Clinical Correlates of Efficacy of Pyridostigmine in the Treatment of Orthostatic Hypotension.

Background: The cholinesterase inhibitor pyridostigmine is used to treat orthostatic hypotension by facilitating cholinergic neurotransmission in autonomic ganglia, thereby harnessing residual sympathetic tone to increase blood pressure (BP) preferentially in the upright posture. We hypothesized that less severe autonomic impairment was associated with greater pressor responses to pyridostigmine.

Methods: To identify predictors of pressor response, linear regression analyses between the effect of pyridostigmine on upright BP and markers of autonomic impairment were retrospectively conducted on 38 patients who had a medication trial with pyridostigmine (60 mg single dose).

Blood volume deficit in postural orthostatic tachycardia syndrome assessed by semiautomated carbon monoxide rebreathing.

Purpose: The semiautomated carbon monoxide (CO) rebreathing method has been introduced as a noninvasive and radiation-free blood volume estimation method. We tested whether the semiautomated CO rebreathing method can detect the blood volume deficit in postural orthostatic tachycardia syndrome (POTS). In addition, we explored the relationship between blood volume estimated from CO rebreathing and body impedance.

A Community-Based Trial of Commercially Available Compression Tights in Patients With Postural Orthostatic Tachycardia Syndrome.

Background: Compression garments reduce heart rate and symptoms in patients with postural orthostatic tachycardia syndrome in an acute laboratory setting. Patients taking medications controlling heart rate have less benefit from compression than those not on medications. The effectiveness of commercially available garments in a community-based setting, with and without medication use, is not known.

One Size Does Not Fit All: An Exploration of Compression Garment Use in Patients With Postural Orthostatic Tachycardia Syndrome.

Background: Postural orthostatic tachycardia syndrome (POTS) is a chronic form of orthostatic intolerance that primarily affects female patients. Despite the severity of POTS, there are no approved medications for use in patients with this disorder. Compression garments are a commonly prescribed nonpharmacological treatment, but little is known about the patient experience with compression.

Vagal stimulation ameliorates murine colitis by regulating SUMOylation.

Inflammatory bowel diseases (IBDs) are chronic debilitating conditions without cure, the etiologies of which are unknown, that shorten the lifespans of 7 million patients worldwide by nearly 10%. Here, we found that decreased autonomic parasympathetic tone resulted in increased IBD susceptibility and mortality in mouse models of disease. Conversely, vagal stimulation restored neuromodulation and ameliorated colitis by inhibiting the posttranslational modification SUMOylation through a mechanism independent of the canonical interleukin-10/α7 nicotinic cholinergic vagal pathway.

Reduced Stroke Volume and Brain Perfusion Drive Postural Hyperventilation in Postural Orthostatic Tachycardia Syndrome.

Postural hyperventilation has been implicated as a cause of postural orthostatic tachycardia syndrome (POTS), yet the precise mechanisms underlying the heightened breathing response remain unclear. This study challenges current hypotheses by revealing that exaggerated peripheral chemoreceptor activity is not the primary driver of postural hyperventilation. Instead, significant contributions from reduced stroke volume and compromised brain perfusion during orthostatic stress were identified.

The Role of the Autonomic Nervous System in Vasovagal Syncope.

The mechanism of vasovagal syncope (VVS) is multifaceted and involves a delicate balance within the autonomic nervous system (ANS). This review delves into the complex interplay between the ANS and VVS, elucidating the pivotal role that autonomic imbalance plays in the pathophysiology of this condition. Through a comprehensive exploration of the sympathetic and parasympathetic branches of the ANS, this review provides insights into the mechanisms that underlie VVS.

Postural orthostatic tachycardia syndrome in a Thai male patient.

Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous autonomic disorder. All patients have exaggerated tachycardia upon standing, but the pathophysiology may be diverse. We present a young adult Thai male with a chief complaint of palpitations while in an upright posture since childhood.

Assessment and management of exaggerated blood pressure response to standing and orthostatic hypertension: consensus statement by the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability.

Recent evidence suggests that an exaggerated blood pressure (BP) response to standing (ERTS) is associated with an increased risk of adverse outcomes, both in young and old individuals. In addition, ERTS has been shown to be an independent predictor of masked hypertension. In the vast majority of studies reporting on the prognostic value of orthostatic hypertension (OHT), the definition was based only on systolic office BP measurements.

Oral Delta-9-Tetrahydrocannabinol (THC) Increases Parasympathetic Activity and Supraspinal Conditioned Pain Modulation in Chronic Neuropathic Pain Male Patients: A Crossover, Double-Blind, Placebo-Controlled Trial.

Background: Disordered autonomic nervous system regulation and supraspinal pain inhibition have been repeatedly described in chronic pain. We aimed to explore the effects of δ-9-tetrahydrocannabinol (THC), an emerging treatment option, on autonomic nervous system and central pain modulation measures in patients with chronic pain.

Methods: Twelve male patients with chronic radicular neuropathic pain participated in a randomized, double-blind, crossover, placebo-controlled, single-administration trial.

Direct comparison of the diagnostic performance of growth differentiation factor 8 in pediatric versus adult heart failure.

Introduction: Growth differentiation factor 8 (GDF-8, myostatin) has been proposed for the management of adult heart failure (HF). Its potential role in pediatric HF patients is unknown. We sought to investigate its diagnostic performance in adult versus pediatric HF.

Cardiovascular autonomic dysfunction in post-COVID-19 syndrome: a major health-care burden.

Cardiovascular autonomic dysfunction (CVAD) is a malfunction of the cardiovascular system caused by deranged autonomic control of circulatory homeostasis. CVAD is an important component of post-COVID-19 syndrome, also termed long COVID, and might affect one-third of highly symptomatic patients with COVID-19. The effects of CVAD can be seen at both the whole-body level, with impairment of heart rate and blood pressure control, and in specific body regions, typically manifesting as microvascular dysfunction.

Randomized Trial Comparing SGLT2 Inhibition and Hydrochlorothiazide on Sympathetic Traffic in Type 2 Diabetes.

Introduction: Reductions in sympathetic nervous system activity may contribute to beneficial effects of sodium glucose cotransporter 2 (SGLT2) inhibition on cardiovascular outcomes. Therefore, we tested the hypothesis that SGLT2 inhibition with empagliflozin (Empa) lowers muscle sympathetic nerve activity (MSNA) in patients with type 2 diabetes mellitus (T2DM) compared with hydrochlorothiazide (HCT) to discern SGLT2-specific actions from responses to increased natriuresis.

Methods: We randomized patients with T2DM on metformin monotherapy to either 25 mg/d Empa ( = 20) or 25 mg/d HCT ( = 21) for 6 weeks in a parallel, double-blind fashion.

Adrenal gland response to adrenocorticotropic hormone is intact in patients with postural orthostatic tachycardia syndrome.

Background: Many patients with postural orthostatic tachycardia syndrome (POTS) are hypovolemic with plasma volume deficits of 10-30 %. Some also have low levels of aldosterone and diminished aldosterone-renin ratios despite elevations in angiotensin II, pointing to potential adrenal dysfunction. To assess adrenal gland responsiveness in POTS, we measured circulating levels of aldosterone and cortisol following adrenocorticotropin hormone (ACTH) stimulation.