Brain-heart Axis Research Articles

Psychophysiological profile of ischemic patients according to their resting heart rate variability: one step closer to training individualization

Ischemic heart disease continues to be a major cause of morbidity and mortality around the world. Nowadays, research is focusing on the role of the brain-heart axis in autonomic nervous system balance. Resting heart rate variability (HRV) could help to identify the readiness of ischemic patients to achieve cardiac rehabilitation exercise stimulus in a safer manner. The objectives of the study were i) to analyze the resting HRV in ischemic cardiopathy, determining whether it was below or within its normal range, and ii) to identify the effect of the psychophysiological parameters of age, body mass index (BMI), blood pressure, cardiorespiratory fitness, and quality of life. This was a cross-sectional study of patients affected by ischemic cardiopathy. The patients were divided into the nonNormal-HRV or Normal-HRV group according to their normal resting HRV. The HRV temporal and frequency domains were recorded along with heart rate and blood pressure, BMI, cardiorespiratory fitness and auto-perception. The sample comprised men with an average age of 58.64±9.54 years. In total, 43.92% were below their normal resting-HRV range. They were older (P<.001, d=.856), had worse auto-perception (P<.001, d=.473), and higher systolic and lower diastolic blood pressure (P<.001, d=.446; P=.007, d=.29). HRV domains correlated directly (P<.05) with diastolic blood pressure and inversely with heart rate and age. The percentage of low resting-HRV scores in ischemic patients was higher than expected and was conditioned by age, blood pressure and heart rate. Moreover, the patients had worse auto-perception. All these factors should be considered to optimize cardiac rehabilitation programs.

Cardiac troponin elevation in intracerebral hemorrhage patients may rather reflect acute myocardial damage than acute myocardial infarction

Abstract Background Patients with acute ischemic stroke (AIS) and elevated cardiac troponin (cTn) have worse functional and mortality-related outcome. While elevated cTn is also frequently observed in patients with intracerebral hemorrhage (ICH), routine invasive coronary angiography should not be performed on these patients. Existing data on correlation of cTn elevation with patient outcome and the underlying causes in this specific patient group are sparse and largely heterogeneous. Purpose To investigate the clinical variables that predict cTn elevation in patients with ICH and the impact of cTn elevation on intrahospital mortality and functional outcome. Methods Our long-term Stroke Database was screened for ICH patients with high-sensitivity (hs) cTn measurement on admission (from 2015 onwards). Baseline characteristics, intrahospital mortality and functional outcome at discharge were compared between the groups with and without cTn elevation (hs-cTnI > vs. ≤0.045 µg/L). In addition, clinical variables with suspected significance for cTn elevation were analyzed for their predictive value. Results A total of 93/498 patients with ICH (18.7%; mean age 73±15 years, 53.8% females) were found to have a cTn elevation. Regarding etiology, 38.7% had an ICH occurring after AIS and 31.2% had a hypertensive ICH (each p=NS between groups). Patients with cTn elevation did not have a more pronounced cardiovascular risk profile and had a comparably low prevalence of coronary artery disease (CAD; 18.5%, p=NS). However, they were significantly less likely to be on oral anticoagulation at the time of the bleeding event (7.5 vs. 18.0%, p=0.013). CTn elevation had no negative impact on intrahospital mortality (21.5 vs. 20.5%, p=NS) or functional outcome at discharge (NIHSS score 10 (2; 26) vs. 9 (2; 22) points, mRS 5 (3; 5) vs. 5 (3; 5) points, each p=NS). Increasing NIHSS score on admission (p=0.021, OR 1.084 [1.012-1.160]), mRS ≥4 on admission (p=0.005, OR 2.207 [1.180-2.826]), infratentorial bleeding localization (p=0.034, OR 4.899 [1.132-21.207]) and aortic valve stenosis ≥ intermediate (p<0.001, OR 8.435 [2.429-29.294]) predicted cTn elevation. In contrast, severely impaired left ventricular function, CAD, atrial fibrillation, intraventricular hemorrhage or ICH occurring after AIS had no predictive value. Conclusions Almost one fifth of patients with ICH had an elevated cTn. Unlike in AIS, in ICH cTn elevation was not associated with a worse functional or mortality-related intrahospital outcome. In particular, severe functional impairment on admission, reflecting severe ICH, or infratentorial hemorrhage localization, thought to affect the autonomic nervous system, was predictive of concomitant myocardial cell damage. CAD was rare overall. This could indicate that the cTn elevation in connection with ICH is primarily related to acute myocardial damage along the brain-heart axis and less to myocardial infarction.

Investigating the effect of chronic stress, depressive-like pathology and cognitive impairments on acute myocardial infarction: sex-differentiated effects

Abstract Background/Introduction Depression is an independent risk factor for cardiovascular disease (CVD) with the prevalence rates being higher in women than men in the general population and among patients with CVD. Furthermore, an association between myocardial infarction and cognitive deficits has been proposed, but the pathophysiological mechanisms that are responsible for the brain-heart axis interaction have not been elucidated. Purpose The present study aims to: 1) evaluate sex differences in the effect of chronic unpredictable stress (CUS) on myocardial infarct size (IS) and 2) determine the molecular pathways affected by CUS in the heart. Methods Adult male and female C57BL/6J mice, were randomly divided into 4 groups (n=7/group): CON (Control, sham surgery), iCON (Control, myocardial ischemia/reperfusion (IR)), STR (Stress, sham surgery) and iSTR (Stress, IR). Mice were intermittently exposed to the CUS protocol consisted of 4 different stressors for 6 consecutive weeks. Locomotor activity (open field-OF), anxiety-like alterations (OF, elevated plus-maze-EPM test), depressive-like pathology (tail suspension test- TST) and cognition (Y-maze and Novel Object Recognition-NOR tests) were evaluated. After behavioral evaluation, the animals were subjected to 30 min I followed by 24 h of R or sham surgery and infarct size (IS) was determined via double Evan’s Blue and triphenyltetrazolium chloride staining. In a second series of experiments (n=5/group), the ischemic part of the myocardium was collected at 24h R and subjected to label free proteomic analysis, in order to identify alterations associated with the effect of CUS and IR. Results CUS induced anxiety, depressive-like pathology and cognitive deficits as indicated by the increased time spent in the closed arms of the EPM (p<0.005), the increased immobility time (TST, p<0.05), the reduced preference for the novel object (NOR, p<0.05), and the significant body weight reduction (p<0.001), in both male and female mice. CUS significantly increased IS (p<0.001) in both male and female mice. Proteomic analysis revealed that CUS affected the heart proteome, related to endoplasmic reticulum stress, mitochondrial damage and apoptosis, of both sexes in the absence of IR. Female mice were more susceptible to IR damage in absence of CUS with 248 significant genes (FDR<0.05) being deregulated mainly belonging to Keap-Nrf2-ARE signaling pathway, in contrast to 168 significant genes in male mice. In male mice, CUS exacerbated the IR injury proteome changes mainly related to induction of apoptosis and mitochondrial dysregulation (292 significant genes, FDR<0.05 for males vs 102 for females). Conclusions Chronic exposure to stress increases depressive-like pathology and cognitive deficits, leading to heart proteome alterations and increased IS in both sexes. Sex differences were observed indicating that the coexistence of CUS and IR render the male heart more susceptible to myocardial damage.

Practice improves older adults’ attentional control and prospective memory more than HD-tDCS: a randomized controlled trial

Frontal and parietal brain regions are involved in attentional control and prospective memory. It is debated, however, whether increased or decreased activity in those regions is beneficial for older adults’ task performance. We therefore aimed to systematically modulate activity in those regions using high-definition transcranial direct current stimulation. We included n = 106 healthy adults (60–75 years old, 58% female) in a randomized, double-blind, and sham-controlled study. We evaluated task performance twice in the laboratory and at home and additionally assessed heart rates. Participants received cathodal, anodal, or sham stimulation of the left or right inferior frontal lobe, or the right superior parietal lobe (1 mA for 20 min). Performance improved at visit two in laboratory tasks but declined in at-home tasks. Stimulation did not modulate performance change in laboratory tasks but prevented decline in at home-tasks. Heart rates increased at visit two but only when right inferior frontal lobe activity was inhibited. Repeating a task seems more beneficial than stimulation for laboratory tasks. This might be different for at-home tasks. Inhibiting right frontal brain function increases heart rates, possibly due to a modulation of the frontal-vagal brain-heart axis.

Exploring the genetic landscape of the brain-heart axis: A comprehensive analysis of pleiotropic effects between heart disease and psychiatric disorders

BackgroundThe genetic links between heart disease and psychiatric disorders are complex and not well understood. This study uses genome-wide association studies (GWAS) and advanced multilevel analyses to explore these connections. MethodsWe analyzed GWAS data from seven psychiatric disorders and five types of heart disease. Genetic correlations and overlaps were examined using linkage disequilibrium score regression (LDSC), high-definition likelihood (HDL), and Genetic analysis incorporating Pleiotropy and Annotation (GPA). Pleiotropic single-nucleotide variations (SNVs) were identified with pleiotropic analysis under the composite null hypothesis (PLACO) and annotated via Functional mapping and annotation of genetic associations (FUMA). Potential pleiotropic genes were identified using Multi-marker Analysis of GenoMic Annotation (MAGMA) and Summary data-based Mendelian Randomization (SMR). Mendelian randomization was employed to assess causal relationships. ResultsAmong 35 trait pairs, 32 showed significant genetic correlations or overlaps. PLACO identified 15,077 SNVs, with 287 recognized as pleiotropic loci and 20 colocalization sites. MAGMA and SMR revealed 75 potential pleiotropic genes involved in diverse pathways, including cancer, neurodevelopment, and cellular organization. Mouse Genome Informatics (MGI) queries provided evidence linking multiple genes to heart or psychiatric disorders. ConclusionsThis analysis reveals loci and genes with pleiotropic effects between heart disease and psychiatric disorders, highlighting shared biological pathways. These findings illuminate the genetic mechanisms underlying the brain-heart axis and suggest shared biological foundations for these conditions, offering potential targets for future prevention and treatment strategies.

The Brain-Heart Axis: An Umbrella Review on Impact of Psychiatric Disease on Incidence, Management, and Outlook of Cardiovascular Disease.

Psychiatric conditions, such as depression, anxiety, bipolar disorder, and schizophrenia, are increasingly recognized as significant risk factors for cardiovascular disease (CVD). This review systematically analyzes evidence from various databases to provide a comprehensive understanding of the impact of psychiatric illnesses on the incidence, management, and prognosis of CVD. Key findings suggest a bidirectional relationship between psychiatric disorders and CVD, indicating that mental health conditions can predispose individuals to CVD, while CVD can exacerbate or trigger psychiatric symptoms. The review explores the underlying mechanisms of these associations, including behavioral factors, stress responses, and medication side effects. It also examines the challenges in managing CVD patients with comorbid psychiatric conditions, emphasizing the importance for integrated care approaches. This review underscores the necessity of considering mental health as an integral component of cardiovascular care and calls for further research to develop tailored management strategies for these complex conditions, ultimately aiming to improve patient outcomes and quality of life. This comprehensive analysis provides valuable insights for future investigations and guides clinicians in optimizing care for patients with both psychiatric and cardiovascular conditions.

Impaired brain-heart axis in focal epilepsy: Alterations in information flow and implications for seizure dynamics.

This study delves into functional brain-heart interplay (BHI) dynamics during interictal periods before and after seizure events in focal epilepsy. Our analysis focuses on elucidating the causal interaction between cortical and autonomic nervous system (ANS) oscillations, employing electroencephalography and heart rate variability series. The dataset for this investigation comprises 47 seizure events from 14 independent subjects, obtained from the publicly available Siena Dataset. Our findings reveal an impaired brain-heart axis especially in the heart-to-brain functional direction. This is particularly evident in bottom-up oscillations originating from sympathovagal activity during the transition between preictal and postictal periods. These results indicate a pivotal role of the ANS in epilepsy dynamics. Notably, the brain-to-heart information flow targeting cardiac oscillations in the low-frequency band does not display significant changes. However, there are noteworthy changes in cortical oscillations, primarily originating in central regions, influencing heartbeat oscillations in the high-frequency band. Our study conceptualizes seizures as a state of hyperexcitability and a network disease affecting both cortical and peripheral neural dynamics. Our results pave the way for a deeper understanding of BHI in epilepsy, which holds promise for the development of advanced diagnostic and therapeutic approaches also based on bodily neural activity for individuals living with epilepsy.

Focus on ischaemic heart disease: prevention with colchicine, role of the brain-heart axis, new therapeutic targets for ischaemia-reperfusion injury.

Focus on ischaemic heart disease: prevention with colchicine, role of the brain-heart axis, new therapeutic targets for ischaemia-reperfusion injury.

Intracortical brain-heart interplay: An EEG model source study of sympathovagal changes.

The interplay between cerebral and cardiovascular activity, known as the functional brain-heart interplay (BHI), and its temporal dynamics, have been linked to a plethora of physiological and pathological processes. Various computational models of the brain-heart axis have been proposed to estimate BHI non-invasively by taking advantage of the time resolution offered by electroencephalograph (EEG) signals. However, investigations into the specific intracortical sources responsible for this interplay have been limited, which significantly hampers existing BHI studies. This study proposes an analytical modeling framework for estimating the BHI at the source-brain level. This analysis relies on the low-resolution electromagnetic tomography sources localization from scalp electrophysiological recordings. BHI is then quantified as the functional correlation between the intracortical sources and cardiovascular dynamics. Using this approach, we aimed to evaluate the reliability of BHI estimates derived from source-localized EEG signals as compared with prior findings from neuroimaging methods. The proposed approach is validated using an experimental dataset gathered from 32 healthy individuals who underwent standard sympathovagal elicitation using a cold pressor test. Additional resting state data from 34 healthy individuals has been analysed to assess robustness and reproducibility of the methodology. Experimental results not only confirmed previous findings on activation of brain structures affecting cardiac dynamics (e.g., insula, amygdala, hippocampus, and anterior and mid-cingulate cortices) but also provided insights into the anatomical bases of brain-heart axis. In particular, we show that the bidirectional activity of electrophysiological pathways of functional brain-heart communication increases during cold pressure with respect to resting state, mainly targeting neural oscillations in the , , and bands. The proposed approach offers new perspectives for the investigation of functional BHI that could also shed light on various pathophysiological conditions.

Imaging of the brain-heart axis: prognostic value in a European setting.

Increasing data suggest that stress-related neural activity (SNA) is associated with subsequent major adverse cardiovascular events (MACE) and may represent a therapeutic target. Current evidence is exclusively based on populations from the U.S. and Asia where limited information about cardiovascular disease risk was available. This study sought to investigate whether SNA imaging has clinical value in a well-characterized cohort of cardiovascular patients in Europe. In this single-centre study, a total of 963 patients (mean age 58.4 ± 16.1 years, 40.7% female) with known cardiovascular status, ranging from 'at-risk' to manifest disease, and without active cancer underwent 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography between 1 January 2005 and 31 August 2019. Stress-related neural activity was assessed with validated methods and relations between SNA and MACE (non-fatal stroke, non-fatal myocardial infarction, coronary revascularization, and cardiovascular death) or all-cause mortality by time-to-event analysis. Over a maximum follow-up of 17 years, 118 individuals (12.3%) experienced MACE, and 270 (28.0%) died. In univariate analyses, SNA significantly correlated with an increased risk of MACE (sub-distribution hazard ratio 1.52, 95% CI 1.05-2.19; P = .026) or death (hazard ratio 2.49, 95% CI 1.96-3.17; P < .001). In multivariable analyses, the association between SNA imaging and MACE was lost when details of the cardiovascular status were added to the models. Conversely, the relationship between SNA imaging and all-cause mortality persisted after multivariable adjustments. In a European patient cohort where cardiovascular status is known, SNA imaging is a robust and independent predictor of all-cause mortality, but its prognostic value for MACE is less evident. Further studies should define specific patient populations that might profit from SNA imaging.

Molecular Mechanisms of Ischemic Stroke: A Review Integrating Clinical Imaging and Therapeutic Perspectives.

Ischemic stroke poses a significant global health challenge, necessitating ongoing exploration of its pathophysiology and treatment strategies. This comprehensive review integrates various aspects of ischemic stroke research, emphasizing crucial mechanisms, therapeutic approaches, and the role of clinical imaging in disease management. It discusses the multifaceted role of Netrin-1, highlighting its potential in promoting neurovascular repair and mitigating post-stroke neurological decline. It also examines the impact of blood-brain barrier permeability on stroke outcomes and explores alternative therapeutic targets such as statins and sphingosine-1-phosphate signaling. Neurocardiology investigations underscore the contribution of cardiac factors to post-stroke mortality, emphasizing the importance of understanding the brain-heart axis for targeted interventions. Additionally, the review advocates for early reperfusion and neuroprotective agents to counter-time-dependent excitotoxicity and inflammation, aiming to preserve tissue viability. Advanced imaging techniques, including DWI, PI, and MR angiography, are discussed for their role in evaluating ischemic penumbra evolution and guiding therapeutic decisions. By integrating molecular insights with imaging modalities, this interdisciplinary approach enhances our understanding of ischemic stroke and offers promising avenues for future research and clinical interventions to improve patient outcomes.

Neurological Consequences of Cardiac Arrhythmias: Relationship Between Stroke, Cognitive Decline, and Heart Rhythm Disorders.

Cardiac arrhythmias are one of the most common disorders with high morbidity and mortality. The effect of cardiac arrhythmias on the brain is very pronounced due to the high sensitivity of the brain to oxygen and blood supply. This mortality is preventable by early diagnosis and treatment which improves the patient's quality of life. Intervening at the right time, post arrhythmia is significant in preventing deaths and improving patient outcomes. Multiple pathophysiological mechanisms are studied for the brain-axis implications, that have the potential to be targeted by novel therapies. In this review, we describe the pathophysiological mechanisms and recent advances in detail to understand the functional aspects of the brain-heart axis and neurological implications post-stroke, caused by cardiac disorders. This paper aims to discuss the current literature on the neurological consequences of cardiac arrhythmias and delve into a deeper understanding of the brain-heart axis, imbalances, and decline, with the aim of summarizing everything and all about the neurological consequences of cardiac arrhythmias.

Abstract 3625: Metabolic phenotypes of doxorubicin-induced cardiotoxicity in breast cancer patients

Abstract Background. Doxorubicin (DOX) is a highly effective chemotherapy agent that is commonly used in combination with other chemotherapy regimens to treat a wide range of cancers, including 32% of breast cancer (BC) cases. Although DOX has greatly increased the number of long-term cancer survivors, some DOX recipients have experienced DOX-induced cardiotoxicity (DIC). Currently, there are no validated markers that can predict the early development of DIC. Cardiac troponin released by cardiomyocytes has been used in non-clinical studies as a marker of myocardial injury; however, the false positive rates are high, and the predictive value on cardiotoxicity is limited. Therefore, novel biomarkers of DIC are urgently needed to identify patients who are at an increased risk, allowing early detection of the cardiotoxicity before it causes permanent cardiac damage. Methods. Untargeted metabolomics profiling was performed for plasma samples from a cohort of 28 breast cancer patients who developed abnormal cardiac function (ABN) and those who maintained normal cardiac function (NML). Blood samples were collected before, during, and after DOX-containing chemotherapy. Using both baseline observations and pre-post changes, machine-learning techniques were used to identify metabolite markers that can be used as early indicators of DIC in BC patients. Area under the receiver operating characteristic curve was reported to evaluate the performance of significant metabolites, and metabolite set enrichment analysis (MSEA) and network analysis were used to extrapolate known associations between metabolites and diseases. Results. Significant separation of plasma metabolomics profiles between ABN and NML patients at baseline was observed. From 1,124 metabolites, abundance of 59 metabolites were found to differ between ABN and NML patients at baseline. Across all patients, levels of 78 metabolites changed between baseline and after the 1st chemotherapy cycle. Of the 6 metabolites identified in both baseline and pre-post data, ABN patients had higher levels of dicarboxylic acids suberate and sebacate derived from ω-oxidation of fatty acids at baseline than NML patients. Enrichment analysis on the metabolites from the pre-post analysis suggested myocardio injury and carnitine palmitoyltransferase deficiency. Network analysis of metabolite-disease interactions further suggests potential impact on neurological health after chemotherapy. Conclusion. The metabolomics phenotype identified is indicative of impaired beta-oxidation at baseline for ABN patients. In addition, our findings suggest neurotoxic effect from DOX, implicating the potential brain-heart axis involved behind the cardiotoxicity phenotype. Citation Format: Se-Ran Jun, Katherine Wallis, Reid D. Landes, Valentina K. Todorova, L. Joseph Su, Sam Makhoul, Ping-Ching Hsu. Metabolic phenotypes of doxorubicin-induced cardiotoxicity in breast cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3625.

The brain-heart axis: Integrative analysis of the shared genetic etiology between neuropsychiatric disorders and cardiovascular disease

BackgroundMultiple observational studies have reported substantial comorbidity between neuropsychiatric disorders and cardiovascular disease (CVD), but the underlying mechanisms remain largely unknown. MethodsUsing GWAS summary datasets of 8 neuropsychiatric disorders and 6 cardiovascular diseases, an integrative analysis incorporating linkage-disequilibrium-score-regression (LDSC), Mendelian randomization (MR), functional mapping and annotation (FUMA), and functional enrichment analysis, was conducted to investigate shared genetic etiology of the brain-heart axis from the whole genome level, single-nucleotide polymorphism (SNP) level, gene level, and biological pathway level. ResultsIn LDSC analysis, 18 pairwise traits between neuropsychiatric disorders and CVD were identified with significant genetic overlaps, revealing extensive genome-wide genetic correlations. In bidirectional MR analysis, 19 pairwise traits were identified with significant causal relationships. Genetic liabilities to neuropsychiatric disorders, particularly attention-deficit hyperactivity disorder and major depressive disorder, conferred extensive significant causal effects on the risk of CVD, while hypertension seemed to be a risk factor for multiple neuropsychiatric disorders, with no significant heterogeneity or pleiotropy. In FUMA analysis, 13 shared independent significant SNPs and 887 overlapping protein-coding genes were detected between neuropsychiatric disorders and CVD. With GO and KEEG functional enrichment analysis, biological pathways of the brain-heart axis were highly concentrated in neurotransmitter synaptic transmission, lipid metabolism, aldosterone synthesis and secretion, glutathione metabolism, and MAPK signaling pathway. ConclusionExtensive genetic correlations and genetic overlaps between neuropsychiatric disorders and CVD were identified in this study, which might provide some new insights into the brain-heart axis and the therapeutic targets in clinical practice.

Central Autonomic Network and Heart Rate Variability in Premature Neonates

Introduction: The Central Autonomic Network (CAN) is a hierarchy of brain structures that collectively influence cardiac autonomic input, mediating the majority of brain-heart interactions, but has never been studied in premature neonates. In this study, we use heart rate variability (HRV), which has been described as the “primary output” of the CAN, and resting-state functional MRI (rsfMRI) to characterize brain-heart relationships in premature neonates. Methods: We studied premature neonates who underwent rsfMRI at term (37-week postmenstrual age or above) and had HRV data recorded during the same week of their MRI. HRV was derived from continuous electrocardiogram data during the week of the rsfMRI scan. For rsfMRI, a seed-based approach was used to define regions of interest (ROIs) pertinent to the CAN, and blood oxygen level-dependent signal was correlated between each ROI as a measure of functional connectivity. HRV was correlated with CAN connectivity (CANconn) for each region, and subgroup analysis was performed based on sex and clinical comorbidities. Results: Forty-seven premature neonates were included in this study, with a mean gestational age at birth of 28.1 +/− 2.6 weeks. Term CANconn was found to be significantly correlated with HRV in approximately one-fifth of CAN connections. Two distinct patterns emerged among these HRV-CANconn relationships. In the first, increased HRV was associated with stronger CANconn of limbic regions. In the second pattern, stronger CANconn at the precuneus was associated with impaired HRV maturation. These patterns were especially pronounced in male premature neonates. Conclusion: We report for the first time evidence of brain-heart relationships in premature neonates and an emerging CAN, most striking in male neonates, suggesting that the brain-heart axis may be more vulnerable in male premature neonates. Signatures in the heart rate may eventually become an important noninvasive tool to identify premature males at highest risk for neurodevelopmental impairment.

Stroke Related Brain-Heart Crosstalk: Pathophysiology, Clinical Implications, and Underlying Mechanisms.

The emergence of acute ischemic stroke (AIS) induced cardiovascular dysfunctions as a bidirectional interaction has gained paramount importance in understanding the intricate relationship between the brain and heart. Post AIS, the ensuing cardiovascular dysfunctions encompass a spectrum of complications, including heart attack, congestive heart failure, systolic or diastolic dysfunction, arrhythmias, electrocardiographic anomalies, hemodynamic instability, cardiac arrest, among others, all of which are correlated with adverse outcomes and mortality. Mounting evidence underscores the intimate crosstalk between the heart and the brain, facilitated by intricate physiological and neurohumoral complex networks. The primary pathophysiological mechanisms contributing to these severe cardiac complications involve the hypothalamic-pituitary-adrenal (HPA) axis, sympathetic and parasympathetic hyperactivity, immune and inflammatory responses, and gut dysbiosis, collectively shaping the stroke-related brain-heart axis. Ongoing research endeavors are concentrated on devising strategies to prevent AIS-induced cardiovascular dysfunctions. Notably, labetalol, nicardipine, and nitroprusside are recommended for hypertension control, while β-blockers are employed to avert chronic remodeling and address arrhythmias. However, despite these therapeutic interventions, therapeutic targets remain elusive, necessitating further investigations into this complex challenge. This review aims to delineate the state-of-the-art pathophysiological mechanisms in AIS through preclinical and clinical research, unraveling their intricate interplay within the brain-heart axis, and offering pragmatic suggestions for managing AIS-induced cardiovascular dysfunctions.

Integrative neuro-cardiovascular dynamics in response to test anxiety: A brain-heart axis study

Test anxiety (TA), a recognized form of social anxiety, is the most prominent cause of anxiety among students and, if left unmanaged, can escalate to psychiatric disorders. TA profoundly impacts both central and autonomic nervous systems, presenting as a dual manifestation of cognitive and autonomic components. While limited studies have explored the physiological underpinnings of TA, none have directly investigated the intricate interplay between the CNS and ANS in this context. In this study, we introduce a non-invasive, integrated neuro-cardiovascular approach to comprehensively characterize the physiological responses of 27 healthy subjects subjected to test anxiety induced via a simulated exam scenario. Our experimental findings highlight that an isolated analysis of electroencephalographic and heart rate variability data fails to capture the intricate information provided by a brain-heart axis assessment, which incorporates an analysis of the dynamic interaction between the brain and heart. With respect to resting state, the simulated examination induced a decrease in the neural control onto heartbeat dynamics at all frequencies, while the studying condition induced a decrease in the ascending heart-to-brain interplay at EEG oscillations up to 12Hz. This underscores the significance of adopting a multisystem perspective in understanding the complex and especially functional directional mechanisms underlying test anxiety.

The New Trends in Physiological and Pathological Actions of Ghrelin (Brain-Heart Axis) on the Heart and Cardiovascular System

Background: Ghrelin increased significantly the Left Ventriculus Eject Fraction and end-systolic volume after 30 minutes of intra-venous injection and without alterations heart rate and blood pressure. Ghrelin was discovered in 1999 as an only one 28 amino acid peptides (with octanoyl serine group) located on the short arm of chromosome 3 (position 3p25-26) having six exons, two are noncoding and four introns and encodes a 511 bp mRNA. Ghrelin is synthesized by the endocrine X/A-like cells located from the gastric fundus mucosa through the whole mucosa of the medium right vertical side of the stomach until to the 1 inch before anatomical pylorus. These cells are responsible to produced 80% of the whole ghrelin produced in the human body. Furthermore, other place of this production occurs at the hypothalamus, the pituitary, second portion of duodenum, pancreas, heart and other tissues. Bibliographic references also demonstrate the importance of ghrelin’s action in the main cardiovascular activities. Related to cardiovascular activities, ghrelin plays multitudinous beneficial and thereby help during cardiovascular diseases. Several studies demonstrated that ghrelin cause an anti-inflammatory activity by the inhibition of proinflammatory cytokines which can diminish inflammatory diseases in the heart, pericardium and specific innervations, for instance, vagus nerve and inhibited sympathetic nerves. Outcomes of this review emphasize these important actions of ghrelin. Methods: A systematic review of ghrelin activities over the heart and cardiovascular system with the inclusion of papers in review involved the physiological and physio pathological activities of ghrelin in vivo and in vitro studies. Results: Ghrelin is a natural tide with the growth hormone secretagogue (GHS) receptor (GHS-R) which cloned in 1996. The processes which generate this peptide and ghrelin-related peptides are transcriptional, translational and posttranslational. Homo and heterodimers of GHS-R and other yet unidentified receptors mediate the biological actions of acyl ghrelin and desacyl ghrelin. However, the main biological functions of ghrelin involve the secretion of growth hormone, stimulation of appetite and food intake at the hypothalamus, modulate acid secretion and motility, endocrine and exocrine pancreas secretion, blockaded insulin activity, heart functions and cardiovascular responses and other. Conclusion: One of the main occurrences in acute heart infarction is an increase activation of cardiac sympathetic nerve activity (CSNA) which is one of the causes of chronic cardiac dysfunction (CCD). Ghrelin is an effective for obtain a better cardiac function and by the suppression of renal sympathetic nerve activity which also have an important benefit to the acute myocardial infarction. Therefore, the physiological effects of ghrelin are very important to the body homeostasis even in the grave heart and cardiovascular diseases and in the immunological system.

Brain-Heart Axis: Brain-Derived Neurotrophic Factor and Cardiovascular Disease-A Review of Systematic Reviews.

The brain-heart axis is an intra- and bidirectional complex that links central nervous system dysfunction and cardiac dysfunction. In recent decades, brain-derived neurotrophic factor (BDNF) has emerged as a strategic molecule involved in both brain and cardiovascular disease (CVD). This systematic review of systematic reviews aimed to (1) identify and summarize the evidence for the BDNF genotype and BDNF concentration in CVD risk assessment, (2) evaluate the evidence for the use of BDNF as a biomarker of CVD recovery, and (3) evaluate rehabilitation approaches that can restore BDNF concentration. A comprehensive search strategy was developed using PRISMA. The risk of bias was assessed via ROBIS. Seven studies were identified, most of which aimed to evaluate the role of BDNF in stroke patients. Only two systematic reviews examined the association of BDNF concentration and polymorphism in CVDs other than stroke. The overall evidence showed that BDNF plays a fundamental role in assessing the risk of CVD occurrence, because lower BDNF concentrations and rs6265 polymorphism are often associated with CVD. Nevertheless, much work remains to be carried out in current research to investigate how BDNF is modulated in different cardiovascular diseases and in different populations.

Protein misfolding: an additional player in the stroke-heart syndrome

Abstract Background Patients suffering from acute ischemic stroke experience an increased risk of major adverse cardiovascular events, introducing the term of stroke-heart syndrome (SHS). Beside common risk factors, the so-called brain-heart axis represents a relevant yet not fully understood biological matrix driving this multi-organ condition. Together with inflammatory and neurohormonal signals, protein misfolding appears as an additional component of this matrix. In fact, previous studies employing animal models of cerebral ischemia identified wrongly arranged toxic proteins (oligomers). In light of the spreading capabilities of such proteins, we questioned whether protein misfolding plays a role in the SHS. Purpose The purpose of this study is to investigate the occurrence of protein misfolding in the post-stroke cardiac dysfunction by assessing presence, origin, localization and routes of oligomers in the heart following an acute ischemic stroke. Its biological and physiological relevance are evaluated by in vivo and in vitro assessments of the myocardium. Methods Acute cerebral ischemic injury was induced in the mouse by left transient middle cerebral artery occlusion for 45 minutes followed by 48 hours of reperfusion in 3-4 month-old C57BL/6J wild type males. Sham operated littermate mice were used as controls. Forty-eight hours after acute cerebral ischemia, cardiac function was evaluated by electrocardiography and compared to pre-operative assessment. Organs were harvested after the abovementioned assessment for the localization and semi-quantification of oligomers in heart and lymph nodes. Furthermore, biological responses related to protein homeostasis in the myocardium were assessed on mRNA and protein levels. Results Our preliminary results show that acute ischemic stroke is associated with an increased presence of oligomers in the heart. In addition, higher levels of oligomers were detected in axillary lymph nodes isolated from stroke mice, suggesting a possible route of oligomers spreading (Fig 1A). Correlating with oligomers occurrence, molecular analyses showed significant upregulation of the inositol-requiring enzyme 1 (IRE1), and catalase at mRNA level (Fig 1B). On the other hand, the expression of the 78-kDa glucose-regulated protein (GRP78), and catalase significantly decreased at protein level, indicating impaired myocardial protein quality control and oxidative stress after acute ischemic stroke (Fig 1C). Stroke-induced cardiac dysfunction was presented by decreased heart weight to tibia length ratio as well as slower and irregular heart rhythm suggesting signs of arrhythmia (Fig 2). Conclusions Acute ischemic stroke is associated with an increased oligomers occurrence in the myocardium and ultimately correlates with altered cardiac resistance against proteotoxicity. Further experiments will be conducted in order to elucidate the role of oligomers as active players or bystanders in the stroke-heart syndrome.