Mild hyperbaric oxygen exposure protects heart during ischemia/reperfusion and affects vascular relaxation.

Mild hyperbaric oxygen therapy (mHBOT) is an adjuvant therapy used in conditions where tissue oxygenation is reduced and is implemented using pressures less than 1.5 ATA and 100% O2 (instead of the classical HBOT at 1.9-3 ATA) which results in cheaper, easier to implement, and equally effective. mHBOT is offered for wellness and beauty and as an anti-aging strategy, in spite of the absence of studies on the cardiovascular system. Consequently, we investigated the impact of mHBOT on the cardiovascular system. Mechanical and energetic parameters of isolated heart submitted to ischemia/reperfusion injury and arterial contractile response from mHBOT-exposed rats were evaluated. In the heart, mHBOT increased pre-ischemic velocity of contraction and ischemic end-diastolic pressure and developed pressure and contractile economy during reperfusion. mHBOT decreased infarct size and increased the plasma nitrite levels. In the artery, mHBOT increased acetylcholine sensitivity. mHBOT protects the heart during ischemia/reperfusion and affects vascular relaxation.

Impact of Obesity on Cardiac Autonomic System Functioning in Military Police Officers.

INTRODUCTION: Cardiac autonomic system functioning may be altered by obesity leading to cardiovascular diseases and associated complications. Military police officers are exposed to traditional and occupational risk factors for the development of CVD, however data on the cardiovascular health in this population is still scarce. AIM: In this cross-sectional study, we investigated the impact of obesity on cardiac autonomic modulation and the hemodynamic profile in male active-duty military police officers. METHODS: The body composition of the volunteers was assessed by octapolar electrical bioimpedance. Participants were classified as non-obese or obese in accordance with their body fat, with further subgroups as physically active obese or insufficiently active obese using International Physical Activity Questionnaire (IPAQ). Cardiac autonomic modulation was assessed by heart rate variability and the automatic oscillometric method allowed us to assess hemodynamic features. RESULTS: 102 military police officers from the state of São Paulo participated in the study. Cardiac autonomic modulation revealed significant impairment in time and frequency domains and non-linear methods in the obese group compared to the non-obese (p < 0.05). A higher physical activity level did not alter these results in the obese group. However, no significant differences in the hemodynamic profile were observed between groups (p > 0.05). CONCLUSION: These findings suggest a negative association between obesity and cardiac autonomic modulation in military police officers, unaffected by increased physical activity.

Unsophisticated assessment of the cardiopulmonary function in patients with pectus excavatum using the six minute walk test.

BACKGROUND: We explored whether the maximum predicted walking distance, assessed with six-minute walk test (6MWT) and reflecting submaximal functional exercise capacity, is decreased among patients with pectus excavatum (PEX). METHODS: This study comprised a retrospective analysis of patients with PEX who underwent a 6MWT for the assessment of functional capacity. The maximum distance walked was recorded and compared to reference values established for different populations, including a young and healthy South American population. RESULTS: We included 43 patients with PEX who underwent 6MWT. The mean age was 17.8 ± 6.7 years. The mean maximum distance walked was significantly lower than the predicted distance (600.8 ± 67.6 metres vs. 729.8 ± 67.5 metres, p < 0.0001). Using the Enright reference equation including an older reference population, the mean negative difference was higher (PEX patients walked 190.4 ± 78.4 metres less than predicted, p < 0.0001). We also applied the Li et al. reference equation accounting for sex among other variables, detecting a decreased walked distance compared to the gender-adjusted predicted distance (PEX patients walked a mean 222.4 ± 87.4 metres less than predicted, p < 0.0001). Using the Ulrich et al. equation, PEX patients walked a mean 114.2 ± 85.1 metres less than predicted (p < 0.0001). Although of uncertain clinical relevance, there was a significant decrease in the mean oxygen saturation after exercise (baseline 97.4 ± 1.2%, vs. final 96.4 ± 2.1%, p = 0.006). CONCLUSIONS: In this study, we identified a significant reduction in the maximum walked distance among patients with PEX compared to the predicted distance, thus potentially emerging as an unsophisticated means to evaluate and quantify functional exercise capacity.

Mecanismos de adaptação do coração em atletas de elite do sexo feminino: comparação com indivíduos sadios e tempo de treinamento / Heart adaptation mechanisms in elite female athletes: comparison with healthy individuals and time of training

Fundamento: O exercício intenso e continuado em atletas provoca fenótipos de remodelamento adaptativo, cujos parâmetros podem ser avaliados pela ecocardiografia convencional, e de deformação miocárdica. Assim, foi comparado o remodelamento miocárdico em atletas do sexo feminino (grupo atletas) com mulheres sedentárias da mesma faixa etária (grupo-controle) e entre atletas com maior e menor tempo de treinamento. Métodos: Foram selecionadas 57 futebolistas femininas (grupo atletas) e 25 mulheres sadias sedentárias (grupocontrole). As atletas foram divididas em dois grupos: grupo principal, com 32 atletas, e grupo sub-17, com 25 atletas. Foram determinadas, através de ecocardiografia, as dimensões, a função sistólica e diastólica das câmaras cardíacas e a deformação miocárdica (strain longitudinal, circunferencial, radial e mecânica rotacional), utilizando a estatística Z com significância de p < 0,05. Resultados: A idade dos grupos atletas, controle, principal e sub-17 foi de 22,1±6,3; 21,2±5,0; 26,5±5,1; e 16,5±0,6, respectivamente. O peso, o índice de massa corporal e a frequência cardíaca foram menores no grupo atletas. A espessura das paredes, o índice de massa do ventrículo esquerdo (VE), o volume do átrio esquerdo (AE), a fração de ejeção e as dimensões do ventrículo direito (VD) foram maiores no grupo atletas, mas dentro de valores normais. A deformação miocárdica mostrou diminuição do strain radial, da rotação basal, da rotação apical e do twist, sugerindo mecanismo de reserva contrátil. Esses parâmetros foram menores no grupo principal, que também apresentava maior espessura das paredes, maior volume do AE e maior tamanho do VD, sugerindo que o aumento da reserva contrátil se relaciona com maior tempo de treinamento. Conclusões: As atletas do sexo feminino com treinamento intenso de longa duração apresentam remodelamento adaptativo das câmaras cardíacas e aumento da reserva contrátil observada em repouso, com esses parâmetros mais acentuados nas atletas com maior tempo de treinamento.(AU)

Background: Intense continuous exercise provokes adaptive remodeling phenotypes in athletes, the parameters of which can be evaluated through conventional echocardiography and myocardial deformation. We compared myocardial remodeling in female athletes (athlete group) with sedentary women of the same age range (control group) and between older and younger athletes. Methods: A total of 57 female soccer players and 25 healthy sedentary women were selected. The athlete group was subdivided into a main group and those under 17 years of age (< 17 group). The dimensions and systolic and diastolic function of the cardiac chambers and myocardial deformation (longitudinal and circumferential, as well as radial strain and rotational mechanics) was determined through echocardiography, using the Z statistic with a significance level of p< 0.05. Results: The mean age of the athlete, control, main, and < 17 groups was 22.1 (SD, 6.3); 21.2 (SD, 5.0); 26.5 (SD, 5.1); 16.5 (SD, 0.6) years, respectively. Weight, body mass index and heart rate were lower in the athlete group. Wall thickness, left ventricular mass index, left atrial (LA) volume, ejection fraction, and right ventricular dimensions were higher in athlete group, but remained within normal ranges. Regarding myocardial deformation, there was decreased radial strain, basal rotation, apical rotation, and twisting in the athlete group, suggesting a contractile reserve mechanism. These parameters were lesser in the main athlete group, who also had greater wall thickness, greater volume in the left atrium (LA) and larger size in the right ventricle (RV), suggesting that increased contractile reserve is related to longer time spent in the sport. Conclusions: In female athletes who had undergone intense long-term training, we observed adaptive remodeling of the cardiac chambers and increased contractile reserve (at rest), and these changes were more pronounced in those with longer involvement in the sport.(AU)

Compound Danshen Dripping Pills pretreatment protects the heart from ischemia/reperfusion injury by enhancing autophagic flux

Abstract Compound Danshen Dripping Pills (CDDPs) have been used in clinical treatment to protect the heart from ischemia/reperfusion (IR) injury for many years. However, the underlying mechanism implicated in the protective effects remains to be explored. Here, we determined the effects of CDDPs in Sprague-Dawley rats with the IR model. Cardiac function in vivo was assessed by echocardiography. Transmission electron microscopy, histological and immunohistochemical techniques, Western blotting and recombinant adeno-associated virus 9 transfection were used to illustrate the effects of CDDPs on IR and autophagy. Our results showed that pretreatment with CDDPs decreased the level of serum myocardial enzymes and infarct size in rats after IR. Apoptosis evaluation showed that CDDPs significantly ameliorated the cardiac apoptosis level after IR. Meanwhile, CDDPs pretreatment increased myocardial autophagic flux, with upregulation of LC3B, downregulation of p62, and increased autophagosomes and autolysosomes. Moreover, the autophagic flux inhibitor chloroquine could increase IR injury, while CDDPs could partially reverse the effects. Furthermore, our results showed that the activation of AMPK/mTOR was involved in the cardioprotective effect exerted by CDDPs. Herein, we suggest that CDDPs partially protect the heart from IR injury by enhancing autophagic flux through the activation of AMPK/mTOR.

Pre-treatment of the beta3-adrenergic receptor agonist BRL37344 reduces in vivo myocardial ischemia/reperfusion injury by improving AMPK and SIRT1 activity and by suppressing mTOR and p70S6K signaling pathways

Abstract This study aimed to investigate the role and signaling pathways of β3-AR in myocardial ischemia/reperfusion (I/R) injury, which is one of the leading causes of death worldwide. 47 male rats were randomly divided into two main groups to evaluate infarct size and molecular parameters. Rats in both groups were randomly divided into 4 groups. Control (sham), I/R (30 min ischemia/120 min reperfusion), BRL37344 (BRL) (A) (5 µg/kg single-dose pre-treatment (preT) before I/R) and BRL (B) (5 µg/kg/day preT for 10 days before I/R). Infarct size was determined with triphenyltetrazolium chloride staining and analyzed with ImageJ program. The levels of AMPK, SIRT1, mTOR, and p70SK6 responsible for cellular energy and autophagy were evaluated by western blot. Infarct size increased in the I/R group (44.84 ± 1.47%) and reduced in the single-dose and 10-day BRL-treated groups (32.22 ± 1.57%, 29.65 ± 0.55%; respectively). AMPK and SIRT1 levels were decreased by I/R but improved in the treatment groups. While mTOR and p70S6K levels increased in the I/R group, they decreased with BRL preT. BRL preT protects the heart against I/R injury. These beneficial effects are mediated in part by activation of AMPK and SIRT1, inhibition of mTOR and p70S6K, and consequently protected autophagy.

Acute high-intensity interval exercise versus moderate-intensity continuous exercise in heated water-based on hemodynamic, cardiac autonomic, and vascular responses in older individuals with hypertension.

OBJECTIVES: This crossover study design aimed to assess hemodynamic, cardiac autonomic, and vascular responses to high-intensity interval (HIIE) vs moderate-intensity continuous exercise (MICE) in older individuals with hypertension. METHODS: Twenty (67 ± 7 y) older individuals with hypertension were randomly assigned to perform HIIE, MICE, or control (CON) sessions in the heated swimming pool (30-32°C). Blood pressure (BP), arterial stiffness, endothelial reactivity, and heart rate variability (HRV) were measured pre, post, and 45 min (recovery) after each intervention followed by 24-h ambulatory BP and HRV. RESULTS: One single aerobic exercise session was not effective to provoke post-exercise hypotension and vascular improvements. HIIE was superior to MICE and CON to increasing parasympathetic modulation at post and recovery. Exercise sessions showed to disturb the autonomic system at nighttime compared to CON. CONCLUSIONS: These results may have important implications in water-based therapy and the elderly with hypertension.

TRPV1 Contributes to Modulate the Nitric Oxide Pathway and Oxidative Stress in the Isolated and Perfused Rat Heart during Ischemia and Reperfusion.

The transient vanilloid receptor potential type 1 (TRPV1) regulates neuronal and vascular functions mediated by nitric oxide (NO) and by the calcitonin gene-related peptide (CGRP). Here, we study the participation of TRPV1 in the regulation of myocardial injury caused by ischemia-reperfusion and in the control of NO, tetrahydrobiopterin (BH4), the cGMP pathway, CGRP, total antioxidant capacity (TAC), malondialdehyde (MDA) and phosphodiesterase-3 (PDE-3). Isolated hearts of Wistar rats perfused according to the Langendorff technique were used to study the effects of an agonist of TRPV1, capsaicin (CS), an antagonist, capsazepine (CZ), and their combination CZ+CS. The hearts were subjected to three conditions: (1) control, (2) ischemia and (3) ischemia-reperfusion. We determined cardiac mechanical activity and the levels of NO, cGMP, BH4, CGRP, TAC, MDA and PDE-3 in ventricular tissue after administration of CS, CZ and CZ+CS. Western blots were used to study the expressions of eNOS, iNOS and phosphorylated NOS (pNOS). Structural changes were determined by histological evaluation. CS prevented damage caused by ischemia-reperfusion by improving cardiac mechanical activity and elevating the levels of NO, cGMP, BH4, TAC and CGRP. TRPV1 and iNOS expression were increased under ischemic conditions, while eNOS and pNOS were not modified. We conclude that the activation of TRPV1 constitutes a therapeutic possibility to counteract the damage caused by ischemia and reperfusion by regulating the NO pathway through CGRP.

Role of ACE and ACE-2 in abrogated cardioprotective effect of ischemic preconditioning in ovariectomized rat heart

Abstract Ischemic heart disease is the leading cause of death in postmenopausal women. The activity of heart ACE increases whereas the activity of ACE-2 decreases after menopause. The present study was designed to investigate the role of ACE and ACE-2 in the abrogated cardioprotective effect of IPC in OVX rat heart. The heart was isolated from OVX rat and mounted on Langendorff's apparatus for giving intermittent cycles of IPC. The infarct size was estimated using TTC stain, and coronary effluent was analyzed for LDH, CK-MB, and nitrite release. IPC induced cardioprotection was significantly attenuated in the ovariectomized rat heart as compared to the normal rat heart. However, this attenuated cardioprotection was significantly restored by perfusion of DIZE, an ACE-2 activator, and captopril, an ACE inhibitor, alone or in combination noted in terms of decrease in myocardial infarct size, the release of LDH and CK-MB, and also increase in the release of NO as compared to untreated OVX rat heart. Thus, it is suggested that DIZE and captopril, alone or in combination restore the attenuated cardioprotective effect of IPC in OVX rat heart which is due to an increase in ACE-2 activity and decrease in ACE activity after treatment.

Impairment of Multiple Mitochondrial Energy Metabolism Pathways in the Heart of Chagas Disease Cardiomyopathy Patients.

Chagas disease cardiomyopathy (CCC) is an inflammatory dilated cardiomyopathy occurring in 30% of the 6 million infected with the protozoan Trypanosoma cruzi in Latin America. Survival is significantly lower in CCC than ischemic (IC) and idiopathic dilated cardiomyopathy (DCM). Previous studies disclosed a selective decrease in mitochondrial ATP synthase alpha expression and creatine kinase activity in CCC myocardium as compared to IDC and IC, as well as decreased in vivo myocardial ATP production. Aiming to identify additional constraints in energy metabolism specific to CCC, we performed a proteomic study in myocardial tissue samples from CCC, IC and DCM obtained at transplantation, in comparison with control myocardial tissue samples from organ donors. Left ventricle free wall myocardial samples were subject to two-dimensional electrophoresis with fluorescent labeling (2D-DIGE) and protein identification by mass spectrometry. We found altered expression of proteins related to mitochondrial energy metabolism, cardiac remodeling, and oxidative stress in the 3 patient groups. Pathways analysis of proteins differentially expressed in CCC disclosed mitochondrial dysfunction, fatty acid metabolism and transmembrane potential of mitochondria. CCC patients' myocardium displayed reduced expression of 22 mitochondrial proteins belonging to energy metabolism pathways, as compared to 17 in DCM and 3 in IC. Significantly, 6 beta-oxidation enzymes were reduced in CCC, while only 2 of them were down-regulated in DCM and 1 in IC. We also observed that the cytokine IFN-gamma, previously described with increased levels in CCC, reduces mitochondrial membrane potential in cardiomyocytes. Results suggest a major reduction of mitochondrial energy metabolism and mitochondrial dysfunction in CCC myocardium which may be in part linked to IFN-gamma. This may partially explain the worse prognosis of CCC as compared to DCM or IC.

High Fasting Glycemia Predicts Impairment of Cardiac Autonomic Control in Adults With Type 2 Diabetes: A Case-Control Study.

Introduction: Type 2 diabetes (T2D) is characterized by a metabolic disorder that elevates blood glucose concentration. Chronic hyperglycemia has been associated with several complications in patients with T2D, one of which is cardiac autonomic dysfunction that can be assessed from heart rate variability (HRV) and heart rate recovery (HRR) response, both associated with many aspects of health and fitness, including severe cardiovascular outcomes. Objective: To evaluate the effects of T2D on cardiac autonomic modulation by means of HRV and HRR measurements. Materials and Methods: This study has an observational with case-control characteristic and involved ninety-three middle-aged adults stratified into two groups (control group - CG, n = 34; diabetes group - DG, n = 59). After signing the free and informed consent form, the patients were submitted to the evaluation protocols, performed biochemical tests to confirm the diagnosis of T2D, collection of R-R intervals for HRV analysis and cardiopulmonary effort test to quantify HRR. Results: At rest, the DG showed a reduction in global HRV (SDNN= 19.31 ± 11.72 vs CG 43.09 ± 12.74, p < 0.0001), lower parasympathetic modulation (RMSSD= 20.49 ± 14.68 vs 52.41 ± 19.50, PNN50 = 4.76 ± 10.53 vs 31.24 ± 19.24, 2VD%= 19.97 ± 10.30 vs 28.81 ± 9.77, p < 0.0001 for both indices) and higher HRrest when compared to CG. After interruption of physical exercise, a slowed heart rate response was observed in the DG when compared to the CG. Finally, a simple linear regression showed that fasting glycemia was able to predict cardiac autonomic involvement in volunteers with T2D. Conclusion: Patients with T2D presented lower parasympathetic modulation at rest and slowed HRR after physical exercise, which may be associated with higher cardiovascular risks. The findings show the glycemic profile as an important predictor of impaired cardiac autonomic modulation.

Impacto cardiovascular, conducta diagnóstica y terapéutica del feocromocitoma como causa de hipertensión arterial / Cardiovascular impact, diagnostic and therapeutic management of pheochromocytoma as a cause of arterial hypertension

INTRODUCCIÓN. Los feocromocitomas son tumores que provienen de las células neuroendócrinas de la médula adrenal y producen alta secreción de catecolaminas. Generan complicaciones cardiovasculares graves que suelen asociarse con crisis hipertensivas. Es importante valorar el impacto cardiovascular de esta entidad. OBJETIVO. Realizar una revisión exhaustiva de las diversas manifestaciones de los feocromocitomas como causa de hipertensión arterial, su impacto cardiovascular, conducta diagnóstica y terapéutica. MATERIALES Y MÉTODOS. Revisión bibliográfica y análisis de 141 artículos científicos que incluyeron temas sobre el impacto cardiovascular, conducta diagnóstica y terapéutica del feocromocitoma como causa de hipertensión arterial. Se usó bases de datos: Medline, Embase, Scopus, Pubmed, Google Académico. Criterios de búsqueda en DECS, MeSH: "pheochromocytoma OR hypertension arterial AND cardiomyopathy", en inglés- español. Fueron seleccionados: 13 publicaciones de texto completo, 10 artículos retrospectivos, 2 guías de práctica clínica y 1 revisión. Se excluyeron 128 artículos científicos. RESULTADOS. Se realizó una revisión de las manifestaciones clínicas de los feocromocitomas como causa de hipertensión arterial y el impacto cardiovascular se relacionó con la producción de catecolaminas. Para el diagnóstico, la sensibilidad de la resonancia magnética es del 93-100%; la especificidad de resonancia magnética o tomografía computarizada en combinación con gammagrafía con metayodobencilguanidina con 123I es cercana al 100%. La resección del feocromocitoma tiene potencial curativo. CONCLUSIÓN. Los feocromocitomas presentan variabilidad clínica, se asocian a complicaciones cardiovasculares y cerebrovasculares graves por producción de catecolaminas. El diagnóstico oportuno y eficaz debe realizarse mediante resonancia magnética y gammagrafía en caso de alta sospecha clínica. El tratamiento quirúrgico es de elección.

INTRODUCTION. Pheochromocytomas are tumors arising from the neuroendocrine cells of the adrenal medulla and produce high secretion of catecholamines. They generate severe cardiovascular complications that are often associated with hypertensive crises. It is important to assess the cardiovascular impact of this entity. OBJECTIVE. To perform an exhaustive review of the various manifestations of pheochromocytomas as a cause of arterial hypertension, their cardiovascular impact, diagnostic and therapeutic conduct. MATERIALS AND METHODS. Bibliographic review and analysis of 141 scientific articles that included topics on the cardiovascular impact, diagnostic and therapeutic behavior of pheochromocytoma as a cause of arterial hypertension. The following databases were used: Medline, Embase, Scopus, Pubmed, Google Scholar. Search criteria in DECS, MeSH: "pheochromocytoma OR hypertension arterial AND cardiomyopathy", in English-Spanish. The following were selected: 13 full-text publications, 10 retrospective articles, 2 clinical practice guidelines, and 1 review. A total of 128 scientific articles were excluded. RESULTS. A review of the clinical manifestations of pheochromocytoma as a cause of arterial hypertension was performed and the cardiovascular impact was related to catecholamine production. For diagnosis, the sensitivity of MRI is 93-100%; the specificity of MRI or computed tomography in combination with 123I-methiodobenzylguanidine scintigraphy is close to 100%. Resection of pheochromocytoma has curative potential. CONCLUSION. Pheochromocytomas present clinical variability, are associated with severe cardiovascular and cerebrovascular complications due to catecholamine production. Timely and effective diagnosis should be made by MRI and scintigraphy in case of high clinical suspicion. Surgical treatment is the treatment of choice.

Extracellular Vesicles and Their Relationship with the Heart-Kidney Axis, Uremia and Peritoneal Dialysis.

Cardiorenal syndrome (CRS) is described as primary dysfunction in the heart culminating in renal injury or vice versa. CRS can be classified into five groups, and uremic toxin (UT) accumulation is observed in all types of CRS. Protein-bound uremic toxin (PBUT) accumulation is responsible for permanent damage to the renal tissue, and mainly occurs in CRS types 3 and 4, thus compromising renal function directly leading to a reduction in the glomerular filtration rate (GFR) and/or subsequent proteinuria. With this decrease in GFR, patients may need renal replacement therapy (RRT), such as peritoneal dialysis (PD). PD is a high-quality and home-based dialysis therapy for patients with end-stage renal disease (ESRD) and is based on the semi-permeable characteristics of the peritoneum. These patients are exposed to factors which may cause several modifications on the peritoneal membrane. The presence of UT may harm the peritoneum membrane, which in turn can lead to the formation of extracellular vesicles (EVs). EVs are released by almost all cell types and contain lipids, nucleic acids, metabolites, membrane proteins, and cytosolic components from their cell origin. Our research group previously demonstrated that the EVs can be related to endothelial dysfunction and are formed when UTs are in contact with the endothelial monolayer. In this scenario, this review explores the mechanisms of EV formation in CRS, uremia, the peritoneum, and as potential biomarkers in peritoneal dialysis.

Accuracy and reliability of focused echocardiography in patients with Chagas disease from endemic areas: SaMi-Trop cohort study.

BACKGROUND: Chagas disease remains a major cause of cardiovascular death in endemic areas. Focused echocardiography (FoCUS) is a point-of-care means of assessing cardiac function which can be useful for the diagnosis of cardiac involvement. OBJECTIVE: This study aims evaluating the characteristics of validity and reliability of FoCUS applied on Chagas disease patients. METHODS: Patients with Chagas disease coming from an endemic area were selected from a large cohort (SaMi-Trop). A simplified echocardiogram with only three images was extracted from the conventional echocardiogram performed in this cohort. The images were evaluated by an observer who was blinded to the clinical and echocardiographic data, to determine the accuracy and reliability of FoCUS for cardiac assessment. The analysis constituted of 5 prespecified variables, dichotomized in absence or presence: left ventricular (LV) size and systolic function, right ventricular (RV) size and systolic function, and LV aneurysm. RESULTS: We included 725 patients with a mean age of 63.4 ± 12.3 years, 483 (67%) female. Abnormal electrocardiogram was observed in 81.5% of the patients. Left and right ventricular dysfunctions were found in 103 (14%) and 49 (7%) of the patients, respectively. Sensitivity, specificity, positive predictive value and negative predictive value were 84%, 94%, 70% and 97% for LV enlargement and 81%, 93%, 68% and 97% for LV systolic dysfunction, respectively, and 46%, 99%, 60% and 98% for RV dilatation, and 37%, 100%, 100% and 96% for RV dysfunction, respectively. Inter and intraobserver agreement were 61% and 87% for LV enlargement and 63% and 92% for LV dysfunction, respectively, and 50% and 49% for RV size and 46% and 79% for RV dysfunction, respectively. LV apical aneurysm was found in 45 patients (6.2%) with the lowest sensitivity of FoCUS study (11%; 95% CI 2-28%). CONCLUSIONS: FoCUS showed satisfactory values of validity and reliability for assessment of cardiac chambers in patients with Chagas disease, except for apical aneurysm. This tool can identify heart disease with potential impact on patient management in the limited-resource setting.

Effects of chronic cholinergic stimulation associated with aerobic physical training on cardiac morphofunctional and autonomic parameters in spontaneously hypertensive rats.

We investigated hemodynamic, cardiac morphofunctional, and cardiovascular autonomic adaptations in spontaneously hypertensive rats (SHRs) after aerobic physical training associated with chronic cholinergic stimulation. Fifty-four SHRs were divided into two groups: trained and untrained. Each group was further subdivided into three smaller groups: vehicle, treated with pyridostigmine bromide at 5 mg/kg/day, and treated with pyridostigmine bromide at 15 mg/kg/day. The following protocols were assessed: echocardiography, autonomic double pharmacological blockade, heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS). Physical training and pyridostigmine bromide reduced BP and HR and increased vagal participation in cardiac autonomic tonic balance. The associated responses were then potentialized. Treatment with pyridostigmine bromide increased HRV oscillation of both low frequency (LF: 0.2-0.75 Hz) and high frequency (HF: 0.75-3 Hz). However, the association with physical training attenuated HF oscillations. Additionally, treatment with pyridostigmine bromide also increased LF oscillations of BPV. Both treatment groups promoted morphofunctional adaptations, and associated increased ejection volume, ejection fraction, cardiac output, and cardiac index. In conclusion, the association of pyridostigmine bromide and physical training promoted greater benefits in hemodynamic parameters and increased vagal influence on cardiac autonomic tonic balance. Nonetheless, treatment with pyridostigmine bromide alone seems to negatively affect BPV and the association of treatment negatively influences HRV.

Heat Shock Proteins: Connectors between Heart and Kidney.

Over the development of eukaryotic cells, intrinsic mechanisms have been developed in order to provide the ability to defend against aggressive agents. In this sense, a group of proteins plays a crucial role in controlling the production of several proteins, guaranteeing cell survival. The heat shock proteins (HSPs), are a family of proteins that have been linked to different cellular functions, being activated under conditions of cellular stress, not only imposed by thermal variation but also toxins, radiation, infectious agents, hypoxia, etc. Regarding pathological situations as seen in cardiorenal syndrome (CRS), HSPs have been shown to be important mediators involved in the control of gene transcription and intracellular signaling, in addition to be an important connector with the immune system. CRS is classified as acute or chronic and according to the first organ to suffer the injury, which can be the heart (CRS type 1 and type 2), kidneys (CRS type 3 and 4) or both (CRS type 5). In all types of CRS, the immune system, redox balance, mitochondrial dysfunction, and tissue remodeling have been the subject of numerous studies in the literature in order to elucidate mechanisms and propose new therapeutic strategies. In this sense, HSPs have been targeted by researchers as important connectors between kidney and heart. Thus, the present review has a focus to present the state of the art regarding the role of HSPs in the pathophysiology of cardiac and renal alterations, as well their role in the kidney-heart axis.

The impact of fluid status and decremental PEEP strategy on cardiac function and lung and kidney damage in mild-moderate experimental acute respiratory distress syndrome.

BACKGROUND: We evaluated the effects of abrupt versus gradual PEEP decrease, combined with standard versus high-volume fluid administration, on cardiac function, as well as lung and kidney damage in an established model of mild-moderate acute respiratory distress syndrome (ARDS). METHODS: Wistar rats received endotoxin intratracheally. After 24 h, they were treated with Ringer's lactate at standard (10 mL/kg/h) or high (30 mL/kg/h) dose. For 30 min, all animals were mechanically ventilated with tidal volume = 6 mL/kg and PEEP = 9 cmH2O (to keep alveoli open), then randomized to undergo abrupt or gradual (0.2 cmH2O/min for 30 min) PEEP decrease from 9 to 3 cmH2O. Animals were then further ventilated for 10 min at PEEP = 3 cmH2O, euthanized, and their lungs and kidneys removed for molecular biology analysis. RESULTS: At the end of the experiment, left and right ventricular end-diastolic areas were greater in animals treated with high compared to standard fluid administration, regardless of PEEP decrease rate. However, pulmonary arterial pressure, indicated by the pulmonary acceleration time (PAT)/pulmonary ejection time (PET) ratio, was higher in abrupt compared to gradual PEEP decrease, independent of fluid status. Animals treated with high fluids and abrupt PEEP decrease exhibited greater diffuse alveolar damage and higher expression of interleukin-6 (a pro-inflammatory marker) and vascular endothelial growth factor (a marker of endothelial cell damage) compared to the other groups. The combination of standard fluid administration and gradual PEEP decrease increased zonula occludens-1 expression, suggesting epithelial cell preservation. Expression of club cell-16 protein, an alveolar epithelial cell damage marker, was higher in abrupt compared to gradual PEEP decrease groups, regardless of fluid status. Acute kidney injury score and gene expression of kidney injury molecule-1 were higher in the high versus standard fluid administration groups, regardless of PEEP decrease rate. CONCLUSION: In the ARDS model used herein, decreasing PEEP abruptly increased pulmonary arterial hypertension, independent of fluid status. The combination of abrupt PEEP decrease and high fluid administration led to greater lung and kidney damage. This information adds to the growing body of evidence that supports gradual transitioning of ventilatory patterns and warrants directing additional investigative effort into vascular and deflation issues that impact lung protection.

Eugenol interacts with cardiac sodium channel and reduces heart excitability and arrhythmias.

AIMS: Eugenol is a natural compound found in the essential oils of many aromatic plants. The compound is used as a local anesthetic because of its inhibitory effect on the voltage-gated Na+ channels (Nav), which are expressed in the nociceptive neurons. Eugenol has shown wide range of activities in the cardiovascular system; most of these activities are attributed to the modulation of voltage-sensitive Ca2+ channels. However, its action on Nav1.5, the main subtype of Nav expressed in the mammalian myocardium, is unknown. The interaction of eugenol with Nav1.5 could also contribute to its antiarrhythmic properties in vitro and ex vivo. We investigated the compound's effect on sodium current (INa) and its possible cardiac antiarrhythmic activity. METHODS: The effect of eugenol on cardiac contractility was investigated using isolated atrium from guinea pig (for isometric force measurements). The compound's effect on INa was evaluated using human embryonic cell transiently expressing human Nav1.5 and patch-clamp technique. KEY FINDINGS: Eugenol caused negative inotropic and chronotropic effects in the atria. In the ex vivo arrhythmia model, eugenol decreased atrial pacing disturbance induced by ouabain. Eugenol reduced the INa in a concentration-dependent manner. Furthermore, the compound left-shifted the stationary inactivation curve, delayed recovery from inactivation of the INa, and preferentially blocked the channel in the inactivated state. Importantly, eugenol was able to attenuate the late sodium current. All these aspects are considered to be antiarrhythmic. SIGNIFICANCE: Overall, our findings demonstrate that eugenol has antiarrhythmic activity due, at least in part, to its interaction with Nav1.5.