Search Results (66)

Metabolic syndrome (MetS) drives cardiac remodeling and fibrosis, contributing to diastolic dysfunction and heart failure with preserved ejection fraction, but chamber-specific mechanisms remain poorly defined. New Zealand White rabbits were fed a high-fat/high-sucrose diet for 28 weeks to induce experimental MetS. Systemic phenotype, cardiac structure (echocardiography), myocardial fibrosis (Picrosirius red histology), myosin/collagen gene expression (qRT-PCR), and chamber-specific proteomics were assessed across left/right atria and ventricles. The model reproduced central obesity, glucose intolerance, dyslipidemia, and mild hypertension, with concentric left ventricular hypertrophy and selective ventricular fibrosis, as follows: increased collagen in left ventricle (LV) and right ventricle (RV), unchanged in atria. Ventricular α-myosin heavy-chain gene expression was upregulated, while collagen I and α-smooth muscle actin transcripts showed ventricular-specific downregulation. Proteomics revealed atrial metabolic and cytoskeletal adaptations with minimal extracellular matrix involvement; ventricles displayed early profibrotic cues (galectin-3 in LV), metabolic inefficiency (impaired glycolysis/ATP production in LV; lipid oxidation shift in RV), and diminished provisional matrix support. Conclusions: concentric LV hypertrophy and great vessel enlargement occurred without systolic/diastolic dysfunction; ventricular-selective fibrosis, α-myosin heavy-chain upregulation, type I collagen/α-smooth muscle actin downregulation, and chamber-specific proteomic changes showed atrial adaptation versus ventricular early profibrotic/metabolic inefficiency. Full article

Background: In patients with left ventricular hypertrophy, resting structural parameters alone may not explain exertional symptoms. Hence, we investigate whether combined Cardiopulmonary Exercise Testing- Exercise Stress Echocardiography (CPET-ESE) can provide an integrated functional characterisation of hypertrophic phenotypes. Methods: As a preliminary investigation, this prospective single-centre pilot study enrols 43 patients, categorised into: obstructive hypertrophic cardiomyopathy (n = 19), transthyretin cardiac amyloidosis (n = 15), or preserved-ejection-fraction hypertrophic phenotypes (n = 9). Patients undergo symptom-limited semi-supine CPET-ESE on an electronically braked cycle ergometer with an individualised ramp protocol. Peak effort is defined by symptom limitation and respiratory exchange ratio criteria ($RER\ge 1.05$), while peak VO₂ is defined as the highest 30 s averaged value. Results: Exercise responses differ across phenotypes. Patients with obstructive hypertrophic cardiomyopathy have higher peak VO₂ than the other groups, despite their lower chronotropic reserve. The preserved-ejection-fraction hypertrophic group shows lower peripheral oxygen extraction, whereas transthyretin amyloidosis shows a mixed central and peripheral limitation pattern. Right ventricle–pulmonary artery uncoupling is observed in the latter two groups. Conclusions: The use of CPET-ESE may help describe distinct physiological exercise profiles in hypertrophic phenotypes, but these findings should be considered exploratory. The small, heterogeneous and single-centre cohort precludes definitive mechanistic or predictive conclusions and supports the need for larger validation studies. Full article

Pathological cardiac hypertrophy, a major contributor to heart failure, is characterized by an abnormal increase in the size of atria and ventricles. In the context of ventricular hypertrophy, the right ventricle (RV) exhibits less resistance to hypertrophy than the left one (LV). Insulin-like growth factors (IGF-1 and IGF-2) are critical for cell growth and provide cardioprotective effects. Pregnancy-associated plasma protein-A (PAPP-A) is a protease that cleaves insulin-like growth factor-binding protein-4 (IGFBP-4) and enhances IGF bioavailability. This study investigated PAPP-A-mediated IGFBP-4 proteolysis—one possible mechanism of IGF release regulation in rat models of right ventricular (RVH) and left ventricular (LVH) hypertrophy. RVH was induced with monocrotaline, and LVH via renovascular hypertension (1 Kidney 1 Clip (1K1C) model). Systolic blood pressure was measured using tail-cuff plethysmography. Heart morphometry was used to assess the mass of cardiac chambers. Cardiomyocyte purity was confirmed via troponin I immunocytochemistry. Plasma natriuretic type-B peptide (BNP) and C-terminal IGFBP-4 (CT-IGFBP-4) concentrations were quantified by fluoroimmunoassay. RVH and LVH were successfully modelled, with 1.6-fold and 1.3-fold increases in RV (p < 0.0001) and LV masses (p < 0.05), respectively. Plasma BNP was 2–3 times higher in LVH versus control rats. Hypertrophied cardiomyocytes secreted significantly more BNP than controls, showing 3.3-fold and 4.1-fold increases in LVH and RVH, respectively. PAPP-A-mediated IGFBP-4 proteolysis was 4-fold higher in RVH compared to control, but unaffected in LVH. These findings suggest that PAPP-A-specific elevation of IGFBP-4 proteolysis occurs predominantly in RVH, suggesting a differential IGF bioavailability in both ventricles and highlighting PAPP-A as a potential target to increase RVH resistance to hypertrophy. Full article

Background. Gestational diabetes mellitus (GDM) induces maternal hyperglycemia, which may alter fetal cardiac structure and function, increasing short- and long-term cardiovascular risks. Purpose. To systematically review the evidence on the fetal cardiac structural and functional effects of GDM, to explore the diagnostic role of novel imaging and biochemical biomarkers, and to summarize the long-term cardiovascular complications associated with GDM. Materials and Methods. A systematic search of PubMed, Scopus, and Cochrane Library was conducted according to the PRISMA guidelines. All studies comparing cardiac outcomes in GDM and non-GDM pregnancies were included. Data on myocardial hypertrophy, diastolic and systolic function, imaging modalities, and biomarkers were extracted and qualitatively synthesized. Results. A total of twelve eligible studies were identified. Fetal cardiac hypertrophy and diastolic and early systolic dysfunction are common among GDM pregnancies and can be detected by dual-gate Doppler and speckle-tracking echocardiography. Abnormalities are observed in indices such as the myocardial performance index, E/A, E/e′ ratios, and global longitudinal and circumferential strain in fetuses and may persist in the neonatal period. Alterations may be more pronounced for the right ventricle compared to the left. Septal hypertrophy is associated with elevated umbilical cord pro-brain natriuretic peptide. The risk of early-onset cardiovascular disease in the progeny of diabetic mothers is 29% higher, as evidenced by population-based cohort data. Conclusions. GDM is linked to fetal cardiac remodeling and an increased long-term cardiovascular risk. Early detection and customized interventions to reduce adverse outcomes may be achieved by integrating advanced echocardiographic techniques and biomarkers into prenatal surveillance. Full article

A 2-year-old Aberdeen Angus cow was presented with lethargy and decreased appetite at the VA-MD College of Veterinary Medicine Large Animal Teaching Hospital. Initial clinical examination revealed cyanosis, tachycardia, polycythemia, and a significant increase in lactate levels. The heifer experienced spontaneous death while hospitalized, prompting a postmortem examination. Gross evaluation demonstrated that the aorta arose entirely from the right ventricle, while the main pulmonary artery maintained its normal position, consistent with a diagnosis of double-outlet right ventricle. Additional cardiac abnormalities were identified, including an atrial septal defect, ventricular septal defect and marked right ventricular hypertrophy. These defects fall under the category of double-outlet right ventricle malformation. While congenital heart defects are a more recognized cause of cardiac failure and mortality in calves, they should remain a consideration in cases of sudden death, even in adult cattle. Full article

Background: Right heart catheterization (RHC) is the gold-standard for diagnosis of pulmonary hypertension (PH) but is a terminal procedure in neonatal mice. The objective was to validate echocardiographic measures of PH to establish the diagnostic capability against pulmonary vascular histology in neonatal mice. Methods: Adult mice, exposed to hypoxia or normoxia, were assessed by echocardiography and RHC to evaluate right ventricle (RV) morphometry and function. Echocardiographic measures identified in adult mice were then used to evaluate PH characteristics in hypoxia-exposed neonatal mice. Physiological parameters were compared to histopathology in all mice. Results: Hypoxia-challenged adult mice developed PH with RHC, demonstrating confirmed elevated RV systolic pressure (RVSP), RV hypertrophy, and increased cross-sectional area and neomuscularization of pulmonary vessels. Echocardiography-derived RV free wall (RVFW) thickness correlated with RV mass. Tricuspid valve annulus tissue Doppler imaging (TV TDI), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery acceleration measures (PAAT), and TAPSE × PAAT (a measure of RV work) all correlated with RVSP determined by RHC. In neonatal mice exposed to hypoxia, PAAT, TV TDI, TAPSE, and TAPSE × PAAT were decreased and RVFW thickness was increased, correlating with the histologic phenotype of PH. Conclusions: Echocardiographic indices of RV morphology and function provide reliable estimates of invasive RV hemodynamics in hypoxia-induced PH. Full article

The image represents the post-mortem heart of a 28-year-old female patient, diagnosed in childhood with complete common atrioventricular canal defect. At time of diagnosis, the family refused surgery, as did the patient during her adulthood. Despite being advised against pregnancy, she became pregnant. On presentation to hospital, she was cyanotic, with clubbed fingers, and hemodynamically unstable, in sinus rhythm, with Eisenmenger syndrome and respiratory failure partially responsive to oxygen. During pregnancy, owing to systemic vasodilatation, the right-to-left shunt is increased, with more severe cyanosis and low cardiac output. Echocardiography revealed the complete common atrioventricular canal defect, with a single atrioventricular valve with severe regurgitation, right ventricular hypertrophy, pulmonary artery dilatation, severe pulmonary hypertension and a hypoplastic left ventricle. The gestational age at delivery was 38 weeks. She gave birth to a healthy boy, with an Apgar score of 10. The vaginal delivery was chosen by an interdisciplinary team. The cesarean delivery and the anesthesia were considered too risky compared to vaginal delivery. Three days later, the patient died. The autopsy revealed hepatomegaly, a greatly hypertrophied right ventricle with a purplish clot ascending the dilated pulmonary arteries and a hypoplastic left ventricle with a narrowed chamber. A single valve was observed between the atria and ventricles, making all four heart chambers communicate, also insufficiently developed interventricular septum and its congenital absence in the cranial third. These morphological changes indicate the complete common atrioventricular canal defect, with right ventricular dominance, which is a rare and impressive malformation that requires mandatory treatment in early childhood in order for the condition to be solved. Full article

Pulmonary arterial hypertension (PAH) is a rare, progressive, and incurable disease characterized by an elevated pulmonary blood pressure, extensive remodeling of the pulmonary vasculature, increased pulmonary vascular resistance, and culminating in right ventricular failure. Mitochondrial dysfunction has a major role in the pathogenesis of PAH and secondary right ventricular failure, and its targeting may offer therapeutic benefit. In this study, we provide proof-of-concept for the use of the mitochondrially active drug SUL-150 to treat PAH. PAH was induced in rats by monocrotaline, followed by the placement of an aortocaval shunt one week later. The mitoprotective compound SUL-150 (~6 mg·kg⁻¹·day⁻¹) or vehicle was administered intraperitoneally via osmotic minipump for 28 days, implanted at the time of aortocaval shunt placement. Vehicle-treated PAH rats had dyspnea and showed pulmonary artery remodeling with increased responsiveness to phenylephrine, in addition to remodeling of the intrapulmonary arterioles. SUL-150 administration mitigated the dyspnea and the remodeling responses. Vehicle-treated PAH rats developed right ventricular hypertrophy, fibrosis, and failure. SUL-150 administration precluded cardiomyocyte hypertrophy and inhibited ventricular fibrogenesis. Right ventricular failure in vehicle-treated PAH rats induced mitochondrial loss and dysfunction associated with a decrease in mitophagy. SUL-150 was unable to prevent the mitochondrial loss but improved mitochondrial health in the right ventricle, which culminated in the preservation of right ventricular function. We conclude that SUL-150 improves PAH-associated morbidity by the amelioration of pulmonary vascular remodeling and right ventricular failure and may be considered a promising therapeutic candidate to slow disease progression in pulmonary arterial hypertension and secondary right ventricular failure. Full article

Tricuspid regurgitation (TR) represents a significant, often silently progressing, valvular heart disease with historically suboptimal management due to perceived high surgical risks. Transcatheter tricuspid valve interventions (TTVI) offer a promising, less invasive therapeutic avenue. Central to the success of TTVI is Right Ventricular Reverse Remodelling (RVRR), defined as an improvement in RV structure and function, which strongly correlates with enhanced patient survival. The right ventricle (RV) undergoes complex multi-scale biomechanical maladaptations, progressing from adaptive concentric to maladaptive eccentric hypertrophy, coupled with increased stiffness and fibrosis. Molecular drivers of this pathology include early failure of antioxidant defenses, metabolic shifts towards glycolysis, and dysregulation of microRNAs. Accurate RV function assessment necessitates advanced imaging modalities like 3D echocardiography, Cardiac Magnetic Resonance Imaging (CMR), and Computed Tomography (CT), along with strain analysis. Following TTVI, RVRR typically manifests as a biphasic reduction in RV volume overload, improved myocardial strain, and enhanced RV-pulmonary arterial coupling. Emerging molecular biomarkers alongside advanced imaging-derived biomechanical markers like CT-based 3D-TAPSE and RV longitudinal strain, are proving valuable. Artificial intelligence (AI) and machine learning (ML) are transforming prognostication by integrating diverse clinical, laboratory, and multi-modal imaging data, enabling unprecedented precision in risk stratification and optimizing TTVI strategies. Full article

Morphometric cardiac reference values are reported for macropods and koalas (Phascolarctos cinereus). Body weight (BW), heart weight (HW), left ventricle (LV) wall, interventricular septum (S), right ventricle (RV) wall thickness, and LV+S and RV weights were measured at postmortem examination of 48 macropods and 32 koalas that had no evidence of cardiovascular disease. The HW/BW% (0.43–0.96%) and (LV+S)/RV (2.80–4.22) for macropods were comparable to domestic species. In koalas, the HW/BW% (0.25–0.51%) was lower, and the (LV+S)/RV (3.06–5.41) ranged higher than in macropods and domestic species. The LV:RV of koalas (1.0–10.8) was more variable than in macropods (1.17–4.27). Two macropods with cardiac disease were assessed on postmortem examination against the generated reference values. An adult male common wallaroo (Osphranter robustus) was found dead with copious serous peritoneal effusion, chronic passive hepatic congestion with centrilobular fibrosis, and dilation of the RV, while the LV:RV was elevated, supportive of RV thinning. A 21-year-old female zoo-housed Matschie’s tree kangaroo (Dendrolagus matschiei) had a flaccid thin-walled RV, LV cardiomyocyte hypertrophy, interstitial myocardial fibrosis and myofiber degeneration, pulmonary oedema, and serous pericardial effusion. The (LV+S)/RV and LV:RV were elevated and RV:S decreased, supporting left hypertrophic cardiomyopathy. Species-specific reference values presented in this study facilitate objective and improved postmortem cardiac assessment in macropods and koalas. Full article

Acute heart failure (AHF) is a complex clinical syndrome characterized by the rapid or gradual onset of symptoms and/or signs of heart failure (HF), leading to an unplanned hospital admission or an emergency department visit. AHF is the leading cause of hospitalization in patients over 65 years, thus significantly impacting public health care. However, its prognosis remains poor with high rates of mortality and rehospitalization. Many pre-existing cardiac conditions can lead to AHF, but it can also arise de novo due to acute events. Therefore, understanding AHF etiology could improve patient management and outcomes. Cardiomyopathies (CMPs) are a heterogeneous group of heart muscle diseases, including dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), restrictive cardiomyopathy (RCM), non-dilated cardiomyopathy (NDLVC), and arrhythmogenic right ventricular cardiomyopathy (ARVC), that frequently present with HF. Patients with CMPs are under-represented in AHF studies compared to other etiologies, and therefore therapeutic responses and prognoses remain unknown. In DCM, AHF represents the most frequent cause of death despite treatment improvements. Additionally, DCM is the first indication for heart transplant (HT) among young and middle-aged adults. In HCM, the progression to AHF is rare and more frequent in patients with concomitant severe left ventricle (LV) obstruction and hypertrophy or severe LV systolic dysfunction. HF is the natural evolution of patients with RCM and HF is associated with poor outcomes irrespective of RCM etiology. Furthermore, while the occurrence of AHF is rare among patients with ARVC, this condition in NDLVC patients is currently unknown. In this manuscript, we assessed the available evidence on AHF in patients with CMPs. Data on clinical presentation, therapeutic management, and clinical outcomes according to specific CMPs are limited. Future HF studies assessing the clinical presentation, treatment, and prognosis of specific CMPs are warranted. Full article

In Chile, individuals are commonly exposed to high altitude due to the work shift system, involving days of exposure to high altitude followed by days at sea level over the long term, which can result in chronic intermittent hypobaric hypoxia (CIHH). CIHH can cause high-altitude pulmonary hypertension (HAPH), the principal manifestation of which is right ventricular hypertrophy (RVH), in some cases leading to heart failure and eventually death. Studies have shown the contribution of oxidative stress and inflammation to RVH development. Recently, it was determined that the pigment astaxanthin has high antioxidant capacity and strong anti-inflammatory and cardioprotective effects. Therefore, the aim of this study was to determine the effects of astaxanthin on RVH development in rats subjected to CIHH. Methods: Thirty two male Wistar rats were randomly assigned to the following groups (n = 8 per group): the normoxia with vehicle (NX), normoxia with astaxanthin (NX + AS), chronic intermittent hypobaric hypoxia with vehicle (CIHH), and chronic intermittent hypobaric hypoxia with astaxanthin (CIHH + AS) groups. CIHH was simulated by 2 days in a hypobaric chamber followed by 2 days at sea level for 29 days. Results: Exposure to CIHH induced RVH and increased lipid peroxidation (MDA), Nox2 expression, and SOD activity, however, it decreased pro-IL-1β expression. Astaxanthin restored oxidative stress markers (Nox2 and MDA), increased GPx activity, and decreased RVH compared to CIHH. Conclusion: Astaxanthin alleviates RVH and reduces Nox2 and MDA levels while increasing GPx activity in rats subjected to CIHH. These findings provide new insights of astaxanthin as a new nutraceutical against high-altitude effects. Full article

Spontaneously hypertensive rats (SHRs) develop severe hypertension and subsequently left ventricular hypertrophy. Whether they also develop right ventricular hypertrophy is not clear. We analyzed 76 female SHRs (strain SHR/NHsd) and observed severe right ventricular hypertrophy in 7% of these rats (SHR-RVH). Right ventricular hypertrophy did not correlate with the age of the rats and was already seen in one rat at the pre-hypertensive state. The current study investigated the molecular fingerprint of the lung and right ventricle from SHR-RVH and compared this first to SHRs that did develop left but not right ventricular hypertrophy, and second to normotensive rats without hypertrophy. Rats with right ventricular hypertrophy had a decreased expression of the endothelin-B receptor (EDNRB) in the lung, together with an increased protein content of endothelin-1 and an increased expression of ACTA2A. Furthermore, in the right ventricle, a down-regulation of the endothelin-A receptor (EDNRA) was found, consistent with a mild phenotype. The data suggest that in a sub-group of SHR/NHsd rats, low expression of the endothelin clearance receptor (endothelin-B receptor) in the lung triggers an increase in vascular resistance to the right ventricle that then triggers hypertrophy. Our study is the first description of a genetic variant in a defined SHR strain. Full article

Previous experimental findings have led to considerable interest in the beneficial effects on pulmonary hypertension (PH) produced by sildenafil and in the pleiotropic effects of rosuvastatin and their positive role in the process of pulmonary angiogenesis. However, magnesium sulfate, the most abundant intracellular cation, is essential in vascular endothelial functionality due to its anti-inflammatory and vasodilatory effects. Therefore, the present study aims to assess these treatment regimens and how they could potentially provide some additional benefits in PH therapy. Fourteen days after chronic-hypoxia PH was induced, rosuvastatin, sildenafil and magnesium sulfate were administered for an additional fourteen days to male Wistar rats. The Fulton Index, right ventricle (RV) anterior wall thickness, RV internal diameter and pulmonary arterial (PA) acceleration time/ejection time were evaluated, and another four biochemical parameters were calculated: brain natriuretic peptide, vascular endothelial growth factor, nitric oxide metabolites and endothelin 1. The present study demonstrates that sildenafil and rosuvastatin have modest effects in reducing RV hypertrophy and RV systolic pressure. The drug combination of sildenafil + rosuvastatin + magnesium sulfate recorded statistically very highly significant results on all parameters; through their positive synergistic effects on vascular endothelial function, oxidative stress and pathological RV remodeling, they attenuated PH in the chronic hypoxia pulmonary hypertension (CHPH) rat model. Full article

Pulmonary artery hypertension (PAH) is characterised by increased pulmonary vascular resistance (PVR) resulting in elevated pressure in the pulmonary artery supplying the pulmonary circulation. Disease of the right ventricle (RV) often manifests as a result of PAH placing excessive pressure on the right side of the heart. Although a relatively rare disease in humans, the impact of sustained PAH is severe, with poor outcomes even in treated individuals. As PAH develops, the blood flow is restricted through the pulmonary arteries and the right ventricle hypertrophies due to the increased strain of pumping blood through the pulmonary circulation. With time, RV hypertrophy progresses to right heart failure, impacting the supply of blood to the left ventricle and systemic circulation. Although right heart failure can currently be treated, it cannot be cured. There is therefore a need for more research into the physiological changes that cause the heart to fail under pressure overload. This review aims to evaluate the monocrotaline (MCT) rat model of PAH as a means of studying the cellular mechanisms associated with the development of RV hypertrophy and right heart failure. Full article