986 resultados para Hypertrophy, left ventricular


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Background. We assessed end-diastolic right ventricular (RV) dimensions and left ventricular (LV) ejection fraction by use of intraoperative transesophageal echocardiography before and after surgical correction of pectus excavatum in adults. Methods. A prospective study was conducted including 17 patients undergoing surgical correction of pectus excavatum according to the technique of Ravitch-Shamberger between 1999 and 2004. Intraoperative transesophageal echocardiography was performed under general anesthesia before and after surgery to assess end-diastolic RV dimensions and LV ejection fraction. The end-diastolic RV diameter and area were measured in four-chamber and RV inflow-outflow view, and the RV volume was calculated from these data. The LV was assessed by transgastric short-axis view, and its ejection fraction was calculated by use of the Teichholz formula. Results. The end-diastolic RV diameter, area, and volume all significantly increased after surgery (mean values +/- SD, respectively: 2.4 +/- 0.8 cm versus 3.0 +/- 0.9 cm, p < 0.001; 12.5 +/- 5.2 cm(2) versus 18.4 +/- 7.5 cm(2), p < 0.001; and 21.7 +/- 11.7 mL versus 40.8 +/- 23 mL, p < 0.001). The LV ejection fraction also significantly increased after surgery (58.4% +/- 15% versus 66.2% +/- 6%, p < 0.001). Conclusions. Surgical correction of pectus excavatum according to Ravitch-Shamberger technique results in a significant increase in end-diastolic RV dimensions and a significantly increased LV ejection fraction. (Ann Thorac Surg 2010; 89: 240-4) (C) 2010 by The Society of Thoracic Surgeons

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OBJECTIVES: The aim of this study was to evaluate right ventricular (RV) and left ventricular function and pulmonary circulation in chronic mountain sickness (CMS) patients with rest and stress echocardiography compared with healthy high-altitude (HA) dwellers. BACKGROUND: CMS or Monge's disease is defined by excessive erythrocytosis (hemoglobin >21 g/dl in males, 19 g/dl in females) and severe hypoxemia. In some cases, a moderate or severe increase in pulmonary pressure is present, suggesting a similar pathogenesis of pulmonary hypertension. METHODS: In La Paz (Bolivia, 3,600 m sea level), 46 CMS patients and 40 HA dwellers of similar age were evaluated at rest and during semisupine bicycle exercise. Pulmonary artery pressure (PAP), pulmonary vascular resistance, and cardiac function were estimated by Doppler echocardiography. RESULTS: Compared with HA dwellers, CMS patients showed RV dilation at rest (RV mid diameter: 36 ± 5 mm vs. 32 ± 4 mm, CMS vs. HA, p = 0.001) and reduced RV fractional area change both at rest (35 ± 9% vs. 43 ± 9%, p = 0.002) and during exercise (36 ± 9% vs. 43 ± 8%, CMS vs. HA, p = 0.005). The RV systolic longitudinal function (RV-S') decreased in CMS patients, whereas it increased in the control patients (p < 0.0001) at peak stress. The RV end-systolic pressure-area relationship, a load independent surrogate of RV contractility, was similar in CMS patients and HA dwellers with a significant increase in systolic PAP and pulmonary vascular resistance in CMS patients (systolic PAP: 50 ± 12 mm Hg vs. 38 ± 8 mm Hg, CMS vs. HA, p < 0.0001; pulmonary vascular resistance: 2.9 ± 1 mm Hg/min/l vs. 2.2 ± 1 mm Hg/min/l, p = 0.03). Both groups showed comparable systolic and diastolic left ventricular function both at rest and during stress. CONCLUSIONS: Comparable RV contractile reserve in CMS and HA suggests that the lower resting values of RV function in CMS may represent a physiological adaptation to chronic hypoxic conditions rather than impaired RV function. (Chronic Mountain Sickness, Systemic Vascular Function [CMS]; NCT01182792).

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Recent progress in cancer therapy has dramatically modified the course and prognosis of some malignancies. Chemo and radiotherapy, along with newer targeted treatments, are given to control symptoms, postpone relapse, or attempt cure. However, many of these regimens are associated with adverse cardiovascular effects such as impaired left ventricular function, myocardial ischemia, hypertension, and arrhythmia. Awareness of potential cardiotoxicity is important, as it may allow practitioners to recognize early signs of cardiac complications and to adapt therapy in order to limit detrimental effects. Diagnosis of cardiovascular complications may iustify the introduction of cardiologic therapies, and may require the reassessment of risk/benefit ratios related to specific cancer therapy. Screening and follow up strategies are proposed.

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Acute myocardial dysfunction is a typical manifestation of septic shock. Experimentally, the administration of endotoxin [lipopolysacharride (LPS)] to laboratory animals is frequently used to study such dysfunction. However, a majority of studies used load-dependent indexes of cardiac function [including ejection fraction (EF) and maximal systolic pressure increment (dP/dt(max))], which do not directly explore cardiac inotropism. Therefore, we evaluated the direct effects of LPS on myocardial contractility, using left ventricular (LV) pressure-volume catheters in mice. Male BALB/c mice received an intraperitoneal injection of E. coli LPS (1, 5, 10, or 20 mg/kg). After 2, 6, or 20 h, cardiac function was analyzed in anesthetized, mechanically ventilated mice. All doses of LPS induced a significant drop in LV stroke volume and a trend toward reduced cardiac output after 6 h. Concomitantly, there was a significant decrease of LV preload (LV end-diastolic volume), with no apparent change in LV afterload (evaluated by effective arterial elastance and systemic vascular resistance). Load-dependent indexes of LV function were markedly reduced at 6 h, including EF, stroke work, and dP/dt(max). In contrast, there was no reduction of load-independent indexes of LV contractility, including end-systolic elastance (ejection phase measure of contractility) and the ratio dP/dt(max)/end-diastolic volume (isovolumic phase measure of contractility), the latter showing instead a significant increase after 6 h. All changes were transient, returning to baseline values after 20 h. Therefore, the alterations of cardiac function induced by LPS are entirely due to altered loading conditions, but not to reduced contractility, which may instead be slightly increased.

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OBJECTIVES: The purpose of this study was to evaluate the association between inflammation and heart failure (HF) risk in older adults. BACKGROUND: Inflammation is associated with HF risk factors and also directly affects myocardial function. METHODS: The association of baseline serum concentrations of interleukin (IL)-6, tumor necrosis factor-alpha, and C-reactive protein (CRP) with incident HF was assessed with Cox models among 2,610 older persons without prevalent HF enrolled in the Health ABC (Health, Aging, and Body Composition) study (age 73.6 +/- 2.9 years; 48.3% men; 59.6% white). RESULTS: During follow-up (median 9.4 years), HF developed in 311 (11.9%) participants. In models controlling for clinical characteristics, ankle-arm index, and incident coronary heart disease, doubling of IL-6, tumor necrosis factor-alpha, and CRP concentrations was associated with 29% (95% confidence interval: 13% to 47%; p < 0.001), 46% (95% confidence interval: 17% to 84%; p = 0.001), and 9% (95% confidence interval: -1% to 24%; p = 0.087) increase in HF risk, respectively. In models including all 3 markers, IL-6, and tumor necrosis factor-alpha, but not CRP, remained significant. These associations were similar across sex and race and persisted in models accounting for death as a competing event. Post-HF ejection fraction was available in 239 (76.8%) cases; inflammatory markers had stronger association with HF with preserved ejection fraction. Repeat IL-6 and CRP determinations at 1-year follow-up did not provide incremental information. Addition of IL-6 to the clinical Health ABC HF model improved model discrimination (C index from 0.717 to 0.734; p = 0.001) and fit (decreased Bayes information criterion by 17.8; p < 0.001). CONCLUSIONS: Inflammatory markers are associated with HF risk among older adults and may improve HF risk stratification.

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Purpose: The M-band is an important cytoskeletal structure in the centre of the sarcomere, believed to cross-link the thick filament lattice. Its main components are three closely related modular proteins from the myomesin gene family: Myomesin, M-protein and myomesin-3. Each muscle is characterized by its unique M-band protein composition, depending on the contractile parameters of a particular fiber. To investigate the role of the M-band in one of the most relevant and clinically increasing cardiac diseases, we analyzed the expression of myomesin proteins in dilated cardiomyopathy (DCM).Methods: In a previous study we analyzed mouse models suffering from DCM, demonstrating that the embryonic heart specific EH-myomesin splicing isoform was up-regulated directly corresponding to the degree of cardiac dysfunction and ventricular dilation. Based on this study, human ventricular and atrial samples (n=32) were obtained during heart surgery after informed consent and approval by an institutional review board. Patients were aged 30-70 years and suffered from dilated cardiomyopathy (DCM;n=13), Hypertrophic Cardiomyopathy (HCM;n=10) or served as controls (n=9). Patients suffering from DCM or HCM were in endstage heart-failure (NYHA III-IV) and either underwent heart transplantation or Left Ventricular Assist Device (LVAD) implantation. Heart samples from patients who underwent valve surgery or congenital heart surgery served as controls. Heart Samples were analyzed using RT-PCR, Western blot, and immunofluorescence.Results: By investigating the expression pattern of myomesins, we found that DCM is accompanied by specific M-band alterations, which were more pronounced in ventricular samples compared to the atrium. Changes in the amounts of different myomesins during DCM occurred in a cell-specific manner, leading to a higher heterogeneity of the cytoskeleton in cardiomyocytes through the myocardial wall with some cells switching completely to an embryonic phenotype.Conclusions: Here we present that the embryonic heart specific EH-myomesin isoform is up-regulated in human DCM. The alterations of the M-band protein composition might be part of a general adaptation of the sarcomeric cytoskeleton to unfavorable working conditions in the failing heart and may modify the mechanical properties of the cardiomyocytes. We suggest that the upregulation of EH-myomesin might play a pivotal role in DCM and might support classical imagingas a novel sarcomeric marker for this disease.

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Objectives In this study, we have investigated the effects of cannabidiol (CBD) on myocardial dysfunction, inflammation, oxidative/nitrative stress, cell death, and interrelated signaling pathways, using a mouse model of type I diabetic cardiomyopathy and primary human cardiomyocytes exposed to high glucose. Background Cannabidiol, the most abundant nonpsychoactive constituent of Cannabis sativa (marijuana) plant, exerts anti-inflammatory effects in various disease models and alleviates pain and spasticity associated with multiple sclerosis in humans. Methods Left ventricular function was measured by the pressure-volume system. Oxidative stress, cell death, and fibrosis markers were evaluated by molecular biology/biochemical techniques, electron spin resonance spectroscopy, and flow cytometry. Results Diabetic cardiomyopathy was characterized by declined diastolic and systolic myocardial performance associated with increased oxidative-nitrative stress, nuclear factor-kappa B and mitogen-activated protein kinase (c-Jun N-terminal kinase, p-38, p38 alpha) activation, enhanced expression of adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1), tumor necrosis factor-alpha, markers of fibrosis (transforming growth factor-beta, connective tissue growth factor, fibronectin, collagen-1, matrix metalloproteinase-2 and -9), enhanced cell death (caspase 3/7 and poly[adenosine diphosphate-ribose] polymerase activity, chromatin fragmentation, and terminal deoxynucleotidyl transferase dUTP nick end labeling), and diminished Akt phosphorylation. Remarkably, CBD attenuated myocardial dysfunction, cardiac fibrosis, oxidative/nitrative stress, inflammation, cell death, and interrelated signaling pathways. Furthermore, CBD also attenuated the high glucose-induced increased reactive oxygen species generation, nuclear factor-kappa B activation, and cell death in primary human cardiomyocytes. Conclusions Collectively, these results coupled with the excellent safety and tolerability profile of CBD in humans, strongly suggest that it may have great therapeutic potential in the treatment of diabetic complications, and perhaps other cardiovascular disorders, by attenuating oxidative/nitrative stress, inflammation, cell death and fibrosis. (J Am Coll Cardiol 2010;56:2115-25) (C) 2010 by the American College of Cardiology Foundation.

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Transcatheter aortic valve implantation is a feasible therapeutic option for selected patients with severe aortic stenosis and high or prohibitive risk for standard surgery. Lung transplant recipients are often considered high-risk patients for heart surgery because of their specific transplant-associated characteristics and comorbidities. We report a case of successful transfemoral transcatheter aortic valve replacement in a lung transplant recipient with a symptomatic severe aortic stenosis, severe left ventricular dysfunction, and end-stage renal failure 9 years after bilateral lung transplantation.

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OBJECTIVE: Diaphragmatic navigators are frequently used in free-breathing coronary MR angiography, either to gate or prospectively correct slice position or both. For such approaches, a constant relationship between coronary and diaphragmatic displacement throughout the respiratory cycle is assumed. The purpose of this study was to evaluate the relationship between diaphragmatic and coronary artery motion during free breathing. SUBJECTS AND METHODS: A real-time echoplanar MR imaging sequence was used in 12 healthy volunteers to obtain 30 successive images each (one per cardiac cycle) that included the left main coronary artery and the domes of both hemidiaphragms. The coronary artery and diaphragm positions (relative to isocenter) were determined and analyzed for effective diaphragmatic gating windows of 3, 5, and 7 mm (diaphragmatic excursions of 0-3, 0-5, and 0-7 mm from the end-expiratory position, respectively). RESULTS: Although the mean slope correlating the displacement of the right diaphragm and the left main coronary artery was approximately 0.6 for all diaphragmatic gating windows, we also found great variability among individual volunteers. Linear regression slopes varied from 0.17 to 0.93, and r2 values varied from .04 to .87. CONCLUSION: Wide individual variability exists in the relationship between coronary and diaphragmatic respiratory motion during free breathing. Accordingly, coronary MR angiographic approaches that use diaphragmatic navigator position for prospective slice correction may benefit from patient-specific correction factors. Alternatively, coronary MR angiography may benefit from a more direct assessment of the respiratory displacement of the heart and coronary arteries, using left ventricular navigators.

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We report here the case of a 55 year old female that underwent surgery for a well differentiated squamous cell carcinoma of the esophagus (middle third). Four months after surgery, she complains of neck pain, for which she is prescribed non steroidal antiinflammatory drugs (NSAID). A CT-scan and a Barium swallow are then normal. After three weeks of treatment, the patient is admitted on emergency to the Intensive Care Unit for a resuscitation hematemesis and atrial fibrillation with a fast ventricular response. The symptoms are stabilized after the transfusion of a few packed red blood cells. A few hours later, however, a massive hematemesis recurs and the patient dies despite intense resuscitation measures. Autopsy reveals three gastric ulcers, one of which had perforated through the cardiac left ventricular wall

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PURPOSE: The aim of the study was to determine whether glucose uptake in viable myocardium of ischemic cardiomyopathy patients depends on rest myocardial blood flow (MBF) and the residual myocardial flow reserve (MFR). METHODS: Thirty-six patients with ischemic cardiomyopathy (left ventricular ejection fraction 25 ± 10 %) were studied with N-ammonia and F-fluorodeoxyglucose (FDG) positron emission tomography (PET). Twenty age-matched normals served as controls. Regional MBF was determined at rest and during dipyridamole hyperemia and regional FDG extraction was estimated from regional FDG to N-ammonia activity ratios. RESULTS: Rest MBF was reduced in viable (0.42 ± 0.18 ml/min per g) and nonviable regions (0.32 ± 0.09 ml/min per g) relative to remote regions (0.68 ± 0.23 ml/min per g, p < 0.001) and to normals (0.63 ± 0.13 ml/min per g). Dipyridamole raised MBFs in controls, remote, viable, and nonviable regions. MBFs at rest (p < 0.05) and stress (p < 0.05) in viable regions were significantly higher than that in nonviable regions, while MFRs did not differ significantly (p > 0.05). Compared to MFR in remote myocardium, MFRs in viable regions were similar (1.39 ± 0.56 vs 1.70 ± 0.45, p > 0.05) but were significantly lower in nonviable regions (1.23 ± 0.43, p < 0.001). Moreover, the FDG and thus glucose extraction was higher in viable than in remote (1.40 ± 0.14 vs 0.90 ± 0.20, p < 0.001) and in nonviable regions (1.13 ± 0.21, p < 0.001). The extraction of FDG in viable regions was independent of rest MBF but correlated inversely with MFRs (r =-0.424, p < 0.05). No correlation between the FDG extraction and MFR was observed in nonviable regions. CONCLUSION: As in the animal model, decreasing MFRs in viable myocardium are associated with increasing glucose extraction that likely reflects a metabolic adaptation of remodeling hibernating myocytes.

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In this study, we investigated the effect of the xanthine oxidase (XO) inhibitor, allopurinol (ALP), on cardiac dysfunction, oxidative-nitrosative stress, apoptosis, poly(ADP-ribose) polymerase (PARP) activity and fibrosis associated with diabetic cardiomyopathy in mice. Diabetes was induced in C57/BL6 mice by injection of streptozotocin. Control and diabetic animals were treated with ALP or placebo. Left ventricular systolic and diastolic functions were measured by pressure-volume system 10 weeks after established diabetes. Myocardial XO, p22(phox), p40(phox), p47(phox), gp91(phox), iNOS, eNOS mRNA and/or protein levels, ROS and nitrotyrosine (NT) formation, caspase3/7 and PARP activity, chromatin fragmentation and various markers of fibrosis (collagen-1, TGF-beta, CTGF, fibronectin) were measured using molecular biology and biochemistry methods or immunohistochemistry. Diabetes was characterized by increased myocardial, liver and serum XO activity (but not expression), increased myocardial ROS generation, p22(phox), p40(phox), p47(phox), p91(phox) mRNA expression, iNOS (but not eNOS) expression, NT generation, caspase 3/7 and PARP activity/expression, chromatin fragmentation and fibrosis (enhanced accumulation of collagen, TGF-beta, CTGF and fibronectin), and declined systolic and diastolic myocardial performance. ALP attenuated the diabetes-induced increased myocardial, liver and serum XO activity, myocardial ROS, NT generation, iNOS expression, apoptosis, PARP activity and fibrosis, which were accompanied by improved systolic (measured by the evaluation of both load-dependent and independent indices of myocardial contractility) and diastolic performance of the hearts of treated diabetic animals. Thus, XO inhibition with ALP improves type 1 diabetes-induced cardiac dysfunction by decreasing oxidative/nitrosative stress and fibrosis, which may have important clinical implications for the treatment and prevention of diabetic cardiomyopathy and vascular dysfunction.

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Doxorubicin (DOX) is a potent available antitumor agent; however, its clinical use is limited because of its cardiotoxicity. Cell death is a key component in DOX-induced cardiotoxicity, but its mechanisms are elusive. Here, we explore the role of superoxide, nitric oxide (NO), and peroxynitrite in DOX-induced cell death using both in vivo and in vitro models of cardiotoxicity. Western blot analysis, real-time PCR, immunohistochemistry, flow cytometry, fluorescent microscopy, and biochemical assays were used to determine the markers of apoptosis/necrosis and sources of NO and superoxide and their production. Left ventricular function was measured by a pressure-volume system. We demonstrated increases in myocardial apoptosis (caspase-3 cleavage/activity, cytochrome c release, and TUNEL), inducible NO synthase (iNOS) expression, mitochondrial superoxide generation, 3-nitrotyrosine (NT) formation, matrix metalloproteinase (MMP)-2/MMP-9 gene expression, poly(ADP-ribose) polymerase activation [without major changes in NAD(P)H oxidase isoform 1, NAD(P)H oxidase isoform 2, p22(phox), p40(phox), p47(phox), p67(phox), xanthine oxidase, endothelial NOS, and neuronal NOS expression] and decreases in myocardial contractility, catalase, and glutathione peroxidase activities 5 days after DOX treatment to mice. All these effects of DOX were markedly attenuated by peroxynitrite scavengers. Doxorubicin dose dependently increased mitochondrial superoxide and NT generation and apoptosis/necrosis in cardiac-derived H9c2 cells. DOX- or peroxynitrite-induced apoptosis/necrosis positively correlated with intracellular NT formation and could be abolished by peroxynitrite scavengers. DOX-induced cell death and NT formation were also attenuated by selective iNOS inhibitors or in iNOS knockout mice. Various NO donors when coadministered with DOX but not alone dramatically enhanced DOX-induced cell death with concomitant increased NT formation. DOX-induced cell death was also attenuated by cell-permeable SOD but not by cell-permeable catalase, the xanthine oxidase inhibitor allopurinol, or the NADPH oxidase inhibitors apocynine or diphenylene iodonium. Thus, peroxynitrite is a major trigger of DOX-induced cell death both in vivo and in vivo, and the modulation of the pathways leading to its generation or its effective neutralization can be of significant therapeutic benefit.

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Myocardial infarction is almost always the consequence of a thrombotic obstruction of one or more coronary arteries. We report our experience with the first 24 cases of intracoronary thrombolysis for recanalization of obstructed coronary arteries. 19 cases were successful, 1 case was partially successful and in 4 instances no reopening was observed. The amount of streptokinase used was 206 000 +/- 107 000 units, and reperfusion was achieved after 37 +/- 27.5 minutes. Recanalization of the vessel was accompanied by cessation of precordial pain and partial or complete normalization of the electrocardiogram. In one case bypass surgery was necessary because of reocclusion. Left ventricular function improvement after thrombolysis was dependent on the time-lag between occlusion and recanalization. These observations confirm others' experience that intracoronary thrombolysis appears to have favorable effects in patients with evolving myocardial infarction.

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Background In patients presenting with acute cardiac symptoms, abnormal ECG and raised troponin, myocarditis may be suspected after normal angiography. Aims To analyse cardiac magnetic resonance (CMR) findings in patients with a provisional diagnosis of acute coronary syndrome (ACS) in whom acute myocarditis was subsequently considered more likely. Methods and results 79 patients referred for CMR following an admission with presumed ACS and raised serum troponin in whom no culprit lesion was detected were studied. 13% had unrecognised myocardial infarction and 6% takotsubo cardiomyopathy. The remainder (81%) were diagnosed with myocarditis. Mean age was 45615 years and 70% were male. Left ventricular ejection fraction (EF) was 58610%; myocardial oedema was detected in 58%. A myocarditic pattern of late gadolinium enhancement (LGE) was detected in 92%. Abnormalities were detected more frequently in scans performed within 2 weeks of symptom onset: oedema in 81% vs 11% (p<0.0005), and LGE in 100% vs 76% (p<0.005). In 20 patients with both an acute (<2 weeks) and convalescent scan (>3 weeks), oedema decreased from 84% to 39% (p<0.01) and LGE from 5.6 to 3.0 segments (p¼0.005). Three patients presented with sustained ventricular tachycardia, another died suddenly 4 days after admission and one resuscitated 7 weeks following presentation. All 5 patients had preserved EF. Conclusions Our study emphasises the importance of access to CMR for heart attack centres. If myocarditis is suspected, CMR scanning should be performed within 14 days. Myocarditis should not be regarded as benign, even when EF is preserved.