cardiac simulations

Operator splitting methods constitute a powerful strategy to solve problems in the field of cardiac electrophysiology. In particular, it has been shown that operator splitting methods of order higher than two are more efficient than lower-order methods when solving problems involving simulations of the bidomain and monodomain models. An example of such problems is given by the Niederer problem, a well-defined benchmark in cardiac tissue electrophysiology. In this study, we present some fourth-order operator splitting methods, having real and complex coefficients, and compare their performance when applied to the Niederer benchmark as well as a variant with a stiffer cell model.

Open-Source Multiparametric Optocardiography

Since the 1970s fluorescence imaging has become a leading tool in the discovery of mechanisms of cardiac function and arrhythmias. Gradual improvements in fluorescent probes and multi-camera technology have increased the power of optical mapping and made a major impact on the field of cardiac electrophysiology. Tandem-lens optical mapping systems facilitated simultaneous recording of multiple parameters characterizing cardiac function. However, high cost and technological complexity restricted its proliferation to the wider biological community. We present here, an open-source solution for multiple-camera tandem-lens optical systems for multiparametric mapping of transmembrane potential, intracellular calcium dynamics and other parameters in intact mouse hearts and in rat heart slices. This 3D-printable hardware and Matlab-based RHYTHM 1.2 analysis software are distributed under an MIT open-source license. Rapid prototyping permits the development of inexpensive, customized systems with broad functionality, allowing wider application of this technology outside biomedical engineering laboratories.

Single Day Observational Experience at High Volume Ablation Programs: What is the Impact to Practicing Electrophysiologists?

Significant improvements in catheter technology, electro-anatomic (EA) mapping and techniques to reduce fluoroscopy during radiofrequency ablation (RFA) of atrial fibrillation (AF) are on-going.However, few educational opportunities are available post fellowship for Electrophysiologists (EPs) to understand and integrate them into their practice, preventing wide spread adoption. The impact of observational learning for adoption of new technologies and techniques in the field of cardiac electrophysiology has not been studied. We sought to report the impact of a visit to a high-volume center with experience in new technologies and fluoroscopy reductionto the clinical practice of EPs. Between 8/2014 and 10/2017 a total of 150 EPs visited 3 hospitals that perform a high volume of AF RFAs. EPs observed a minimum of 4 RFAs, primarily AF. AF RFAs were performed without fluoroscopy, using Carto 3 Version 4 (Biosense Webster) and intracardiac Echocardiography. There was ample interaction and discussion between hosting and visiting EP. 73 EPs (48.6% of visitors) completed an electronic survey after the visit. The majority reported a significant reduction in fluoroscopy (>50%) and procedure (>20%).68% adopted a rigorous workflow and reported an increase in their confidence level with intracardiac echo (79%), continuous mapping (52%) and the Visitag module (61%). Observational experience can have an immense impact on the clinical practice of EPs. Further effort should be devoted to such programs and to study in a more systematic way their ultimate impact on patient care.

From early beginnings to elaborate tools: contribution of German electrophysiology to the interventional treatment of cardiac arrhythmias : The German Cardiac Society welcomes ESC in Munich 2018.

Catheter ablation evolved from the early days of cardiac electrophysiology (EP), in which invasive electrophysiological studies were mainly a tool to find the correct diagnosis and to evaluate the most effective anti-arrhythmic drug for the patient. Today, catheter ablation is the most effective treatment option for patients suffering from supraventricular and ventricular arrhythmias. The understanding of cardiac arrhythmias and treatment strategies improved because of physicians and scientists from all over the world. The work of German cardiologists led to new achievements in the field of cardiac EP and catheter ablation. In this article, we summarize selective contributions of German EP centres in the field.

Early on the scene in the field of cardiac electrophysiology

Early on the scene in the field of cardiac electrophysiology

Role of Calcium-activated Potassium Channels in Atrial Fibrillation Pathophysiology and Therapy.

:Small-conductance Ca2+-activated potassium (SK) channels are relative newcomers within the field of cardiac electrophysiology. In recent years, an increased focus has been given to these channels because they might constitute a relatively atrial-selective target. This review will give a general introduction to SK channels followed by their proposed function in the heart under normal and pathophysiological conditions. It is revealed how antiarrhythmic effects can be obtained by SK channel inhibition in a number of species in situations of atrial fibrillation. On the contrary, the beneficial effects of SK channel inhibition in situations of heart failure are questionable and still needs investigation. The understanding of cardiac SK channels is rapidly increasing these years, and it is hoped that this will clarify whether SK channel inhibition has potential as a new anti–atrial fibrillation principle.

Ventricular tachycardia: mechanistic insights derived from adenosine.

A foundational concept in cardiac electrophysiology is that understanding the cellular mechanism of an arrhythmia provides essential insight for developing targeted therapeutic options. However, current clinical understanding of arrhythmogenic mechanisms other than re-entry is rudimentary, and the means by which to diagnose and differentiate these mechanisms are poorly defined. Grouping these mechanistic subtypes into broad and nonspecific categories, for example, non–re-entry or focal, further underscores our incomplete understanding of these arrhythmias. As the field of cardiac electrophysiology, like the rest of medicine, evolves toward the delivery of cell-based therapies, the need for a deeper understanding of clinical arrhythmia mechanisms and their arrhythmogenic cell lineages is apparent. One major difference between re-entrant and non– re-entrant ventricular tachycardia (VT) is that the electrophysiological substrate for re-entry is acquired during postnatal development and is due to anatomic insult (eg, ischemic heart disease or viral myocarditis), whereas the substrate for triggered activity is likely often acquired during embryological development, occurring independent of anatomic injury or structural heart disease.1,2 These dichotomous electrophysiological substrates, re-entry and non–re-entry, require tailored approaches to confirm diagnosis. In this review, we will elaborate on the development of a methodological approach for diagnosing non–re-entrant VT, which centers on the unique mechanism-specific properties of adenosine. This approach differs substantively from standard laboratory pacing methodologies used to validate the diagnosis of re-entrant arrhythmias and which are founded on the principles of entrainment.3 Adenosine is an endogenous nucleoside that exercises multiple regulatory functions that affect impulse generation and conduction, autonomic function, contractility, coronary vasodilation, and O2 supply–demand balance.4 Adenosine is rapidly inactivated as it is taken up by the cell through simple diffusion or a nucleoside transport system and is then deaminated to inosine or phosphorylated to adenosine monophosphate.5 The plasma half-life of adenosine is <1.5 s. …

Human cardiac systems electrophysiology and arrhythmogenesis: iteration of experiment and computation.

Human cardiac electrophysiology (EP) is a unique system for computational modelling at multiple scales. Due to the complexity of the cardiac excitation sequence, coordinated activity must occur from the single channel to the entire myocardial syncytium. Thus, sophisticated computational algorithms have been developed to investigate cardiac EP at the level of ion channels, cardiomyocytes, multicellular tissues, and the whole heart. Although understanding of each functional level will ultimately be important to thoroughly understand mechanisms of physiology and disease, cardiac arrhythmias are expressly the product of cardiac tissue-containing enough cardiomyocytes to sustain a reentrant loop of activation. In addition, several properties of cardiac cellular EP, that are critical for arrhythmogenesis, are significantly altered by cell-to-cell coupling. However, relevant human cardiac EP data, upon which to develop or validate models at all scales, has been lacking. Thus, over several years, we have developed a paradigm for multiscale human heart physiology investigation and have recovered and studied over 300 human hearts. We have generated a rich experimental dataset, from which we better understand mechanisms of arrhythmia in human and can improve models of human cardiac EP. In addition, in collaboration with computational physiologists, we are developing a database for the deposition of human heart experimental data, including thorough experimental documentation. We anticipate that accessibility to this human heart dataset will further human EP computational investigations, as well as encourage greater data transparency within the field of cardiac EP.

Alterations of field potentials in isotropic cardiomyocyte cell layers induced by multiple endogenous pacemakers under normal and hypothermal conditions.

The use of autonomous contracting randomly grown cardiomyocyte monolayers cultivated on microelectrode arrays (MEAs) represents an accepted experimental setting for preclinical experimental research in the field of cardiac electrophysiology. A dominant pacemaker forces a monolayer to adhere to a regular and synchronized contraction. Randomly distributed multiple pacemakers interfere with this dominant center, resulting in more or less frequent changes of propagation direction. This study aims to characterize the impact of changing propagation directions at single electrodes of the MEA on the four intrinsic parameters of registered field potentials (FPs) FPrise, FPMIN, FPpre, and FPdur and conduction velocity (CV) under normal and hypothermal conditions. Primary cultures of chicken cardiomyocytes (n = 18) were plated directly onto MEAs and FPs were recorded in a temperature range between 37 and 29°C. The number and spatiotemporal distribution of biological and artificial pacemakers of each cell layer inside and outside of the MEA registration area were evaluated using an algorithm developed in-house. In almost every second myocardial cell layer, interfering autonomous pacemakers were detected at stable temperatures, showing random spatial distributions with similar beating rates. Additionally, a temperature-dependent change of the dominant pacemaker center was observed in n = 16 experiments. A significant spread-direction-dependent variation of CV, FPrise, FPMIN, and FPpre up to 14% could be measured between different endogenous pacemakers. In conclusion, based on our results, disregarding the spatial origin of excitation may lead to misinterpretations and erroneous conclusions of FP parameters in the verification of research hypotheses in cellular electrocardiology.