Navegando por Palavras-chave "cardiac output"
Agora exibindo 1 - 6 de 6
Resultados por página
Opções de Ordenação
- ItemSomente MetadadadosEffects of chronic anabolic steroid treatment on tonic and reflex cardiovascular control in male rats(Elsevier B.V., 2005-01-01) Beutel, A.; Bergamaschi, C. T.; Campos, R. R.; Universidade Federal de São Paulo (UNIFESP)The aim of this study was to analyze the cardiovascular effects of chronic stanozolol administration in male rats. the rats were randomly assigned to one of three groups: (1) control (n=12), (2) chronic treatment with low dose of stanozolol (LD, n = 18, 5 mg/kg week) and; (3) treatment with high dose of stanozolol (HD, n = 28, 20 mg/kg week). Mean arterial pressure (MAP) was higher in both HD (128 +/- 2.2 mmHg) and LD (126 +/- 2.5 mmHg) than control (116 2 mmHg). the LD group showed an increase in cardiac output (control 121 +/- 2.5, LD 154 +/- 5.9 ml/min), whereas in the HD group total peripheral resistance increased (control 1.03 +/- 0.07, HD 1.26 +/- 0.07 mmHg/ml/min). Acute sympathetic blockade caused a similar decrease in MAP in all groups. in conscious rats, the baroreflex index for bradyeardia (control -3.7 +/- 0.4, LD -2.0 +/- 0.1 beat/mmHg) and tachycardia (control -3.6 +/- 0.3, LD -4.7 +/- 0.2 beat/mmHg) responses changed only in the LD group. Cardiac hypertrophy was observed in both treated groups (P < 0.05). in conclusion, hypertension with differential hemodynamic changes and alterations in the reflex control in heart rate is seen at different stanozolol doses, which may be important variables in the cardiovascular effects of anabolic steroids. (c) 2004 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosEvaluation of cerebral electrical activity and cardiac output after patent ductus arteriosus ligation in preterm infants(Nature Publishing Group, 2013-11-01) Leslie, A. T. F. S. [UNIFESP]; Jain, A.; EL-Khuffash, A.; Keyzers, M.; Rogerson, S.; McNamara, P. J.; Universidade Federal de São Paulo (UNIFESP); Univ Toronto; Rotunda Hosp; Univ Melbourne; Hosp Sick ChildrenOBJECTIVE: To characterize and investigate the relationship between systemic blood flow and pre- and postoperative cerebral electrical activity in preterm neonates undergoing patent ductus arteriosus (PDA) ligation.STUDY DESIGN: A prospective observational study was conducted in 17 preterm neonates undergoing PDA ligation. All infants had amplitude-integrated electroencephalography (aEEG) recorded continuously from 4 h preoperatively to 24 h postoperatively. Targeted neonatal echocardiography was performed to evaluate myocardial performance and systemic blood flow at four sequential time points: preoperatively; 1, 8 and 24 h postoperatively.RESULT: PDA ligation was followed by a fall in the lower border of the aEEG trace lower left ventricular output, but recovery of diastolic flow in the middle cerebral artery. Altered lower margin was associated with gestational age and PDA diameter on univariate analysis, but not with low cardiac output.CONCLUSION: PDA ligation was associated with altered cerebral electrical activity, although these changes were not related to low cardiac output state.
- ItemSomente MetadadadosHaemodynamic effects of proportional assist ventilation during high-intensity exercise in patients with chronic obstructive pulmonary disease(Wiley-Blackwell, 2010-11-01) Carrascossa, Claudia R. [UNIFESP]; Oliveira, Cristino C. [UNIFESP]; Borghi-Silva, Audrey [UNIFESP]; Ferreira, Eloara M. V. [UNIFESP]; Maya, Joyce [UNIFESP]; Queiroga, Fernando [UNIFESP]; Berton, Danilo C. [UNIFESP]; Nery, Luiz E. [UNIFESP]; Alberto Neder, J. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Universidade Federal de São Carlos (UFSCar)Background and objective: Proportional assist ventilation (PAV) has been proposed as a more physiological modality of non-invasive ventilation, thereby reducing the potential for deleterious cardio-circulatory effects during exercise, in patients with COPD. We therefore evaluated whether PAV modulates the kinetic and 'steady-state' haemodynamic responses to exercise in patients with moderate-to-severe COPD.Methods: Twenty patients underwent constant-load (75-80% peak work rate) cycle ergometer exercise testing to the limit of tolerance (T(lim)), while receiving PAV or breathing spontaneously. Stroke volume (SV), heart rate (HR) and cardiac output (CO) were monitored by impedance cardiography.Results: Compared with unassisted breathing, PAV increased T(lim) in 8/20 patients (median improvement 113% (range 8 to 212) vs -20% (range -40 to -9)). PAV had no significant effects on 'steady-state' haemodynamic responses either in patients with or those without increased T(lim) (P > 0.05). However, at the onset of exercise, SV kinetics were slowed with PAV, in 13/15 patients with analysable data. HR dynamics remained unaltered or failed to accelerate sufficiently in nine of these patients, thereby slowing CO kinetics (T(1/2) 61 s (range 81-30) vs 89 s (range 100-47)). These deleterious effects were not, however, associated with PAV-induced changes in T(lim) (P > 0.05).Conclusions: PAV slowed the SV and CO kinetics at the onset of high-intensity exercise in selected patients with moderate-to-severe COPD. However, these adverse effects of PAV disappeared during the stable phase of exercise, and were not related to the ergogenic potential of PAV in this patient population.
- ItemSomente MetadadadosHeart stroke volume, cardiac output, and ejection fraction in 265 normal fetus in the second half of gestation assessed by 4D ultrasound using spatio-temporal image correlation(Informa Healthcare, 2011-09-01) Simioni, Christiane [UNIFESP]; Machado Nardozza, Luciano Marcondes [UNIFESP]; Araujo Junior, Edward [UNIFESP]; Rolo, Liliam Cristine [UNIFESP]; Zamith, Marina [UNIFESP]; Caetano, Ana Carolina [UNIFESP]; Moron, Antonio Fernandes [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objectives. the aim of this study was to establish nomograms for fetal stroke volume (SV), cardiac output (CO), and ejection fraction (EF) using four-dimensional ultrasound with spatio-temporal image correlation (STIC) modality.Methods. the fetal heart was scanned using STIC modality, starting with classic four-chamber view plane, during fetal quiescence with abdomen uppermost, at an angle of 20-30 degrees, without color Doppler flow mapping. in post-processing virtual organ, computer-aided analysis technique was used to obtain a sequence of six sections of each ventricular volume in end-systolic volume (ESV) and end-diastolic volume (EDV). the SV (SV = EDV-ESV), CO (CO = SV x fetal heart rate), and EF (EF = SV/EDV) for each ventricle were then calculated. Intra- and interobserver agreement were then calculated.Results. Two hundred sixty-five fetuses, ranging in gestational age (GA) from 20 to 34(+6) weeks, were included in the study. the left and right SV and CO increased exponentially with gestation and EF remained fairly stable through gestational. Mean left and right SV increased from 0.211 ml and 0.220 ml at 20 weeks to 1.925 ml and 2.043 ml, respectively, at 34 weeks. Mean left and right CO increased from 30.25 ml/min and 31.52 ml/min at 20 weeks to 268.49 ml/min and 287.80 ml/min, respectively, at 34 weeks. Both left and right mean EF remained constant at around 0.63 with advancing GA. Nomograms were created for LSV, RSV, LCO, RCO, LEF, and REF vs. gestational age. Intra- and interobserver agreement reached 95%.Conclusions. Four-dimensional ultrasound using STIC represents a simple and reproducible method for estimating fetal cardiac function. STIC seems to overcome many of the pitfalls of conventional ultrasound methods and has the potential to become the method of choice.
- ItemSomente MetadadadosRisk factors for decreased cardiac output after coronary artery bypass grafting: a prospective cohort study(Sage Publications Ltd, 2017) Santos, Eduarda Ribeiro dos [UNIFESP]; Lopes, Camila Takao [UNIFESP]; Maria, Vera Lúcia Regina [UNIFESP]; Barros, Alba Lucia Bottura Leite de [UNIFESP]Background: No previous study has investigated the predictive risk factors of the nursing diagnosis of risk for decreased cardiac output after coronary artery bypass grafting (CABG). Aims: This study aimed to identify the predictive risk factors of the nursing diagnosis of risk for decreased cardiac output after CABG. Methods: This was a prospective cohort study performed at a cardiac university hospital in SAo Paulo, Brazil and 257 adult patients undergoing CABG were included. Potential risk factors for low cardiac output in the immediate post-operative period were investigated using the patients' medical records. Univariate analysis and logistic regression were used to identify the predictive risk factors of decreased cardiac output. The area under the receiver operating characteristic curve was calculated as a measure of accuracy. The variables that could not be analysed through logistic regression were analysed through Fisher's exact test. Results: One hundred and ninety-five patients had low cardiac output in the immediate post-operative period. The predictive risk factors included age 60 years, decreased left ventricle ejection fraction, not using the radial artery graft, positive fluid balance and post-operative arrhythmia that differed from the pre-operative arrhythmia. This model predicted the outcome with a sensitivity of 62.9%, a specificity of 87.2% and an accuracy of 81.5%. The variables analysed through Fisher's exact test included heart failure, re-exploration and bleeding-related re-exploration. Conclusions: The predictive risk factors for the nursing diagnosis of risk for decreased cardiac output after CABG were found. These results can be used to direct nurses in patient monitoring, staff training and nursing team staffing.
- ItemSomente MetadadadosSignal-morphology impedance cardiography during incremental cardiopulmonary exercise testing in pulmonary arterial hypertension(Wiley-Blackwell, 2012-09-01) Ferreira, Eloara M. [UNIFESP]; Ota-Arakaki, Jaquelina S. [UNIFESP]; Barbosa, Priscila B. [UNIFESP]; Siqueira, Ana Cristina B. [UNIFESP]; Bravo, Daniela M. [UNIFESP]; Kapins, Carlos Eduardo B. [UNIFESP]; Silva, Celia Maria C. [UNIFESP]; Nery, Luiz Eduardo [UNIFESP]; Alberto Neder, J. [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Background Haemodynamic responses to exercise are related to physical impairment and worse prognosis in patients with pulmonary arterial hypertension (PAH). It is clinically relevant, therefore, to investigate the practical usefulness of non-invasive methods of monitoring exercise haemodynamics in this patient population. Methods Using a novel impedance cardiography (ICG) approach that does not require basal impedance estimations and relies on a morphological analysis of the impedance signal (Signal-Morphology-ICG (TM)), stroke volume (SV) and cardiac index (CI) were evaluated in 50 patients and 21 age-matched controls during a ramp-incremental cardiopulmonary exercise testing. Results Technically unacceptable readings were found in 12 of 50 (24%) patients. in the remaining subjects, early decrease (N = 9) or a plateau in SV (N = 8) and Delta (peak-unloaded exercise) SV <10 ml were markers of more advanced PAH (P<0.05). Delta CI = 1.5-fold and early estimated lactate threshold were the only independent predictors of a severely reduced peak oxygen uptake ((V) over dotO(2)) in patients (R-2 = 0.71, P<0.001). the finding of Delta CI = 1.5-fold plus peak (V) over dot O-2 < 50% predicted was associated with a number of clinical and functional markers of disease severity (P<0.001). in addition, abnormal SV responses and Delta CI = 1.5-fold were significantly related to 1-year frequency of PAH-related adverse events (death and balloon atrial septostomy, N = 8; P<0.05). Conclusions Qualitative and semi-quantitative signal-morphology impedance cardiography (TM) (PhysioFlow (TM)) during incremental exercise provided clinically useful information to estimate disease severity and short-term prognosis in patients with PAH in whom acceptable impedance signals could be obtained.