1,720,964 research outputs found
Antibodies against Angiotensin II Type 1 and Endothelin 1 Type A Receptors in Cardiovascular Pathologies
Full text linkAngiotensin II receptor type 1 (AT1R) and endothelin-1 receptor type A (ETAR) are G-protein-coupled receptors (GPCRs) expressed on the surface of a great variety of cells: immune cells, vascular smooth cells, endothelial cells, and fibroblasts express ETAR and AT1R, which are activated by endothelin 1 (ET1) and angiotensin II (AngII), respectively. Certain autoantibodies are specific for these receptors and can regulate their function, thus being known as functional autoantibodies. The function of these antibodies is similar to that of natural ligands, and it involves not only vasoconstriction, but also the secretion of proinflammatory cytokines (such as interleukin-6 (IL6), IL8 and TNF-α), collagen production by fibroblasts, and reactive oxygen species (ROS) release by fibroblasts and neutrophils. The role of autoantibodies against AT1R and ETAR (AT1R-AAs and ETAR-AAs, respectively) is well described in the pathogenesis of many medical conditions (e.g., systemic sclerosis (SSc) and SSc-associated pulmonary hypertension, cystic fibrosis, and allograft dysfunction), but their implications in cardiovascular diseases are still unclear. This review summarizes the current evidence regarding the effects of AT1R-AAs and ETAR-AAs in cardiovascular pathologies, highlighting their roles in heart transplantation and mechanical circulatory support, preeclampsia, and acute coronary syndromes
Inherited and acquired rhythm disturbances in sick sinus syndrome, brugada syndrome, and atrial fibrillation: Lessons from preclinical modeling
Full text linkRhythm disturbances are life-threatening cardiovascular diseases, accounting for many deaths annually worldwide. Abnormal electrical activity might arise in a structurally normal heart in response to specific triggers or as a consequence of cardiac tissue alterations, in both cases with catastrophic consequences on heart global functioning. Preclinical modeling by recapitulating human pathophysiology of rhythm disturbances is fundamental to increase the comprehension of these diseases and propose effective strategies for their prevention, diagnosis, and clinical management. In silico, in vivo, and in vitro models found variable application to dissect many congenital and acquired rhythm disturbances. In the copious list of rhythm disturbances, diseases of the conduction system, as sick sinus syndrome, Brugada syndrome, and atrial fibrillation, have found extensive preclinical modeling. In addition, the electrical remodeling as a result of other cardiovascular diseases has also been investigated in models of hypertrophic cardiomyopathy, cardiac fibrosis, as well as arrhythmias induced by other non-cardiac pathologies, stress, and drug cardiotoxicity. This review aims to offer a critical overview on the effective ability of in silico bioinformatic tools, in vivo animal studies, in vitro models to provide insights on human heart rhythm pathophysiology in case of sick sinus syndrome, Brugada syndrome, and atrial fibrillation and advance their safe and successful translation into the cardiology arena
Role of coronary microvascular dysfunction in heart failure with preserved ejection fraction
Full text linkHeart failure with preserved ejection fraction (HFpEF) is one of the greatest unmet needs in modern medicine. The lack of an appropriate therapy may reflect the lack of an accurate comprehension of its pathophysiology. Coronary microvascular rarefaction in HFpEF was first hypothesized in an autopsy study that showed how HFpEF patients had lower microvascular density and more myocardial fibrosis than control subjects. This was later confirmed in vivo when it was noted that HFpEF is associated with reduced myocardial flow reserve (MFR) at single photon emission computed tomography (SPECT) and that coronary microvascular dysfunction may play a role in HFpEF disease processes. HFpEF patients were found to have lower coronary flow reserve (CFR) and a higher index of microvascular resistance (IMR). What is the cause of microvascular dysfunction? In 2013, a new paradigm for the pathogenesis of HFpEF has been proposed. It has been postulated that the presence of a proinflammatory state leads to coronary microvascular endothelial inflammation and reduced nitric oxide bioavailability, which ultimately results in heart failure. Recently, it has also been noted that inflammation is the main driver of HFpEF, but via an increase in inducible nitric oxide synthase (iNOS) resulting in a decrease in unfolded protein response. This review summarizes the current evidence on the etiology of coronary microvascular dysfunction in HFpEF, focusing on the role of inflammation and its possible prevention and therapy
Antibodies against angiotensin II type 1 and endothelin-1 type A receptors are associated with microvascular obstruction after revascularized ST-elevation myocardial infarction
Full text linkEARLY IDENTIFICATION OF VENTRICULAR DYSFUNCTION IN JUVENILE SYSTEMIC SCLEROSIS BY SPECKLE TRACKING ECHOCARDIOGRAPHY
No full textSpeckle Tracking Echocardiography, a Sensitive Tool to Detect Early Cardiac Dysfunctions in Juvenile Systemic Sclerosis
No full textCoronary microvascular dysfunction in autoimmune rheumatic diseases: beyond coronary flow velocity reserve
Full text linkAutoimmune rheumatic diseases (ARDs) are a heterogeneous group of disorders characterized by an inappropriate immune reactivity against different body tissues. Patients affected by ARDs present increased cardiovascular morbidity and mortality, which significantly impacts long-term prognosis. Endothelial dysfunction, inflammation, oxidative stress, and autoimmunity are strictly involved in atherosclerosis progression and coronary microvascular dysfunction (CMD), both of which contribute to increased cardiovascular risk. CMD represents the inability of the coronary microvasculature to respond with vasodilation to increased cardiac metabolic demands and can be assessed by non-invasive and invasive imaging tests. Coronary flow velocity reserve assessed by echocardiography has been demonstrated to accurately identify ARDs patients with CMD. However, stress cardiac magnetic resonance (CMR) accurately assesses myocardial ischemia, perfusion, and viability in ARDs patients. The myocardial perfusion reserve index (MPRI) is a robust semiquantitative imaging marker that represents the vasodilatory capacity of the coronary microcirculation in response to a vasodilator stress. In the absence of significant coronary stenosis, ARDs patients revealed a reduced MPRI in comparison with the general population, regardless of the presence of myocardial fibrosis. Identification of CMD in asymptomatic patients could be crucial to precociously start targeted medical therapy, avoiding major adverse cardiac events in this clinical setting. This review aims to summarize the current evidence regarding CMD in ARDs patients, focusing on the role of stress CMR and the promising myocardial perfusion analysis
Early detection of ventricular dysfunction in juvenile systemic sclerosis by speckle tracking echocardiography
Full text linkObjective: Cardiac involvement is the most important cause of mortality in juvenile systemic sclerosis (JSSc). Recent reports in adult patients underline that traditional techniques of imaging are inadequate to assess the subclinical cardiac involvement, while speckle tracking echocardiography (STE) is able to identify ventricular dysfunctions in the early stages. The aim of our study was to assess the role of STE in JSSc. Methods: Demographic, clinical and laboratory data were collected from patients with JSSc. Cardiac investigations performed at baseline (T0) and 18 (T18) and 36 months (T36) follow-up included electrocardiography, conventional echocardiography with measurement of the ejection fraction (EF) and STE with assessment of left and right ventricular global longitudinal strain (LV-GLS and RV-GLS). Cardiac parameters have been compared with demographic characteristics and disease severity, assessed by the Juvenile Systemic Sclerosis Severity Score (J4S). Results: A total of 18 patients, 12 (67%) females, entered the study. At T0, electrocardiography was abnormal in three patients, EF was reduced in one, LV-GLS was abnormal in three (16.7%) and RV-GLS was abnormal in five (27.8%). At T18, EF remained stable while at T36 the result decreased in seven of nine patients. At the same time, LV-GLS also worsened (from -21.6% to -18.2%, P = 0.01). LV-GLS and RV-GLS at baseline showed a significant correlation with J4S (P = 0.012 and P = 0.02, respectively). Conclusion: STE is more sensitive than standard echocardiography to identify cardiac involvement in JSSc. Over time, we observed a gradual worsening of LV-GLS, a sign of left ventricular dysfunction, that anticipated by several months the decrease of EF
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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