Research Opportunities in Autonomic Neural Mechanisms of Cardiopulmonary Regulation: A Report From the National Heart, Lung, and Blood Institute and the National Institutes of Health Office of the Director Workshop

Precision sampling of discrete sites identified during in-vivo functional testing in the mammalian heart

Ventricular arrhythmias after myocardial infarction (MI) originate from discrete areas within the MI border zone (BZ), identified during functional electrophysiology tests. Accurate sampling of arrhythmogenic sites for ex-vivo study remains challenging, yet is critical to identify their tissue, cellular and molecular signature. In this study, we developed, validated, and applied a targeted sampling methodology based on individualized 3D prints of the human-sized pig heart. To this end, 3D anatomical models of the left ventricle were created from magnetic resonance imaging and fused with biplane fluoroscopy. Regions of interest for sampling were annotated on the anatomical models, from which we created a unique 3D printed cast with custom slits identifying the annotated regions for sampling. The methodology was validated by retrieving ablation lesions created at predefined locations on the anatomical model. We applied the methodology to sample arrhythmia-vulnerable regions after MI during adrenergic stimulation. A pipeline of imaging was developed to create a 3D high-resolution map of each sample, highlighting the complex interplay of cellular organization, and altered innervation in the BZ.

Cardiovascular disease in connective tissue disease-associated interstitial lung disease: A systematic review and meta-analysis of observational studies

OBJECTIVES

We performed a systematic review and meta-analysis to assess whether patients with connective tissue disease (CTD)-associated interstitial lung diseases (ILD) have an increased prevalence of cardiovascular (CV) disease and to validate associated risk factors.

METHODS

The PRISMA guidelines and PICO model were followed. We searched PubMed, Embase, Cochrane Library databases, Scopus, and Directory of Open Access Journals from inception to April 2024.

RESULTS

Thirteen studies comprising of 12,520 patients were included. Patients with CTD-ILD had a significantly increased risk of CV disease than patients with CTD (relative risk [RR] = 1.65, 95 % confidence interval [CI]: 1.41, 1.93), which are related to the proportion of men (P = 0.001) and the proportion of smokers (P = 0.045). Subgroup analysis found that patients with CTD-ILD had a higher risk of heart failure (RR = 2.84, 95 % CI: 1.50, 5.39), arrhythmia (RR = 1.55, 95 % CI: 1.22, 1.97) than patients with CTD. Another subgroup analysis showed that RA-ILD and SSc-ILD were associated with an increased risk of CV disease, but not IIM-ILD and MCTD-ILD (RA-ILD: RR = 2.19, 95 % CI: 1.27, 3.80; SSc-ILD: RR = 1.53, 95 % CI: 1.29, 1.82). Besides, patients with CTD-ILD had a higher prevalence of pulmonary arterial hypertension (RR = 2.48, 95 % CI: 1.69, 3.63) than patients with CTD.

CONCLUSIONS

Patients with CTD-ILD had a 1.65 times increased risk of CV than patients with CTD-non-ILD, with increased prevalence of heart failure and arrhythmia. The risk of CV disease in SSc-ILD and RA-ILD is increased and we should pay more attention to male smokers. In addition, compared with CTD patients, CTD-ILD patients had a higher risk of pulmonary arterial hypertension.

Autonomic Dysfunction Among Adult Survivors of Childhood Cancer in the St. Jude Lifetime Cohort Study

Background

The burden and functional significance of autonomic dysfunction among survivors of childhood cancer is unknown.

Objectives

We evaluated the prevalence, risk factors, and functional relevance of autonomic dysfunction in survivors.

Methods

We conducted a cross-sectional prospective evaluation of 1,041 adult survivors of childhood cancer treated with anthracyclines (31.1%), chest-directed radiation (13.5%), both (19.5%), or neither (35.9%), and 286 community control subjects enrolled in the SJLIFE (St Jude Lifetime Cohort Study). Four measures of autonomic dysfunction were evaluated: elevated resting heart rate, decreased heart rate reserve, decreased systolic blood pressure response to exercise, and delayed heart rate recovery. Logistic regression tested associations with impaired cardiorespiratory fitness (peak Vo2 < 80% predicted).

Results

Survivors (50.7% female) were 9.0 ± 5.8 years at cancer diagnosis and 35.5 ± 8.9 years at evaluation. Prevalence (survivors vs control subjects) of elevated resting heart rate (17.9% vs 7.0%), decreased heart rate reserve (21.7% vs 9.1%), decreased systolic blood pressure response to exercise (25.3% vs 12.6%), and delayed heart rate recovery (24.3% vs 10.6%) was more than 2-fold higher among survivors (P < 0.001 for all). Carboplatin (adjusted OR: 2.50; 95% CI: 1.42-4.40; P = 0.001), chest-directed radiation therapy (adjusted OR: 2.06; 95% CI: 1.52-2.75; P < 0.001), and cranial radiation (adjusted OR: 1.49; 95% CI: 1.08-2.05; P = 0.015) were associated with an increased likelihood of having ≥2 measures of autonomic dysfunction. Survivors with ≥2 measures of autonomic dysfunction were at increased risk for impaired cardiorespiratory fitness (adjusted OR: 2.71; 95% CI: 1.82-4.02; P < 0.001).

Conclusions

Survivors of childhood cancer manifest a higher prevalence of autonomic dysfunction associated with impaired cardiorespiratory fitness.

Vagal nerve stimulation in myocardial ischemia/reperfusion injury: from bench to bedside

The identification of acute cardioprotective strategies against myocardial ischemia/reperfusion (I/R) injury that can be applied in the catheterization room is currently an unmet clinical need and several interventions evaluated in the past at the pre-clinical level have failed in translation. Autonomic imbalance, sustained by an abnormal afferent signalling, is a key component of I/R injury. Accordingly, there is a strong rationale for neuromodulation strategies, aimed at reducing sympathetic activity and/or increasing vagal tone, in this setting. In this review we focus on cervical vagal nerve stimulation (cVNS) and on transcutaneous auricular vagus nerve stimulation (taVNS); the latest has the potential to overcome several of the issues of invasive cVNS, including the possibility of being used in an acute setting, while retaining its beneficial effects. First, we discuss the pathophysiology of I/R injury, that is mostly a consequence of the overproduction of reactive oxygen species. Second, we describe the functional anatomy of the parasympathetic branch of the autonomic nervous system and the most relevant principles of bioelectronic medicine applied to electrical vagal modulation, with a particular focus on taVNS. Then, we provide a detailed and comprehensive summary of the most relevant pre-clinical studies of invasive and non-invasive VNS that support its strong cardioprotective effect whenever there is an acute or chronic cardiac injury and specifically in the setting of myocardial I/R injury. The potential benefit in the emerging field of post cardiac arrest syndrome (PCAS) is also mentioned. Indeed, electrical cVNS has a strong anti-adrenergic, anti-inflammatory, antioxidants, anti-apoptotic and pro-angiogenic effect; most of the involved molecular pathways were already directly confirmed to take place at the cardiac level for taVNS. Pre-clinical data clearly show that the sooner VNS is applied, the better the outcome, with the possibility of a marked infarct size reduction and almost complete left ventricular reverse remodelling when VNS is applied immediately before and during reperfusion. Finally, we describe in detail the limited but very promising clinical experience of taVNS in I/R injury available so far.

Non-invasive Neuromodulation of Arrhythmias

The autonomic nervous system plays a central role in the pathogenesis of arrhythmias. Preclinical and clinical studies have demonstrated the therapeutic effect of neuromodulation at multiple anatomic targets across the neurocardiac axis for the treatment of arrhythmias. In this review, we discuss the rationale and clinical application of noninvasive neuromodulation techniques in treating arrhythmias and explore associated barriers and future directions, including optimization of stimulation parameters and patient selection.

Pathophysiologic Mechanisms in Cardiac Autonomic Nervous System and Arrhythmias

The autonomic nervous system, including the central nervous system and the cardiac plexus, maintains cardiac physiology. In diseased states, autonomic changes through neuronal remodeling generate electrical mechanisms of arrhythmia such as triggered activity or increased automaticity. This article will focus on the pathophysiological mechanisms of arrhythmia to highlight the role of the autonomic nervous system in disease and the related therapeutic interventions.

The National Sleep Research Resource: making data findable, accessible, interoperable, reusable and promoting sleep science

This paper presents a comprehensive overview of the National Sleep Research Resource (NSRR), a National Heart Lung and Blood Institute-supported repository developed to share data from clinical studies focused on the evaluation of sleep disorders. The NSRR addresses challenges presented by the heterogeneity of sleep-related data, leveraging innovative strategies to optimize the quality and accessibility of available datasets. It provides authorized users with secure centralized access to a large quantity of sleep-related data including polysomnography, actigraphy, demographics, patient-reported outcomes, and other data. In developing the NSRR, we have implemented data processing protocols that ensure de-identification and compliance with FAIR (Findable, Accessible, Interoperable, Reusable) principles. Heterogeneity stemming from intrinsic variation in the collection, annotation, definition, and interpretation of data has proven to be one of the primary obstacles to efficient sharing of datasets. Approaches employed by the NSRR to address this heterogeneity include (1) development of standardized sleep terminologies utilizing a compositional coding scheme, (2) specification of comprehensive metadata, (3) harmonization of commonly used variables, and (3) computational tools developed to standardize signal processing. We have also leveraged external resources to engineer a domain-specific approach to data harmonization. We describe the scope of data within the NSRR, its role in promoting sleep and circadian research through data sharing, and harmonization of large datasets and analytical tools. Finally, we identify opportunities for approaches for the field of sleep medicine to further support data standardization and sharing.

Circulating neuropeptide Y as a biomarker in postoperative atrial fibrillation cases administered off-pump coronary bypass Graft surgery

Background and aims

Postoperative atrial fibrillation (POAF) is considered the most prevalent irregular heart rhythm after heart surgery. The cardiac autonomic nervous system significantly affects POAF, and neuropeptide Y (NPY), an abundant neuropeptide in the cardiovascular system, is involved in this autonomic regulation. The current work aimed to examine the potential association of NPY with POAF in individuals administered isolated off-pump coronary artery bypass grafting.

Methods

From January 1 to May 31, 2020, we examined consecutive cases administered successful isolated off-pump coronary artery bypass grafting with no previously diagnosed atrial fibrillation (AF). Clinical characteristics and plasma samples were collected before surgery. NPY was quantified by enzyme-linked immunosorbent assay (ELISA) in peripheral blood, and POAF cases were identified through a 7-day Holter monitoring.

Results

Among 120 cases with no previously diagnosed AF, 33 (27.5 %) developed POAF during hospitalization. Median NPY levels were markedly elevated in the POAF group in comparison with the sinus rhythm group (31.72 vs. 27.95, P = 0.014). Multivariable logistic regression analysis revealed age (OR = 1.135, 95%CI 1.054-1.223; P = 0.001), left atrial size (OR = 1.136, 95%CI 1.004-1.285; P = 0.043), and NPY levels in peripheral blood (OR = 1.055, 95%CI 1.002-1.111; p = 0.041) independently predicted POAF. Additionally, NPY levels were positively correlated with high-frequency (HF) (r = 0.2774, P = 0.0022) and low-frequency (LF) (r = 0.2095, P = 0.0217) components of heart rate variability.

Conclusion

In summary, this study demonstrates an association between elevated NPY levels in peripheral blood before surgery and POAF occurrence.

Circadian Regulation of Cardiac Arrhythmias and Electrophysiology

Circadian rhythms in physiology and behavior are ≈24-hour biological cycles regulated by internal biological clocks (ie, circadian clocks) that optimize organismal homeostasis in response to predictable environmental changes. These clocks are present in virtually all cells in the body, including cardiomyocytes. Many decades ago, clinicians and researchers became interested in studying daily patterns of triggers for sudden cardiac death, the incidence of sudden cardiac death, and cardiac arrhythmias. This review highlights historical and contemporary studies examining the role of day/night rhythms in the timing of cardiovascular events, delves into changes in the timing of these events over the last few decades, and discusses cardiovascular disease-specific differences in the timing of cardiovascular events. The current understanding of the environmental, behavioral, and circadian mechanisms that regulate cardiac electrophysiology is examined with a focus on the circadian regulation of cardiac ion channels and ion channel regulatory genes. Understanding the contribution of environmental, behavioral, and circadian rhythms on arrhythmia susceptibility and the incidence of sudden cardiac death will be essential in developing future chronotherapies.

Mechanism of Ventricular Tachycardia Occurring in Chronic Myocardial Infarction Scar

Cardiac arrest is the leading cause of death in the more economically developed countries. Ventricular tachycardia associated with myocardial infarct is a prominent cause of cardiac arrest. Ventricular arrhythmias occur in 3 phases of infarction: during the ischemic event, during the healing phase, and after the scar matures. Mechanisms of arrhythmias in these phases are distinct. This review focuses on arrhythmia mechanisms for ventricular tachycardia in mature myocardial scar. Available data have shown that postinfarct ventricular tachycardia is a reentrant arrhythmia occurring in circuits found in the surviving myocardial strands that traverse the scar. Electrical conduction follows a zigzag course through that area. Conduction velocity is impaired by decreased gap junction density and impaired myocyte excitability. Enhanced sympathetic tone decreases action potential duration and increases sarcoplasmic reticular calcium leak and triggered activity. These elements of the ventricular tachycardia mechanism are found diffusely throughout scar. A distinct myocyte repolarization pattern is unique to the ventricular tachycardia circuit, setting up conditions for classical reentry. Our understanding of ventricular tachycardia mechanisms continues to evolve as new data become available. The ultimate use of this information would be the development of novel diagnostics and therapeutics to reliably identify at-risk patients and prevent their ventricular arrhythmias.

Anatomy and physiology of the autonomic nervous system: Implication on the choice of diagnostic/monitoring tools in 2023

The autonomic nervous system (ANS) harmoniously regulates all internal organic functions (heart rate, blood pressure, vasomotion, digestive tract motility, endocrinal secretions) and adapts them to the needs. It's the control of so-called vegetative functions, which allows homeostasis but also allostasis of our body. ANS is divided into two systems often understood as antagonistic and complementary: the sympathetic and the parasympathetic systems. However, we currently know of many situations of co-activation of the two systems. Long seen as acting through "reflex" control loops passing through the integration of peripheral information and the efferent response to the peripheral organ, more recent electrophysiological and brain functional imaging knowledge has been able to identify the essential role of the central autonomic network. This element complicates the understanding of the responses of the reflex loops classically used to identify and quantify dysautonomia. Finding the "ANS" tools best suited for the clinician in their daily practice is a challenge that we will attempt to address in this work.

A multiscale predictive digital twin for neurocardiac modulation

Cardiac function is tightly regulated by the autonomic nervous system (ANS). Activation of the sympathetic nervous system increases cardiac output by increasing heart rate and stroke volume, while parasympathetic nerve stimulation instantly slows heart rate. Importantly, imbalance in autonomic control of the heart has been implicated in the development of arrhythmias and heart failure. Understanding of the mechanisms and effects of autonomic stimulation is a major challenge because synapses in different regions of the heart result in multiple changes to heart function. For example, nerve synapses on the sinoatrial node (SAN) impact pacemaking, while synapses on contractile cells alter contraction and arrhythmia vulnerability. Here, we present a multiscale neurocardiac modelling and simulator tool that predicts the effect of efferent stimulation of the sympathetic and parasympathetic branches of the ANS on the cardiac SAN and ventricular myocardium. The model includes a layered representation of the ANS and reproduces firing properties measured experimentally. Model parameters are derived from experiments and atomistic simulations. The model is a first prototype of a digital twin that is applied to make predictions across all system scales, from subcellular signalling to pacemaker frequency to tissue level responses. We predict conditions under which autonomic imbalance induces proarrhythmia and can be modified to prevent or inhibit arrhythmia. In summary, the multiscale model constitutes a predictive digital twin framework to test and guide high-throughput prediction of novel neuromodulatory therapy. KEY POINTS: A multi-layered model representation of the autonomic nervous system that includes sympathetic and parasympathetic branches, each with sparse random intralayer connectivity, synaptic dynamics and conductance based integrate-and-fire neurons generates firing patterns in close agreement with experiment. A key feature of the neurocardiac computational model is the connection between the autonomic nervous system and both pacemaker and contractile cells, where modification to pacemaker frequency drives initiation of electrical signals in the contractile cells. We utilized atomic-scale molecular dynamics simulations to predict the association and dissociation rates of noradrenaline with the β-adrenergic receptor. Multiscale predictions demonstrate how autonomic imbalance may increase proclivity to arrhythmias or be used to terminate arrhythmias. The model serves as a first step towards a digital twin for predicting neuromodulation to prevent or reduce disease.

Circulating Neuropeptide Y May Be a Biomarker for Diagnosing Atrial Fibrillation

INTRODUCTION

Sympathetic nervous system disorder promotes atrial fibrillation (AF), and neuropeptide Y (NPY) is an important neurotransmitter. This study aimed to explore the predictive value of plasma NPY in patients with AF.

METHODS

Five hundred seventy-six patients were divided into AF (including paroxysmal and long-standing persistent AF; 360) and sinus rhythm (SR) groups (216). NPY level was detected using enzyme-linked immunosorbent assay, and NPY mRNA expression level was detected using quantitative polymerase chain reaction. Logistic regression was used to analyse the risk factors for AF; the correlations between blood NPY level and age, body mass index (BMI), left ventricular ejection fraction, left atrial diameter (LAD), and European Heart rate Association (EHRA) score in patients with AF were determined. The receiver operating characteristic (ROC) curve was utilised to predict AF.

RESULTS

Plasma NPY levels were found to be higher in patients with AF than in patients with SR and in patients with long-standing persistent AF than in patients with paroxysmal AF; blood NPY mRNA levels were higher in the paroxysmal and long-standing persistent AF groups compared to the SR group (p < 0.05). Increased age {odds ratio (OR) = 1.201 (95% confidence interval [CI]: 1.01, 1.427)} and high NPY [OR = 1.239 (95% CI: 1.022, 1.501)] were factors found to affect AF detrimentally. NPY was associated with BMI (r = 0.5856, p < 0.05), LAD (r = 0.4023, p < 0.05), and EHRA score (r = 0.898, p < 0.05). The ROC curve for the predictive value of plasma NPY levels for AF showed an area under the curve (AUC) value of 0.919 (p < 0.05), while that for long-standing persistent AF showed an AUC of 0.784 (p < 0.05).

CONCLUSION

Circulating NPY may be a promising molecular biomarker of AF.

Long-term changes in heart rate and electrical remodeling contribute to alternans formation in heart failure: a patient-specific in silico study

Individuals with chronic heart failure (CHF) have an increased risk of ventricular arrhythmias, which has been linked to pathological cellular remodeling and may also be mediated by changes in heart rate. Heart rate typically fluctuates on a timescale ranging from seconds to hours, termed heart rate variability (HRV). This variability is reduced in CHF, and this HRV reduction is associated with a greater risk for arrhythmias. Furthermore, variations in heart rate influence the formation of proarrhythmic alternans, a beat-to-beat alternation in the action potential duration (APD), or intracellular calcium (Ca). In this study, we investigate how long-term changes in heart rate and electrical remodeling associated with CHF influence alternans formation. We measure key statistical properties of the RR-interval sequences from ECGs of individuals with normal sinus rhythm (NSR) and CHF. Patient-specific RR-interval sequences and synthetic sequences (randomly generated to mimicking these statistical properties) are used as the pacing protocol for a discrete time-coupled map model that governs APD and intracellular Ca handling of a single cardiac myocyte, modified to account for pathological electrical remodeling in CHF. Patient-specific simulations show that beat-to-beat differences in APD vary temporally in both populations, with alternans formation more prevalent in CHF. Parameter studies using synthetic sequences demonstrate that increasing the autocorrelation time or mean RR-interval reduces APD alternations, whereas increasing the RR-interval standard deviation leads to higher alternans magnitudes. Importantly, we find that although both the CHF-associated changes in heart rate and electrical remodeling influence alternans formation, variations in heart rate may be more influential.NEW & NOTEWORTHY Using patient-specific data, we show that both the changes in heart rate and electrical remodeling associated with chronic heart failure influence the formation of proarrhythmic alternans in the heart.

Dynamics of ventilatory pattern variability and Cardioventilatory Coupling during systemic inflammation in rats

Introduction: Biometrics of common physiologic signals can reflect health status. We have developed analytics to measure the predictability of ventilatory pattern variability (VPV, Nonlinear Complexity Index (NLCI) that quantifies the predictability of a continuous waveform associated with inhalation and exhalation) and the cardioventilatory coupling (CVC, the tendency of the last heartbeat in expiration to occur at preferred latency before the next inspiration). We hypothesized that measures of VPV and CVC are sensitive to the development of endotoxemia, which evoke neuroinflammation. Methods: We implanted Sprague Dawley male rats with BP transducers to monitor arterial blood pressure (BP) and recorded ventilatory waveforms and BP simultaneously using whole-body plethysmography in conjunction with BP transducer receivers. After baseline (BSLN) recordings, we injected lipopolysaccharide (LPS, n = 8) or phosphate buffered saline (PBS, n =3) intraperitoneally on 3 consecutive days. We recorded for 4-6 h after the injection, chose 3 epochs from each hour and analyzed VPV and CVC as well as heart rate variability (HRV). Results: First, the responses to sepsis varied across rats, but within rats the repeated measures of NLCI, CVC, as well as respiratory frequency (fR), HR, BP and HRV had a low coefficient of variation, (<0.2) at each time point. Second, HR, fR, and NLCI increased from BSLN on Days 1-3; whereas CVC decreased on Days 2 and 3. In contrast, changes in BP and the relative low-(LF) and high-frequency (HF) of HRV were not significant. The coefficient of variation decreased from BSLN to Day 3, except for CVC. Interestingly, NLCI increased before fR in LPS-treated rats. Finally, we histologically confirmed lung injury, systemic inflammation via ELISA and the presence of the proinflammatory cytokine, IL-1β, with immunohistochemistry in the ponto-medullary respiratory nuclei. Discussion: Our findings support that NLCI reflects changes in the rat's health induced by systemic injection of LPS and reflected in increases in HR and fR. CVC decreased over the course to the experiment. We conclude that NLCI reflected the increase in predictability of the ventilatory waveform and (together with our previous work) may reflect action of inflammatory cytokines on the network generating respiration.

Exploring the Utility of Autonomic Nervous System Evaluation for Stroke Prognosis

Stroke is a major cause of functional disability and is increasing in frequency. Therefore, stroke prognosis must be both accurate and timely. Among other biomarkers, heart rate variability (HRV) is investigated in terms of prognostic accuracy within stroke patients. The literature research of two databases (MEDLINE and Scopus) is performed to trace all relevant studies published within the last decade addressing the potential utility of HRV for stroke prognosis. Only the full-text articles published in English are included. In total, forty-five articles have been traced and are included in the present review. The prognostic value of biomarkers of autonomic dysfunction (AD) in terms of mortality, neurological deterioration, and functional outcome appears to be within the range of known clinical variables, highlighting their utility as prognostic tools. Moreover, they may provide additional information regarding poststroke infections, depression, and cardiac adverse events. AD biomarkers have demonstrated their utility not only in the setting of acute ischemic stroke but also in transient ischemic attack, intracerebral hemorrhage, and traumatic brain injury, thus representing a promising prognostic tool whose clinical application may greatly facilitate individualized stroke care.

Oxidative stress associated with impaired autonomic control and severity of lung function in chronic obstructive pulmonary disease patients

Oxidative stress has been suggested to play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). This study aimed to investigate a link between malondialdehyde (MDA) levels, pulmonary function, and cardiac autonomic control in patients with COPD. Plasma levels of MDA, heart rate variability, and pulmonary function were measured in 50 clinically stable COPD patients and 50 normal male controls. COPD patients exhibited lower means of the standard deviations of all normal to normal (NN) intervals (SDNN), the square root of the mean of the sum of the squares of differences between adjacent NN intervals (RMSSD), and high frequency (HF). Nevertheless, they presented greater low frequency (LF) and low frequency/high frequency ratio (LF/HF ratio) in supine and head-up tilt positions than controls (P<0.001). More-over, a negative correlation between MDA levels with SDNN (P<0.001) and a positive correlation with LF (P<0.01) and LF/HF ratio (P<0.05) were observed in both positions. In COPD patients, plasma MDA levels were 2.3 times greater than controls (4.33±2.03 μM vs. 1.89±0.39 μM, P<0.001), and they were inversely correlated with forced vital capacity, forced expiratory volume in 1 sec, midexpiratory flow, and peak expiratory flow (P<0.001). Our findings suggest a potential role for oxidative stress in impaired cardiac autonomic control and clinical relevance of plasma MDA levels as a predictor of severity of COPD in COPD patients.

Potential Neuromodulation of the Cardio-Renal Syndrome

The cardio-renal syndrome (CRS) type 2 is defined as a progressive loss of renal function following a primary insult to the myocardium that may be either acute or chronic but is accompanied by a decline in myocardial pump performance. The treatment of patients with CRS is difficult, and the disease often progresses to end-stage renal disease that is refractory to conventional therapy. While a good deal of information is known concerning renal injury in the CRS, less is understood about how reflex control of renal sympathetic nerve activity affects this syndrome. In this review, we provide insight into the role of the renal nerves, both from the afferent or sensory side and from the efferent side, in mediating renal dysfunction in CRS. We discuss how interventions such as renal denervation and abrogation of systemic reflexes may be used to alleviate renal dysfunction in the setting of chronic heart failure. We specifically focus on a novel cardiac sensory reflex that is sensitized in heart failure and activates the sympathetic nervous system, especially outflow to the kidney. This so-called Cardiac Sympathetic Afferent Reflex (CSAR) can be ablated using the potent neurotoxin resinferitoxin due to the high expression of Transient Receptor Potential Vanilloid 1 (TRPV1) receptors. Following ablation of the CSAR, several markers of renal dysfunction are reversed in the post-myocardial infarction heart failure state. This review puts forth the novel idea of neuromodulation at the cardiac level in the treatment of CRS Type 2.

Metrics of high cofluctuation and entropy to describe control of cardiac function in the stellate ganglion

Stellate ganglia within the intrathoracic cardiac control system receive and integrate central, peripheral, and cardiopulmonary information to produce postganglionic cardiac sympathetic inputs. Pathological anatomical and structural remodeling occurs within the neurons of the stellate ganglion (SG) in the setting of heart failure (HF). A large proportion of SG neurons function as interneurons whose networking capabilities are largely unknown. Current therapies are limited to targeting sympathetic activity at the cardiac level or surgical interventions such as stellectomy, to treat HF. Future therapies that target the SG will require understanding of their networking capabilities to modify any pathological remodeling. We observe SG networking by examining cofluctuation and specificity of SG networked activity to cardiac cycle phases. We investigate network processing of cardiopulmonary transduction by SG neuronal populations in porcine with chronic pacing-induced HF and control subjects during extended in-vivo extracellular microelectrode recordings. We find that information processing and cardiac control in chronic HF by the SG, relative to controls, exhibits: (i) more frequent, short-lived, high magnitude cofluctuations, (ii) greater variation in neural specificity to cardiac cycles, and (iii) neural network activity and cardiac control linkage that depends on disease state and cofluctuation magnitude.

Implementing the National Heart, Lung, and Blood Institute's Strategic Vision in the Division of Cardiovascular Sciences-2022 Update

Spurred by the 2016 release of the National Heart, Lung, and Blood Institute's Strategic Vision, the Division of Cardiovascular Sciences developed its Strategic Vision Implementation Plan-a blueprint for reigniting the decline in cardiovascular disease (CVD) mortality rates, improving health equity, and accelerating translation of scientific discoveries into better cardiovascular health (CVH). The 6 scientific focus areas of the Strategic Vision Implementation Plan reflect the multifactorial nature of CVD and include (1) addressing social determinants of CVH and health inequities, (2) enhancing resilience, (3) promoting CVH and preventing CVD across the lifespan, (4) eliminating hypertension-related CVD, (5) reducing the burden of heart failure, and (6) preventing vascular dementia. This article presents an update of strategic vision implementation activities within Division of Cardiovascular Sciences. Overarching and cross-cutting themes include training the scientific workforce and engaging the extramural scientific community to stimulate transformative research in cardiovascular sciences. In partnership with other NIH Institutes, Federal agencies, industry, and the extramural research community, Division of Cardiovascular Sciences strategic vision implementation has stimulated development of numerous workshops and research funding opportunities. Strategic Vision Implementation Plan activities highlight innovative intervention modalities, interdisciplinary systems approaches to CVD reduction, a life course framework for CVH promotion and CVD prevention, and multi-pronged research strategies for combatting COVID-19. As new knowledge, technologies, and areas of scientific research emerge, Division of Cardiovascular Sciences will continue its thoughtful approach to strategic vision implementation, remaining poised to seize emerging opportunities and catalyze breakthroughs in cardiovascular sciences.