Ischemia-induced ventricular proarrhythmia and cardiovascular autonomic dysreflexia after cardioneuroablation

Historical Perspective of the Cardiac Autonomic Nervous System

The contemporary history of the cardiac autonomic nervous system includes early descriptions of neuroanatomy in the 19th century, followed by an understanding of the physiologic determinants of neurocardiology in the 20th century. Neurology and cardiology preceded the arrival of clinical cardiac electrophysiology, a specialized field in medicine devoted to the diagnosis and treatment of cardiac arrhythmias. The rapid growth in pharmacology, ablation, pacing and defibrillation, associated with significant technological breakthroughs, have resulted in new opportunities for neuromodulation in the 21st century. Small changes in autonomic tone can potentially provide important therapeutic benefits for patients with cardiac and arrhythmia disorders.

Cardioneuroablation for Drug Refractory Vasovagal Syncope After COVID-19 Infection

Cardioneuroablation is a novel approach to treat patients with recurrent vasovagal syncope (VVS), targeting the ganglionated plexi around the atria and thus reducing the vagal input to the heart. This study reports a case of drug-refractory VVS after COVID-19 infection, successfully managed with cardioneuroablation.

Molecular and cellular neurocardiology in heart disease

This paper updates and builds on a previous White Paper in this journal that some of us contributed to concerning the molecular and cellular basis of cardiac neurobiology of heart disease. Here we focus on recent findings that underpin cardiac autonomic development, novel intracellular pathways and neuroplasticity. Throughout we highlight unanswered questions and areas of controversy. Whilst some neurochemical pathways are already demonstrating prognostic viability in patients with heart failure, we also discuss the opportunity to better understand sympathetic impairment by using patient specific stem cells that provides pathophysiological contextualization to study 'disease in a dish'. Novel imaging techniques and spatial transcriptomics are also facilitating a road map for target discovery of molecular pathways that may form a therapeutic opportunity to treat cardiac dysautonomia.

Cryoballoon cardioneuroablation: New electrophysiological insights

Background

Cardioneuroablation (CNA) targeting ganglionated plexi has shown promise in treating vasovagal syncope. Only radiofrequency ablation has been used to achieve this goal thus far.

Objective

The purpose of this study was to investigate the utility of cryoballoon ablation (CBA) of the pulmonary veins (PVs) as a potential simplified approach to CNA.

Methods

We report our observations of autonomic modulation in a series of 17 patients undergoing CBA for atrial fibrillation and our early experience using CBA of the PVs in 3 patients with malignant vagal syncope. In 17 patients undergoing CBA of AF, sinus cycle length was recorded intraprocedurally after ablation of individual PVs.

Results

The most pronounced shortening of the sinus cycle length was observed after isolation of the right upper PV, which was ablated last. Reduced sinus node recovery time and atrioventricular (AV) nodal effective refractory period were observed after CBA. Resting heart rate was elevated by 6-7 bpm after CBA and persisted during 12-month follow-up. CBA of the PVs was performed in 3 patients with recurrent vagal syncope mediated by sinus arrest (n = 2) and AV block (n = 1). In all patients, isolation of the right upper PV resulted in marked shortening of sinus cycle length. During follow-up of 178 ± 43 days (134-219 days), CNA resulted in abolition of pauses, bradycardia-related symptoms, and syncope in all patients.

Conclusion

CBA of the PVs (particularly the right upper PV) may be a predictable anatomic CNA approach in patients with refractory vagal syncope due to sinus arrest and/or AV block and may warrant systematic investigation as a tool to perform CNA.

Improvement in Atrioventricular Conduction Using Cardioneuroablation Performed Immediately after Pulmonary Vein Isolation

In patients with atrial fibrillation (AF) recurrences after pulmonary vein isolation (PVI), concomitant treatment using anti arrhythmic drugs (AADs) can lead to clinical success. However, patients with atrioventricular (AV) block may not be good candidates for concomitant AAD therapy due to the risk of further worsening of conduction abnormalities. Cardioneuroablation (CNA), as an adjunct to PVI, may offer a solution to this problem. We present a case of a 74-year-old male with paroxysmal AF and first degree AV block in whom CNA following PVI led to PR normalization. The presented case describes an example of CNA utilization in patients with AF undergoing PVI who have concomitant problems with AV conduction and shows that CNA can be sometimes useful in older patients with functional AV block.

The Intrinsic Cardiac Nervous System: From Pathophysiology to Therapeutic Implications

The cardiac autonomic nervous system (CANS) plays a pivotal role in cardiac homeostasis as well as in cardiac pathology. The first level of cardiac autonomic control, the intrinsic cardiac nervous system (ICNS), is located within the epicardial fat pads and is physically organized in ganglionated plexi (GPs). The ICNS system does not only contain parasympathetic cardiac efferent neurons, as long believed, but also afferent neurons and local circuit neurons. Thanks to its high degree of connectivity, combined with neuronal plasticity and memory capacity, the ICNS allows for a beat-to-beat control of all cardiac functions and responses as well as integration with extracardiac and higher centers for longer-term cardiovascular reflexes. The present review provides a detailed overview of the current knowledge of the bidirectional connection between the ICNS and the most studied cardiac pathologies/conditions (myocardial infarction, heart failure, arrhythmias and heart transplant) and the potential therapeutic implications. Indeed, GP modulation with efferent activity inhibition, differently achieved, has been studied for atrial fibrillation and functional bradyarrhythmias, while GP modulation with efferent activity stimulation has been evaluated for myocardial infarction, heart failure and ventricular arrhythmias. Electrical therapy has the unique potential to allow for both kinds of ICNS modulation while preserving the anatomical integrity of the system.