Efficacy and Efficiency of Perioperative Stellate Ganglion Blocks in Cardiac Surgery: A Pilot Study

Neuromodulation therapy for atrial fibrillation

Atrial fibrillation has a multifactorial pathophysiology influenced by cardiac autonomic innervation. Both sympathetic and parasympathetic influences are profibrillatory. Innovative therapies targeting the neurocardiac axis include catheter ablation or pharmacologic suppression of ganglionated plexi, renal sympathetic denervation, low-level vagal stimulation, and stellate ganglion blockade. To date, these therapies have variable efficacy. As our understanding of atrial fibrillation and the cardiac nervous system expands, our approach to therapeutic neuromodulation will continue evolving for the benefit of those with AF.

The Heart Brain Team and Patient-Centered Management of Ischemic Stroke

The multifaceted connections between the heart and the brain have been extensively studied at the anatomy, pathophysiology, and clinical levels. Studies have suggested a vital role for both cardiologists and neurologists in the management of various cardiovascular and neurological disorders. However, a true heart-brain team-based approach remained confined to large, specialized centers. In this paper, we review the various intersection areas of cardiology and neurology with regard to ischemic stroke. We focus our discussion on the challenges and opportunity for a heart-team approach to stroke in the context of atrial fibrillation, carotid disease, and patent foramen ovale, and in the setting of strokes complicating transcatheter endovascular interventions.

Autonomic Neuromodulation for Atrial Fibrillation Following Cardiac Surgery: JACC Review Topic of the Week

Autonomic neuromodulation therapies (ANMTs) (ie, ganglionated plexus ablation, epicardial injections for temporary neurotoxicity, low-level vagus nerve stimulation [LL-VNS], stellate ganglion block, baroreceptor stimulation, spinal cord stimulation, and renal nerve denervation) constitute an emerging therapeutic approach for arrhythmias. Very little is known about ANMTs' preventive potential for postoperative atrial fibrillation (POAF) after cardiac surgery. The purpose of this review is to summarize and critically appraise the currently available evidence. Herein, the authors conducted a systematic review of 922 articles that yielded 7 randomized controlled trials. In the meta-analysis, ANMTs reduced POAF incidence (OR: 0.37; 95% CI: 0.25 to 0.55) and burden (mean difference [MD]: -3.51 hours; 95% CI: -6.64 to -0.38 hours), length of stay (MD: -0.82 days; 95% CI: -1.59 to -0.04 days), and interleukin-6 (MD: -79.92 pg/mL; 95% CI: -151.12 to -8.33 pg/mL), mainly attributed to LL-VNS and epicardial injections. Moving forward, these findings establish a base for future larger and comparative trials with ANMTs, to optimize and expand their use.

Neuromodulatory Approaches for Atrial Fibrillation Ablation

In this review, the authors describe evolving alternative strategies for the management of AF, focusing on non-invasive and percutaneous autonomic modulation. This modulation can be achieved – among other approaches – via tragus stimulation, renal denervation, cardiac afferent denervation, alcohol injection in the vein of Marshall, baroreceptor activation therapy and endocardial ganglionated plexi ablation. Although promising, these therapies are currently under investigation but could play a role in the treatment of AF in combination with conventional pulmonary vein isolation in the near future.

Neuroscientific therapies for atrial fibrillation

The cardiac autonomic nervous system (ANS) plays an integral role in normal cardiac physiology as well as in disease states that cause cardiac arrhythmias. The cardiac ANS, comprised of a complex neural hierarchy in a nested series of interacting feedback loops, regulates atrial electrophysiology and is itself susceptible to remodelling by atrial rhythm. In light of the challenges of treating atrial fibrillation (AF) with conventional pharmacologic and myoablative techniques, increasingly interest has begun to focus on targeting the cardiac neuraxis for AF. Strong evidence from animal models and clinical patients demonstrates that parasympathetic and sympathetic activity within this neuraxis may trigger AF, and the ANS may either induce atrial remodelling or undergo remodelling itself to serve as a substrate for AF. Multiple nexus points within the cardiac neuraxis are therapeutic targets, and neuroablative and neuromodulatory therapies for AF include ganglionated plexus ablation, epicardial botulinum toxin injection, vagal nerve (tragus) stimulation, renal denervation, stellate ganglion block/resection, baroreceptor activation therapy, and spinal cord stimulation. Pre-clinical and clinical studies on these modalities have had promising results and are reviewed here.

Ultrasound-guided stellate ganglion block alleviates stress responses and promotes recovery of gastrointestinal function in patients

BACKGROUND

This study aimed to investigate the effect of preoperative ultrasound-guided stellate ganglion block (SGB) on the perioperative stress responses and gastrointestinal functions of patients undergoing laparoscopic colorectal cancer surgery.

METHODS

A total of 60 colorectal cancer patients were enrolled in study and were randomized to be treated with or without SGB therapy. In the SGB group, patients were injected with 7 mL 0.5% ropivacaine in stellate ganglion under ultrasound guidance before anesthesia. Mean artery pressure (MAP), heart rate (HR), recovery of bowel sound and first exhaust, as well as levels of motilin, gastrin, norepinephrine, cortisol, interleukin-6 (IL-6) and C-reactive protein (CRP) were recorded at various time points.

RESULTS

26 patients in the SGB group and 27 patients in the control group were analyzed. No significant differences in MAP or HR were observed between the two groups before, during and after the surgery. SGB promoted recovery of gastrointestinal functions, as evidenced by earlier recovery of bowel sound and first exhaust, as well as increased motilin and gastrin levels. SGB also attenuated stress responses, as shown in reduced norepinephrine, cortisol, IL-6 and CRP levels.

CONCLUSIONS

SGB promotes the recovery of gastrointestinal functions and reduces stress responses of colorectal patients undergoing laparoscopic colorectal cancer surgery.

Neuromodulation for the Treatment of Heart Rhythm Disorders

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Derangement of autonomic nervous signaling is an important contributor to cardiac arrhythmogenesis.

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Modulation of autonomic nervous signaling holds significant promise for the prevention and treatment of cardiac arrhythmias.

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Further clinical investigation is necessary to establish the efficacy and safety of autonomic modulatory therapies in reducing cardiac arrhythmias.

There is an increasing recognition of the importance of interactions between the heart and the autonomic nervous system in the pathophysiology of arrhythmias. These interactions play a role in both the initiation and maintenance of arrhythmias and are important in both atrial and ventricular arrhythmia. Given the importance of the autonomic nervous system in the pathophysiology of arrhythmias, there has been notable effort in the field to improve existing therapies and pioneer additional interventions directed at cardiac-autonomic targets. The interventions are targeted to multiple and different anatomic targets across the neurocardiac axis. The purpose of this review is to provide an overview of the rationale for neuromodulation in the treatment of arrhythmias and to review the specific treatments under evaluation and development for the treatment of both atrial fibrillation and ventricular arrhythmias.