Left cardiac sympathetic denervation reduces skin sympathetic nerve activity in patients with long QT syndrome

Renal autonomic dynamics in hypertension: how can we evaluate sympathetic activity for renal denervation?

This review explores the various pathophysiological factors influencing antihypertensive effects, involving the regulation of vascular resistance, plasma volume, cardiac function, and the autonomic nervous system, emphasizing the interconnected processes regulating blood pressure (BP). The kidney's pivotal role in BP control and its potential contribution to hypertension is complicated but important to understand the effective mechanisms of renal denervation (RDN), which may be a promising treatment for resistant hypertension. Excessive stimulation of the sympathetic nervous system or the renin-angiotensin-aldosterone system (RAAS) can elevate BP through various physiological changes, contributing to chronic hypertension. Renal sympathetic efferent nerve activation leads to elevated norepinephrine levels and subsequent cascading effects on vasoconstriction, renin release, and sodium reabsorption. RDN reduces BP in resistant hypertension by potentially disrupting sensory afferent nerves, decreasing feedback activation to the central nervous system, and reducing efferent sympathetic nerve activity in the heart and other structures. RDN may also modulate central sympathetic outflow and inhibit renal renin-angiotensin system overactivation. While evidence for RDN efficacy in hypertension is increasing, accurate patient selection becomes crucial, considering complex interactions that vary among patients. This review also discusses methods to evaluate autonomic nerve activity from the golden standard to new potential examination for finding out optimization in stimulation parameters or rigorous patient selection based on appropriate biomarkers.

On animal pathophysiology-seeking models of takotsubo syndrome

The aim of this viewpoint/commentary on a recent contribution by the Gothenburg takotsubo syndrome (TTS) laboratory, in which the authors provide a comprehensive review/state of the art report on the animal models, currently employed in the elucidation of the pathophysiology of TTS, is to intensify the debate as to what constitutes a suitable TTS animal model with as promising as possible translational potential to the human TTS.

Life-Threatening Arrhythmias in Patients With Takotsubo Syndrome: Insights Into Pathophysiology and Treatment Innovations

Takotsubo syndrome (TTS) is a reversible form of acute myocardial injury due to a neurocardiogenic mechanism associated with a relevant risk for life-threatening ventricular arrhythmias, occurring in up to 25% of all patients and including both ventricular arrhythmias (especially) in the context of QT prolongation and atrial tachy- or bradyarrhythmias. The pathogenetic mechanisms of TTS-related arrhythmic complications are not completely understood, and there are no randomized clinical trials addressing the pharmacologic and nonpharmacologic management in this specific setting. In this narrative review, the authors provide an overview of the pathogenesis and the therapeutic management of arrhythmic complications in patients with TTS, along with the future perspectives and the remaining knowledge gaps in this field.

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.

Cardiac Sympathetic Denervation as a Treatment for Ventricular Arrhythmias Refractory to Conventional Treatment: A Case Series

Background

Ventricular arrhythmias are a leading cause of sudden death. The objective of this study was to characterise the results of patients with ventricular arrhythmias refractory to standard medical management, undergoing Video-assisted thoracoscopic cardiac sympathetic denervation (VAT-CSD) during 2012-2022 in Cali, Colombia.

Methods

This was an observational retrospective study, using the Institutional General Thoracic Surgery Database for patient identification and retrospectively reviewing the clinical charts for data description and analysis.

Results

Clinical records of 19 patients who underwent VAT-CSD for ventricular arrhythmia were analysed. The patients were predominantly male (73.7%) with an mean age of 62 years. Ischaemic heart disease was the main underlying condition (52.6%); all individuals had a diagnosis of heart failure, with comorbidities such as hypertension (63.1%), acute MI (57.8%) and diabetes (26.3%) also present. The procedure was performed bilaterally in 89.4% of cases and was successful with minimal perioperative complications. Postoperative follow-up showed improvement in symptoms, including a significant reduction in the number of ICD shocks and emergency department visits.

Conclusion

VAT-CSD is a viable, safe and palliative therapeutic option for patients with ventricular arrhythmias who have not responded to conventional treatments, achieving a significant decrease in symptoms with low mortality and perioperative complications.

The Mechanism of Cardiac Sympathetic Activity Assessment Methods: Current Knowledge

This review has summarized the methods currently available for cardiac sympathetic assessment in clinical or under research, with emphasis on the principles behind these methodologies. Heart rate variability (HRV) and other methods based on heart rate pattern analysis can reflect the dominance of sympathetic nerve to sinoatrial node function and indirectly show the average activity level of cardiac sympathetic nerve in a period of time. Sympathetic neurotransmitters play a key role of signal transduction after sympathetic nerve discharges. Plasma or local sympathetic neurotransmitter detection can mediately display sympathetic nerve activity. Given cardiac sympathetic nerve innervation, i.e., the distribution of stellate ganglion and its nerve fibers, stellate ganglion activity can be recorded either directly or subcutaneously, or through the surface of the skin using a neurophysiological approach. Stellate ganglion nerve activity (SGNA), subcutaneous nerve activity (SCNA), and skin sympathetic nerve activity (SKNA) can reflect immediate stellate ganglion discharge activity, i.e., cardiac sympathetic nerve activity. These cardiac sympathetic activity assessment methods are all based on the anatomy and physiology of the heart, especially the sympathetic innervation and the sympathetic regulation of the heart. Technological advances, discipline overlapping, and more understanding of the sympathetic innervation and sympathetic regulation of the heart will promote the development of cardiac sympathetic activity assessment methods.

[Congenital long QT syndrome]

Congenital long QT syndrome (LQTS) represents a group of heart diseases of genetic origin characterized by prolongation of the QT interval and an abnormal T wave on the electrocardiogram (ECG). They can have a dominant or recessive expression, the latter associated with sensorineural deafness. In both cases, its clinical presentation is associated with recurrent syncope and sudden death as a consequence of ventricular tachycardia, specifically Torsades de Pointes. Currently they are classified according to the specific genetic defect, being able to compromise around 16 genes and almost 2000 mutations. It should be suspected in individuals with related symptoms, electrocardiographic findings, and family history. Management is based on the reduction or elimination of symptoms, and concomitantly the prevention of sudden death (SD), in those children with congenital deafness, the management requires the application of the otolaryngologist specialist's own measures. The cardiovascular management implies the modification of lifestyles, mainly the prohibition of competitive sports, including swimming, avoiding exposure to loud sounds or triggers. The medications used include beta-blockers, and more rarely flecainide, ranozaline, and verapamil; invasive management consists of the implantation of a cardioverter defibrillator or even left sympathetic denervation, each with its own risks and benefits. In any of the cases, we must avoid the circumstances that increase the QT interval, as well as carry out the appropriate analysis of the benefits and risks of each possible invasive measure.

Video-thoracoscopic left cardiac sympathetic denervation for long-QT syndrome

BACKGROUND

Congenital long-QT syndrome represents the most common cardiac channelopathy and manifests as potentially lethal ventricular arrhythmias. Prevention strategies include beta-blockade pharmacotherapy, implantable cardioverter-defibrillators, and left cardiac sympathetic denervation, which can increase the threshold for ventricular fibrillation. Herein, we report our experience with video-assisted thoracoscopic left cardiac sympathetic denervation.

METHODS

We performed a retrospective review of the electronic medical records of all patients with congenital long-QT syndrome who underwent video-assisted thoracoscopic left cardiac sympathetic denervation at our institution.

RESULTS

From September 2009 to May 2016, 6 patients with a mean age of 30.5 years (range 20-47 years) underwent video-assisted thoracoscopic left cardiac sympathetic denervation for medically refractory long-QT syndrome. All patients had an uneventful recovery and were discharged 1-3 days after the operation. At a median follow-up of 14 months (range 12-60 months), 4 patients had no cardiac events while 2 experienced 1 episode of arrhythmic syncope and 1 episode of appropriate implantable cardioverter-defibrillator shock. Following surgery, the mean annual cardiac events in the study cohort decreased from 2.13 to 0.33 (p = 0.004) and the mean corrected QT interval reduced from 560 ms to 491 ms (p = 0.006).

CONCLUSIONS

Video-assisted thoracoscopic left cardiac sympathetic denervation is a safe and effective therapy in patients with congenital long-QT syndrome who continue to suffer from recurrent life-threatening arrhythmias or frequent implantable cardioverter-defibrillator discharges despite maximum tolerated doses of beta blockers.

Management of ventricular electrical storm: a contemporary appraisal

Ventricular electrical storm (VES) is a clinical scenario characterized by the clustering of multiple episodes of sustained ventricular arrhythmias (VA) over a short duration. Patients with VES are prone to psychological disorders, heart failure decompensation, and increased mortality. Studies have shown that 10–28% of the patients with secondary prevention ICDs can sustain VES. The triad of a susceptible electrophysiologic substrate, triggers, and autonomic dysregulation govern the pathogenesis of VES. The rate of VA, underlying ventricular function, and the presence of implantable cardioverter-defibrillator (ICD) determine the clinical presentation. A multi-faceted approach is often required for management consisting of acute hemodynamic stabilization, ICD reprogramming when appropriate, antiarrhythmic drug therapy, and sedation. Some patients may be eligible for catheter ablation, and autonomic modulation with thoracic epidural anesthesia, stellate ganglion block, or cardiac sympathetic denervation. Hemodynamically unstable patients may benefit from the use of left ventricular assist devices, and extracorporeal membrane oxygenation. Special scenarios such as idiopathic ventricular fibrillation, Brugada syndrome, Long and short QT syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, arrhythmogenic right ventricular cardiomyopathy, and cardiac sarcoidosis have been described as well. VES is a cardiac emergency that requires swift intervention. It is associated with poor short and long-term outcomes. A structured team-based management approach is paramount for the safe and effective treatment of this sick cohort.