Ganglionic Plexus Ablation: A Step-by-step Guide for Electrophysiologists and Review of Modalities for Neuromodulation for the Management of Atrial Fibrillation

Neuromodulation for Vasovagal Syncope and Bradyarrhythmias

Catheter-based neuromodulation of intrinsic cardiac autonomic nervous system is increasingly being used to improve outcomes in patients with vasovagal syncope and bradyarrhythmias caused by vagal overactivity. However, there is still no consensus for patient selection, technical steps, and procedural end points. This review takes the reader on a practical exploration of neuromodulation for bradyarrhythmias, concentrating on the critical aspects of proper patient selection, evidence-based insights, and anatomic intricacies within the intrinsic cardiac autonomic nervous system. Also discussed are different mapping techniques and outcome measures. Future directions to optimize the utilization of this technique in clinical practice are highlighted.

Atrial fibrillation considerations in the fourth trimester (postpartum period)

Postpartum atrial fibrillation is an uncommon but increasingly prevalent tachyarrhythmia that merits special management considerations with regards to the safety and efficacy of anticoagulation, rate and rhythm control as well as drug exposure to infants throughout breastfeeding. In this state-of-the-art review, we examine the demographics of postpartum atrial fibrillation with its associated risk factors, describe the safety of commonly used atrial fibrillation therapies, and discuss important considerations for women considering subsequent pregnancies.

Autonomic neuronal modulations in cardiac arrhythmias: Current concepts and emerging therapies

The pathophysiology of atrial fibrillation and ventricular tachycardia that result in cardiac arrhythmias is related to the sustained complicated mechanisms of the autonomic nervous system. Atrial fibrillation is when the heart beats irregularly, and ventricular arrhythmias are rapid and inconsistent heart rhythms, which involves many factors including the autonomic nervous system. It's a complex topic that requires careful exploration. Cultivation of speculative knowledge on atrial fibrillation; the irregular rhythm of the heart and ventricular arrhythmias; rapid oscillating waves resulting from mistakenly inconsistent P waves, and the inclusion of an autonomic nervous system is an inconceivable approach toward clinical intricacies. Autonomic modulation, therefore, acquires new expansions and conceptions of appealing therapeutic intelligence to prevent cardiac arrhythmia. Notably, autonomic modulation uses the neural tissue's flexibility to cause remodeling and, hence, provide therapeutic effects. In addition, autonomic modulation techniques included stimulation of the vagus nerve and tragus, renal denervation, cardiac sympathetic denervation, and baroreceptor activation treatment. Strong preclinical evidence and early human studies support the annihilation of cardiac arrhythmias by sympathetic and parasympathetic systems to transmigrate the cardiac myocytes and myocardium as efficient determinants at the cellular and physiological levels. However, the goal of this study is to draw attention to these promising early pre-clinical and clinical arrhythmia treatment options that use autonomic modulation as a therapeutic modality to conquer the troublesome process of irregular heart movements. Additionally, we provide a summary of the numerous techniques for measuring autonomic tone such as heart rate oscillations and its association with cutaneous sympathetic nerve activity appear to be substitute indicators and predictors of the outcome of treatment.

A case report of cardiac neuromodulation in a young patient with a third-degree atrioventricular block

Background

There are some functional bradyarrhythmias that are caused by a dysregulation of the autonomic nervous system, for which a therapeutic strategy of cardioneuroablation (CNA) is conceivable.

Case summary

In this study, we report the case of a 19-year-old woman with a non-congenital third-degree atrioventricular block (AVB), symptomatic for lipothymia and dyspnea caused by mild exertion. She had a structurally normal heart and no other comorbidities. The atropine test and the exercise stress test documented a sinus tachycardia at 190 bpm with a 2:1 AVB, a narrow QRS, and an atrioventricular conduction of 1:1 until reaching a sinus rhythm rate of 90 bpm. She underwent the CNA procedure, which targeted the inferior paraseptal ganglion plexus, with a gradual change in the ECG levels recorded during the radiofrequency delivery from a third-degree AVB to a first-degree AVB. After the procedure, we observed a complete regression of the third-degree AVB, with evidence of only a first-degree AVB and a complete regression of symptoms until the 6-month follow-up.

Conclusions

Although not yet included in current guidelines, the CNA procedure could be used to treat AV node dysfunction in young subjects, as it could represent an alternative to pacemaker implantation. However, more randomized studies are needed to assess the long-term efficacy of this promising technique.

Overcoming Uncertainties in Electrogram-Based Atrial Fibrillation Mapping: A Review

In clinical rhythmology, intracardiac bipolar electrograms (EGMs) play a critical role in investigating the triggers and substrates inducing and perpetuating atrial fibrillation (AF). However, the interpretation of bipolar EGMs is ambiguous due to several aspects of electrodes, mapping algorithms and wave propagation dynamics, so it requires several variables to describe the effects of these uncertainties on EGM analysis. In this narrative review, we critically evaluate the potential impact of such uncertainties on the design of cardiac mapping tools on AF-related substrate characterization. Literature suggest uncertainties are due to several variables, including the wave propagation vector, the wave's incidence angle, inter-electrode spacing, electrode size and shape, and tissue contact. The preprocessing of the EGM signals and mapping density will impact the electro-anatomical representation and the features extracted from the local electrical activities. The superposition of multiple waves further complicates EGM interpretation. The inclusion of these uncertainties is a nontrivial problem but their consideration will yield a better interpretation of the intra-atrial dynamics in local activation patterns. From a translational perspective, this review provides a concise but complete overview of the critical variables for developing more precise cardiac mapping tools.

Cardioneuroablation Using Epicardial Pulsed Field Ablation for the Treatment of Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting millions of people worldwide. The cardiac autonomic nervous system (ANS) is widely recognized as playing a key role in both the initiation and propagation of AF. This paper reviews the background and development of a unique cardioneuroablation technique for the modulation of the cardiac ANS as a potential treatment for AF. The treatment uses pulsed electric field energy to selectively electroporate ANS structures on the epicardial surface of the heart. Insights from in vitro studies and electric field models are presented as well as data from both pre-clinical and early clinical studies.