Influence of fluid volume variations on the calculated value of the left ventricular mass measured by echocardiogram in patients submitted to hemodialysis

The left ventricular mass (LVM) measurement is of major importance for renal patients, as ventricular hypertrophy is an important prognostic index. The echo-cardiogram of the ventricular mass is larger before than it is after hemodialysis, which can confuse data interpretation. The aim of this work is to study the influence of alterations in fluid volume on the variations in measurements of ventricular mass observed during the course of a hemodialysis. Sixteen patients with chronic renal insufficiency in hemodialysis were evaluated at the Dialysis Unit of the University Hospital-UNESP, Botucatu, São Paulo State. The left ventricular mass was calculated from echocardiograms taken before and after hemodialysis and simultaneous ultra-filtration (12 patients: UF GROUP) and before and after hemodialysis isovolemic phase with sequential ultra-filtration (10 patients: ISO GROUP). Six of these patients were submitted to measurements of left ventricular mass before and after hemodialysis in both isovolemic and simultaneous ultra-filtration procedures. In the UF group, there was significant reduction in the following parameters before and after dialysis: diastolic diameter from 54.0 +/- 6.0 mm to 45.6 +/- 7.6 mm; left ventricular mass from 342 +/- 114 g to 265 +/- 117 g; and its respective index (IMVE) from 214 +/- 68 g/m(2) to 168 +/- 71 g/m(2). The ISO group showed no statistically significant variation. The behavior of the variables of six patients submitted to both observations confirm these results. In conclusion, the variations in echocardiogram measurements of the left ventricular mass relating to hemodialysis appear to be induced by alterations of the volemic condition.

Influence of the elevation of the left ventricular diastolic pressure on the values of the first temporal derivative of the ventricular pressure (dP/dt)

PURPOSE: To assess the effects of the elevation of the left ventricular end-diastolic pressure (LVEDP) on the value of the 1st temporal derivative of the ventricular pressure (dP/dt). METHODS: Nineteen anesthetized dogs were studied. The dogs were mechanically ventilated and underwent thoracotomy with parasympathetic nervous system block. The LVEDP was controlled with the use of a perfusion circuit connected to the left atrium and adjusted to the height of a reservoir. The elevation of the LVEDP was achieved by a sudden increase in the height of a reservoir filled with blood. Continuous recordings of the electrocardiogram, the aortic and ventricular pressures and the dP/dt were performed. RESULTS: Elevation of the LVEDP did not result in any variation of the heart rate (167±16.0bpm, before the procedure; 167±15.5bpm, after the procedure). All the other variables assessed, including systolic blood pressure (128±18.3mmHg and 150±21.5mmHg), diastolic blood pressure (98±16.9mmHg and 115±19.8mmHg), LVEDP (5.5±2.49 and 9.3±3.60mmHg), and dP/dt (4,855 ± 1,082 mmHg/s and 5,149±1,242mmHg/s) showed significant increases following the expansion of the ventricular cavity. Although the elevation of the dP/dt was statistically significant, 6 dogs curiously showed a decrease in the values of dP/dt. CONCLUSION: Sudden elevation of the LVEDP resulted in increased values of dP/dt; however, in some dogs, this response was not uniform.

Early echocardiographic predictors of increased left ventricular end-diastolic pressure three months after myocardial infarction in rats

Background: The objective of this study was to determine the early echocardiographic predictors of elevated left ventricular end-diastolic pressure (LVEDP) after a long follow-up period in the infarcted rat model.Material/Methods: Five days and three months after surgery, sham and infarcted animals were subjected to transthoracic echocardiography. Regression analysis and receiver-operating characteristic (ROC) curve were performed for predicting increased LVEDP 3 months after MI.Results: Among all of the variables, assessed 5 days after myocardial infarction, infarct size (OR: 0.760; CI 95% 0.563-0.900; p=0.005), end-systolic area (ESA) (OR: 0.761; Cl 95% 0.564-0.900; p=0.008), fractional area change (FAC) (OR: 0.771; CI 95% 0.574-0.907; p=0.003), and posterior wall-shortening velocity (PWSV) (OR: 0.703; CI 95% 0.502-0.860; p=0.048) were predictors of increased LVEDP. The LVEDP was 3.6 +/- 1.8 mmHg in the control group and 9.4 +/- 7.8 mmHg among the infarcted animals (p=0.007). Considering the critical value of predictor variables in inducing cardiac dysfunction, the cut-off value was 35% for infarct size, 0.33 cm(2) for ESA, 40% for FAC, and 26 mm/s for PWSV.Conclusions: Infarct size, FAC, ESA, and PWSV, assessed five days after myocardial infarction, can be used to estimate an increased LVEDP three months following the coronary occlusion.

Cerebral ischemia as initial neurological manifestation of atrial myxoma: case report

Infartos cerebrais de etiologia cardíaca são observados em cerca de 20% dos pacientes com acidente vascular cerebral isquêmico. Infarto cerebral ocorre como manifestação clínica inicial em um terço dos casos de mixoma atrial. Embora quase metade dos pacientes com mixoma atrial apresente alteração ao exame neurológico, infarto cerebral não hemorrágico é visto na tomografia computadorizada em praticamente todos os casos. Os autores apresentam o caso de uma paciente, cuja primeira manifestação clínica do mixoma atrial foi um acidente vascular cerebral isquêmico e chamam a atenção para a possibilidade de infarto cerebral silencioso em pacientes portadores de mixoma atrial.

Association between atherosclerotic aortic plaques and left ventricular hypertrophy in patients with cerebrovascular events

Background and Purpose - the purpose of this research was to evaluate whether an association exists between the presence of atherosclerotic plaque in the thoracic aorta and left ventricular hypertrophy (LVH) in patients with a cerebrovascular event.Methods - We included 116 consecutive patients ( 79 men; mean age, 62 +/- 12.4 years) with previous history of stroke or transient ischemic attack in a cross-sectional study. Transthoracic echocardiogram was performed to diagnose LVH and transesophageal echocardiogram for the detection of atheromas of the thoracic aorta. Continuous variables were analyzed by Student t or Mann-Whitney tests and categorized variables by Goodman test. From the significant association of LVH and age with atheromatous disease of the aorta, an adjustment to the multivariate logistic model was made using high blood pressure history or age as covariates. All of the statistical tests were carried out at a level of 5% significance.Results - Almost half of the patients (43.1%) presented atherosclerotic lesions in the aorta. LVH was present in 90.0% of patients with plaque and in only 30.3% of patients without plaque. Using high blood pressure as a covariate, the risk of patients with LVH presenting atherosclerotic plaque in the aorta was 18.23-fold greater than the risk for patients without LVH (95% CI, 5.68 to 58.54; P < 0.0001). Adding age into the model, the risk increased to 26.36 ( 95% CI, 7.14 to 97.30; P < 0.0001).Conclusions - LVH detected by conventional echocardiogram is associated with high risk of atherosclerotic plaque in the aorta and would be used as a criterion for indication of transesophageal echocardiography in patients with previous stroke or transient ischemic attack LVH.

Expressão antigênica em carcinomas do plexo coróide humano: relato de dois casos

Neoplasias provenientes do epitélio de revestimento do plexo coróide são inco-muns, tendo sido descritos 6 padrões morfológicos. O padrão anaplásico, também denominado carcinoma do plexo coróide, é o de menor freqüência e pode dar metastases fora do SNC. A distinção histológica desses tumores, particularmente da variedade anaplásica, com outras neoplasias primárias e metastáticas no SNC pode ser difícil. O uso de técnicas imunocitoquimicas em parafina tem-se mostrado útil no esclarecimento das linhagens tumorais. Os papilomas do plexo coróide têm, no entanto, sido objeto de controvérsia, por sua complexa expressão antigênica. Usando a técnica de imunoperoxidase (sistema avidina-biotina-peroxidase) pesquisaram-se, em dois casos da variedade anaplásica, os seguintes marcadores: proteína glial fibrilar ácida (GFAP) com anticorpo monoclonal e policlonal; ceratinas de 40-50kDa, ceratinas de 60-70kDa (callus ceratina), enolase neuronal específica (NSE) e proteína S-100, com anticorpos monoclonais. Os dois tumores mostraram positividade para NSE, proteína S-100 e ceratina de 40-50kDa; uma das duas neoplasias mostrou diferenciação glial, revelando positividade para GFAP tanto com anticorpo monoclonal quanto policlonal.

Right atrial stretch alters fore- and hind-brain expression of c-fos and inhibits the rapid onset of salt appetite

The inflation of an intravascular balloon positioned at the superior vena cava and right atrial junction (SVC-RAJ) reduces sodium or water intake induced by various experimental procedures (e.g. sodium depletion; hypovolaemia). In the present study we investigated if the stretch induced by a balloon at this site inhibits a rapid onset salt appetite, and if this procedure modifies the pattern of immunohistochemical labelling for Fos protein (Fos-ir) in the brain. Male Sprague-Dawley rats with SVC-RAJ balloons received a combined treatment of furosemide (Furo; 10 mg (kg bw)(-1)) plus a low dose of the angiotensin-converting enzyme inhibitor captopril (Cap; 5 mg (kg bw)(-1)). Balloon inflation greatly decreased the intake of 0.3 M NaCl for as long as the balloon was inflated. Balloon inflation over a 3 h period following Furo-Cap treatment decreased Fos-ir in the organum vasculosum of the lamina terminalis and the subfornical organ and increased Fos-ir in the lateral parabrachial nucleus and caudal ventrolateral medulla. The effect of balloon inflation was specific for sodium intake because it did not affect the drinking of diluted sweetened condensed milk. Balloon inflation and deflation also did not acutely change mean arterial pressure. These results suggest that activity in forebrain circumventricular organs and in hindbrain putative body fluid/cardiovascular regulatory regions is affected by loading low pressure mechanoreceptors at the SVC-RAJ, a manipulation that also attenuates salt appetite.

GROWTH HORMONE ATTENUATES MYOCARDIAL FIBROSIS IN RATS WITH CHRONIC PRESSURE OVERLOAD-INDUCED LEFT VENTRICULAR HYPERTROPHY

1. The role of growth hormone (GH) in cardiac remodelling and function in chronic and persistent pressure overload-induced left ventricular hypertrophy has not been defined. The aim of the present study was to assess short-term GH treatment on left ventricular function and remodelling in rats with chronic pressure overload-induced hypertrophy.2. Twenty-six weeks after induction of ascending aortic stenosis (AAS), rats were treated with daily subcutaneous injections of recombinant human GH (1 mg/kg per day; AAS-GH group) or saline (AAS-P group) for 14 days. Sham-operated animals served as controls. Left ventricular function was assessed by echocardiography before and after GH treatment. Myocardial fibrosis was evaluated by histological analysis.3. Before GH treatment, AAS rats presented similar left ventricular function and structure. Treatment of rats with GH after the AAS procedure did not change bodyweight or heart weight, both of which were higher in the AAS groups than in the controls. After GH treatment, posterior wall shortening velocity (PWSV) was lower in the AAS-P group than in the control group. However, in the AAS-GH group, PWSV was between that in the control and AAS-P groups and did not differ significantly from either group. Fractional collagen (% of total area) was significantly higher in the AAS-P and AAS-GH groups compared with control (10.34 +/- 1.29, 4.44 +/- 1.37 and 1.88 +/- 0.88%, respectively; P < 0.05) and was higher still in the AAS-P group compared with the AAS-GH group.4. The present study has shown that short-term administration of GH to rats with chronic pressure overload-induced left ventricular hypertrophy induces cardioprotection by attenuating myocardial fibrosis.

DNA methylation patterns of the CDHI, RARB, and SFN genes in choroid plexus tumors

Genetic and epigenetic alterations in choroid plexus tumors, a rare neuroepithelial neoplasm most frequently detected in children, are poorly characterized. Epigenetic silencing associated with aberrant CpG island methylation is one mechanism leading to the loss of tumor suppressor functions in cancer cells. Using methylation-specific polymerase chain reaction, the methylation patterns of the genes CDH1 (E-cadherin), RARB (retinoic acid receptor, beta), and SFN (stratifin; 14-3-3 sigma) were retrospectively investigated in eight choroid plexus tumors (five papillomas, two atypical papillomas, and one carcinoma), as well as in two normal cortexes obtained after autopsy from male individuals aged 6 months and 64 years. Among the six pediatric tumors, the mean age at diagnosis was 1.8 years old (range, 0.2-6) and the two adult tumors were detected in a 66-year-old man and a 45-year-old woman. A high frequency of hypermethylation was detected in CDH1 and SFN genes in tumoral and normal cortex tissues. Tumor-specific RARB hypermethylation was observed in four papillomas. Further studies are required to evaluate the role of aberrant methylation in choroid plexus tumor progression. (c) 2007 Elsevier B.V. All rights reserved.

The unequal influences of the left and right vagi on the control of the heart and pulmonary artery in the rattlesnake, Crotalus durissus

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for W' -> tb resonances with left- and right-handed couplings to fermions D0 Collaboration

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for Heavy Neutrinos and W-R Bosons with Right-Handed Couplings in a Left-Right Symmetric Model in pp Collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

End-systolic pressure-diameter relation of the left ventricle during transient and sustained elevations of blood pressure

OBJECTIVE: To assess the effect of transient and sustained variations in cardiac load on the values of the end-systolic pressure-diameter relation (ESPDR) of the left ventricle. METHODS: We studied 13 dogs under general anesthesia and autonomic blockade. Variations of cardiac loads were done by elevation of blood pressure by mechanical constriction of the aorta. Two protocols were used in each animal: gradual peaking and decreasing pressure variation, the transient arterial hypertension protocol (TAH), and a quick and 10 min sustained elevation, the sustained arterial hypertension protocol(SAH). Then, we compared the ESDR in these two situations. RESULTS: Acute elevation of arterial pressure, being it transitory or sustained, did not alter the heart frequency and increased similarly the preload and after load. However, they acted differently in end systolic pressure-diameter relation. It was greater in the SAH than TAH protocol, 21.0±7.3mmHg/mm vs. 9.2±1.2mmHg/mm (p<0.05). CONCLUSION: The left ventricular ESPDR values determined during sustained pressure elevations were higher than those found during transient pressure elevations. The time-dependent activation of myocardial contractility associated with the Frank-Starling mechanism is the major factor in inotropic stimulation during sustained elevations of blood pressure, determining an increase in the ESPDR values.

Association between left ventricular diastolic dysfunction and severity of chronic obstructive pulmonary disease

OBJECTIVES: ,,,,,The prevalence of electrocardiographic and echocardiographic abnormalities in chronic obstructive pulmonary disease according to disease severity has not yet been established. The aim of this study was to assess the prevalence of electrocardiographic and echocardiographic abnormalities in chronic obstructive pulmonary disease patients according to disease severity. ,,,, ,,,, ,,,,,METHODS: ,,,,,The study included 25 mild/moderate chronic obstructive pulmonary disease patients and 25 severe/very severe chronic obstructive pulmonary disease patients. All participants underwent clinical evaluation, spirometry and electrocardiography/echocardiography. ,,,, ,,,, ,,,,,RESULTS: ,,,,,Electrocardiography and echocardiography showed Q-wave alterations and segmental contractility in five (10%) patients. The most frequent echocardiographic finding was mild left diastolic dysfunction (88%), independent of chronic obstructive pulmonary disease stage. The proportion of right ventricular overload (p<0.05) and blockage of the anterosuperior division of the left bundle branch were higher in patients with greater obstruction. In an echocardiographic analysis, mild/moderate chronic obstructive pulmonary disease patients showed more abnormalities in segmental contractility (p<0.05), whereas severe/very severe chronic obstructive pulmonary disease patients showed a higher prevalence of right ventricular overload (p<0.05), increased right cardiac chamber (p<0.05) and higher values of E-wave deceleration time (p<0.05). Age, sex, systemic arterial hypertension, C-reactive protein and disease were included as independent variables in a multiple linear regression; only disease severity was predictive of the E-wave deceleration time [r2 = 0.26, p = 0.01]. ,,,, ,,,, ,,,,,CONCLUSION: ,,,,,Chronic obstructive pulmonary disease patients have a high prevalence of left ventricular diastolic dysfunction, which is associated with disease severity. Because of this association, it is important to exclude decompensated heart failure during chronic obstructive pulmonary disease exacerbation.