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1.
Clin Interv Aging ; 17: 1163-1171, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35957924

RESUMO

Background: In elderly patients with hip fracture, the prevalence of severe aortic stenosis (valve area <1 cm2) is close to 5%. Few studies have evaluated the prognostic role of aortic stenosis in hip fracture surgery and none has considered the effects of the postoperative setting (intensive care unit vs general ward) on clinical outcome. Purpose: The aim of the present study was to evaluate the factors affecting mortality in patients with severe aortic stenosis undergoing surgery for hip fracture. We also evaluated whether postoperative monitoring in the intensive care unit may affect the prognosis in comparison to return to the general ward after surgery. Patients and Methods: All 2274 patients referred for hip fracture to our tertiary teaching hospital between January 1 2015 and December 31 2019 were screened for the presence of severe aortic stenosis, defined by an aortic valve area <1.0 cm2. Results: The study included 66 patients (27 males, 39 females) with a mean±SD age of 85±7 years. The average time between trauma and surgery was 2.6±3 days. The mean aortic valve area was 0.74±0.15 cm2. Seven patients died during hospitalization (10.4%). Diabetes, having two or more comorbidities, a low degree of autonomy, heart failure, history of coronary artery disease, atrial fibrillation, postoperative delirium and pulmonary hypertension were associated with poorer outcome. In logistic multivariate analysis, the number of diseases and values of pulmonary artery pressure were the only independent factors related to mortality. In hospital mortality (12 and 9%, respectively) and complication rates were not statistically different between patients referred to the intensive care unit for postoperative monitoring and patients returned to the general ward after surgery. Conclusion: In patients undergoing hip fracture surgery, severe aortic stenosis is associated with high hospital mortality, and two or more comorbidities and pulmonary hypertension are associated with a worse prognosis. The postoperative setting (intensive care unit or general ward) does not affect outcome.


Assuntos
Estenose da Valva Aórtica , Implante de Prótese de Valva Cardíaca , Fraturas do Quadril , Hipertensão Pulmonar , Idoso , Idoso de 80 Anos ou mais , Estenose da Valva Aórtica/complicações , Estenose da Valva Aórtica/cirurgia , Feminino , Fraturas do Quadril/complicações , Fraturas do Quadril/cirurgia , Mortalidade Hospitalar , Humanos , Hipertensão Pulmonar/complicações , Hipertensão Pulmonar/cirurgia , Masculino , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
2.
J Am Med Dir Assoc ; 23(4): 654-659.e1, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34861226

RESUMO

OBJECTIVES: To assess the independent effect of delirium on mortality and disability after 1 year of follow-up, in consecutive older patients with hip fracture hospitalized for surgical repair. DESIGN: This is a prospective observational study. SETTING AND PARTICIPANTS: Patients aged older than 65 years consecutively admitted for hip fracture to the Trauma and Orthopedics Centre of a third-level hospital, between March and October 2014. METHODS: Patients were evaluated by a multidisciplinary team. A comprehensive geriatric assessment was performed on admission. Delirium was assessed before and after surgical repair according to the Confusion Assessment Method. Mortality and disability status were collected at 3 months and 1 year after hospital discharge. RESULTS: Of 411 patients with hip fracture, 387 (mean age 82 years, female 72%) were enrolled. Delirium was assessed in 50% of the enrolled population. Patients with delirium were older, frequently affected by dementia, severe prefracture disability, history of falls, and polypharmacy. One-year mortality was 19% in all populations, and higher in patients with delirium, although delirium did not show an independent association with mortality, in multivariable analysis. Conversely, delirium was identified as an independent prognostic factor of long-term disability (B-1.605, SE 0.211, P < .001). CONCLUSION AND IMPLICATIONS: This study identifies delirium as an independent long-term disability generator, regardless of associated clinical conditions and premorbid cognitive and functional status. This emphasises the importance of delirium prevention through a multidisciplinary approach and the potential role of systematic treatment of risk factors in reducing functional decline, even in subjects with preexistent disability and dementia. Moreover, these data call for research on rehabilitation interventions specifically targeted to these complex patients, with the aim of identifying approaches effective in reducing long-term disability. Conversely, a high level of clinical alertness is required in patients with delirium, as an appropriate treatment of acute diseases should reduce their high mortality risk.


Assuntos
Delírio , Fraturas do Quadril , Atividades Cotidianas , Idoso , Idoso de 80 Anos ou mais , Delírio/epidemiologia , Feminino , Avaliação Geriátrica/métodos , Fraturas do Quadril/cirurgia , Hospitalização , Humanos , Fatores de Risco
3.
J Emerg Med ; 40(5): 499-505, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-19217237

RESUMO

BACKGROUND: The absence of a rapidly available and sensitive diagnostic test represents an important limitation in the triage of patients with suspected stroke. OBJECTIVES: The aim of the present study was to investigate the triage accuracy of a novel test that measures blood-borne biomarkers (triage stroke panel, TSP) and to compare its accuracy with that of the Cincinnati Prehospital Stroke Scale (CPSS). METHODS: Consecutive patients with suspected stroke presenting to the Emergency Departments of three Italian hospitals underwent triage by a trained nurse according to the CPSS and had blood drawn for TSP testing. The TSP simultaneously measures four markers (B-type natriuretic peptide, D-dimer, matrix metalloproteinase-9, and S100ß) presenting a single composite result, the Multimarker Index (MMX). Stroke diagnosis was established by an expert committee blinded to MMX and CPSS results. RESULTS: There were 155 patients enrolled, 87 (56%) of whom had a final diagnosis of stroke. The area under the receiver operating characteristic (ROC) curve for CPSS was 0.77 (95% confidence interval [CI] 0.70-0.84) and that of MMX was 0.74 (95% CI 0.66-0.82) (p = 0.285). Thus, both tests, when used alone, failed to recognize approximately 25% of strokes. The area under the ROC curve of the combination of the two tests (0.86, 95% CI 0.79-0.91) was significantly greater than that of either single test (p = 0.01 vs. CPSS and p < 0.001 vs. TSP). CONCLUSIONS: In an emergency care setting, a panel test using multiple biochemical markers showed triage accuracy similar to that of CPSS. Further studies are needed before biomarkers can be introduced in the clinical work-up of patients with suspected stroke.


Assuntos
Biomarcadores/sangue , Acidente Vascular Cerebral/diagnóstico , Triagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Área Sob a Curva , Angiografia Cerebral , Serviço Hospitalar de Emergência , Feminino , Produtos de Degradação da Fibrina e do Fibrinogênio/metabolismo , Humanos , Itália , Imageamento por Ressonância Magnética , Masculino , Metaloproteinase 9 da Matriz/sangue , Pessoa de Meia-Idade , Peptídeo Natriurético Encefálico/sangue , Fatores de Crescimento Neural/sangue , Curva ROC , Análise de Regressão , Subunidade beta da Proteína Ligante de Cálcio S100 , Proteínas S100/sangue , Tomografia Computadorizada por Raios X
4.
Intern Emerg Med ; 16(2): 333-338, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32440983

RESUMO

Few information exist about incidence and prognostic significance of postoperative atrial fibrillation (POAF) in patients undergoing hip fracture surgery. In the period comprised between January 2012 and December 2016, we evaluated 3129 patients referred for hip fracture. At hospital admission 277 were in permanent atrial fibrillation and were excluded from the study. POAF was defined as symptomatic or asymptomatic AF of duration > 10 min occurring during hospitalization after hip surgery. In-hospital and 1-year outcomes of POAF patients were compared to that of an age- and sex-matched hip fracture control group. Survival rates were estimated by Kaplan-Meier curves and differences between groups compared by log-rank test. One hundred and four patients (mean age 83.7 years, men 27%) developed POAF (3.6%). Time of onset after surgery was on average 2 days after surgery. Eight POAF patients died during hospitalization. 81.7% were discharged in sinus rhythm. Patients with POAF had a longer time to surgery (3.8 ± 3.3 vs. 2.4 ± 1.6 days, p = 0.0007) and length of hospital stay (19.7 ± 10.4 vs. 14.4 ± 5.1 days p < 0.0001) in comparison to control group. Eight patients had AF recurrence during follow-up. 1-year mortality was significantly higher in POAF group in comparison to control group (39.3. vs 20.9%, p < 0.001). Postoperative atrial fibrillation in patients undergoing hip fracture surgery is associated with a longer length of hospital stay in comparison to patients who maintain stable sinus rhythm. Moreover, these patients had a significant higher mortality at 1-year follow-up.


Assuntos
Fibrilação Atrial/epidemiologia , Fraturas do Quadril/cirurgia , Complicações Pós-Operatórias/epidemiologia , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Prognóstico
5.
Sci Rep ; 11(1): 9467, 2021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33947928

RESUMO

Aim of the present study was to investigate the effects of ongoing treatment with DOACs on time from trauma to surgery and on in-hospital clinical outcomes (blood losses, need for transfusion, mortality) in patients with hip fracture. Moreover we evaluated the adherence to current guidelines regarding the time from last drug intake and surgery. In this observational retrospective study clinical records of patients admitted for hip fracture from January 2016 to January 2019 were reviewed. 74 patients were in treatment with DOACs at hospital admission. Demographic data, comorbidities and functional status before trauma were retrieved. As control group we evaluated 206 patients not on anticoagulants matched for age, gender, type of fracture and ASA score. Time to surgery was significantly longer in patients treated with DOACs (3.6 + 2.7 vs. 2.15 ± 1.07 days, p < 0.0001) and treatment within 48 h was 47% vs. 80% in control group (p < 0.0001). The adherence to guidelines' suggested time from last drug intake to surgery was 46%. Neither anticipation nor delay in surgery did result in increased mortality, length of stay or complication rates with the exception of larger perioperative blood loss (Hb levels < 8 g/dl) in DOACs patients (34% vs 9% p < 0.0001). Present results suggest that time to surgery is significantly longer in DOAC patients in comparison to controls and adherence to guidelines still limited.


Assuntos
Anticoagulantes/uso terapêutico , Fraturas do Quadril/tratamento farmacológico , Ossos Pélvicos/efeitos dos fármacos , Administração Oral , Idoso de 80 Anos ou mais , Feminino , Hemorragia/tratamento farmacológico , Humanos , Masculino , Estudos Retrospectivos
6.
J Crit Care Med (Targu Mures) ; 6(3): 146-151, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32864459

RESUMO

BACKGROUND: The prevalence of Takotsubo syndrome in hip fracture is not known. METHODS: Hip fracture patients were evaluated in a multidisciplinary unit. Patients with ECG abnormalities and increased troponin I values at the time of hospital admission were included in the study Follow-up was clinical at 30 days and by telephonic interview at one year. RESULTS: Between October 1st 2011 to September 30th 2016, 51 of 1506 patients had preoperative evidence of myocardial damage. Eight, all females, fulfilled the Mayo criteria for Takotsubo syndrome, six had no coronary lesions. Hip surgery was uneventful, and all eight were alive at thirty days, and seven of these were still alive after one year. Forty-three patients had myocardial infarction: mortality at thirty days and one year were 11% and 44% (p<0.0001, Student's t-test; log-rank test). CONCLUSION: At least 15% of patients with hip fracture and preoperative myocardial damage had Takotsubo syndrome. They were all elderly females. Contrary to myocardial infarction, Takotsubo syndrome has a favourable long term prognosis.

7.
Trauma Surg Acute Care Open ; 4(1): e000218, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30729173

RESUMO

BACKGROUND: Five to ten percent of patients with hip fracture have severe aortic valve stenosis (AS). The aim of the present investigation was to evaluate the impact of AS on early and long-term outcome after surgery for hip fracture. METHODS: 145 patients with AS and 283 consecutive patients without AS (control group) aged >70 years referred to Azienda Ospadaliera Universitaria (AOU) Careggi for hip fracture were included in the study. The endpoints were incidence of postoperative myocardial infarction, 30-day and 1-year mortality, and a composite endpoint (30-day mortality + myocardial infarction). RESULTS: 66 patients had mild, 47 moderate and 32 severe AS according to the European Society of Cardiology guidelines. 30-day mortality was 6.2% in AS and 3.1% in controls. Postoperative non-fatal myocardial infarction and composite endpoint were more frequent in AS than in the control group (8.3% vs 1.1%, p<0.001 and 14.5% vs 4.2%, p<0.001, respectively). The risk was significantly higher for patients with severe AS (28.1%). 1-year mortality in patients with moderate/severe AS was 46% in comparison with 16% in mild AS or in the control group (p<0.001). Coronary disease, atrial fibrillation, age, and aortic gradient were independent predictors of mortality in AS. DISCUSSION: AS significantly affects postoperative outcome after surgery for hip fracture. Since not infrequently AS is incidentally diagnosed during hospitalization after trauma, which should be the management in these patients after hip surgery? How many might benefit from surgical valve replacement or transcatheter aortic valve replacement? A heart team evaluation may be suggested before discharge for most of these patients. LEVEL OF EVIDENCE: IV.

8.
Materials (Basel) ; 12(11)2019 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-31159493

RESUMO

A new technology was tested to improve the cooking efficiency of the raw mixture for Portland clinker production by the use of nano-Ca(OH)2. A decrease in the free lime concentration after the firing of approximately 35% and 55% in the nano-added clinkers burned at 1350 °C and 1450 °C, respectively, with respect to the standard Portland clinkers was observed. Moreover, in the nano-added clinkers, a slight decrease in alite (C3S), of approximately 2-4 wt%, and increase in belite (C2S), of approximately 5-6 wt%, were observed. Despite these variations, the C2S and C3S abundance lies within the ranges for standard Portland clinkers. The results showed that the nano-addition leads to an increase of the raw mixtures' cooking efficiency. The relatively low energy required for the clinker firing could be used to increase the plant productivity and decrease the CO2 emissions during clinker burning. The decrease of the work index of the clinkers produced by the use of the nano-Ca(OH)2 also contributes to the energy saving during clinker grinding. Differences were also found in the pore size distribution among nano-added clinkers and the standard Portland clinker. The smallest porosities with the modal volume lying in the class of 3∙10-6 mm3 were found to increase by the use of nano-Ca(OH)2. However, the pore volumes higher than 2.0∙10-5 mm3 decreased in the nano-added clinkers.

9.
Arch Intern Med ; 166(19): 2151-6, 2006 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-17060547

RESUMO

BACKGROUND: In patients with acute pulmonary embolism, right ventricular dysfunction (RVD) on hospital admission is a predictor of adverse short-term clinical outcome. The aim of this study was to evaluate the prognostic value of RVD persistence at hospital discharge with regard to the likelihood of recurrent venous thromboembolism (VTE). METHODS: Echocardiography was used to assess RVD on admission and before hospital discharge in 301 consecutive patients with the first episode of acute pulmonary embolism occurring from January 1998 through July 2004. Right ventricular dysfunction was diagnosed in the presence of 1 or more of the following: right ventricular dilation (without hypertrophy), paradoxical septal systolic motion, and Doppler evidence of pulmonary hypertension. Patients were followed up at 2, 6, and 12 months and yearly thereafter. The primary end point was symptomatic, recurrent fatal or nonfatal VTE. RESULTS: Patients were categorized as those (1) without RVD (155 patients [51.5%]), (2) with RVD regression (RVD on admission but not at discharge; 87 patients [28.9%]), and (3) with persistent RVD (RVD on admission and at discharge; 59 patients [19.6%]). After a mean +/- SD of 3.1 +/- 2.7 years, patients with RVD persistence showed an increased risk of recurrent VTE (14 patients, 9.2% patient-years) compared with those without RVD (15 patients, 3.1% patient-years) or RVD regression (3 patients, 1.1% patient-years) (P = .001). Six of 8 deaths related to pulmonary embolism occurred in patients with RVD persistence. At multivariate analysis, adjusted by anticoagulant treatment duration, RVD persistence was an independent predictor of recurrent VTE (hazard ratio, 3.79; P<.001). CONCLUSION: Persistent RVD at hospital discharge after an acute pulmonary embolism is associated with recurrent VTE.


Assuntos
Embolia Pulmonar/complicações , Disfunção Ventricular Direita/etiologia , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/uso terapêutico , Ecocardiografia Doppler , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Embolia Pulmonar/tratamento farmacológico , Embolia Pulmonar/epidemiologia , Prevenção Secundária , Trombose Venosa/tratamento farmacológico , Trombose Venosa/epidemiologia , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/tratamento farmacológico
10.
Acad Emerg Med ; 17(1): 18-26, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20078435

RESUMO

OBJECTIVES: Echocardiography is a fundamental tool in the diagnosis of acute left ventricular heart failure (aLVHF). However, a consultative exam is not routinely available in every emergency department (ED). The authors investigated the diagnostic performance of emergency Doppler echocardiography (EDecho) performed by emergency physicians (EPs) for the diagnosis of aLVHF in patients with acute dyspnea. METHODS: A convenience sample of acute dyspneic patients was evaluated. For each patient, the Boston criteria score for heart failure was calculated, and N-terminal prohormone brain natriuretic peptide (NT-proBNP) and EDecho were contemporaneously performed. Four investigators, after a limited echocardiography course, performed EDechos and evaluated for a "restrictive" pattern on pulsed Doppler analysis of mitral inflow and reduced left ventricular (LV) ejection fraction. The final diagnosis, established after reviewing all patient clinical data except NT-proBNP and EDecho results, served as the criterion standard. RESULTS: Among 145 patients, 64 (44%) were diagnosed with aLVHF. The median time needed to perform EDecho was 4 minutes. Pulsed Doppler analysis was feasible in 125 patients (84%). The restrictive pattern was more sensitive (82%) and specific (90%) than reduced LV ejection fraction and more specific than the Boston criteria and NT-proBNP for the diagnosis of aLVHF. Considering noninterpretable values of the restrictive pattern and uncertain values ("gray areas") of Boston criteria (4 < Boston criteria score < 7) and of NT-proBNP (300 < NT-proBNP < 2,200 pg/mL) as false results, the accuracy of the restrictive pattern in the overall population was 75%, compared with accuracy of 49% for both NT-proBNP and Boston criteria. CONCLUSIONS: EDecho, particularly pulsed Doppler analysis of mitral inflow, is a rapid and accurate diagnostic tool in the evaluation of patients with acute dyspnea.


Assuntos
Ecocardiografia Doppler/normas , Insuficiência Cardíaca/diagnóstico , Peptídeo Natriurético Encefálico , Fragmentos de Peptídeos , Idoso , Idoso de 80 Anos ou mais , Dispneia/etiologia , Ecocardiografia Doppler/métodos , Feminino , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/complicações , Hospitais Universitários , Humanos , Imunoensaio , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade
11.
Am J Med ; 122(3): 257-64, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19272487

RESUMO

OBJECTIVE: To investigate the prognostic value of electrocardiography (ECG) alone or in combination with echocardiography in patients with acute pulmonary embolism and normal blood pressure. METHODS: Consecutive adult patients presenting to the emergency department at Azienda Ospedaliero-Universitaria Careggi with the first episode of pulmonary embolism were included. Patients with systolic blood pressure less than 100 mm Hg were excluded. ECG and echocardiography were performed within 1 hour from diagnosis and evaluated in a blinded fashion. Right ventricular strain was diagnosed in the presence of one or more of the following ECG findings: complete or incomplete right ventricular branch block, S1Q3T3, and negative T wave in V1-V4. The main outcome measurement was clinical deterioration or death during in-hospital stay. The association of variables with the main outcome was evaluated by multivariate Cox survival analysis. RESULTS: A total of 386 patients with proved pulmonary embolism were included in the study; 201 patients (52%) had right ventricular dysfunction according to echocardiography, and 130 patients (34%) showed right ventricular strain. Twenty-three patients (6%) had clinical deterioration or died. At multivariate survival analysis, right ventricular strain was associated with adverse outcome (hazard ratio 2.58; 95% confidence interval, 1.05-6.36) independently of echocardiographic findings. Patients with both right ventricular strain and right ventricular dysfunction (26%) showed an 8-fold elevated risk of adverse outcome (hazard ratio 8.47; 95% confidence interval, 2.43-29.47). CONCLUSION: Right ventricular strain pattern on ECG is associated with adverse short-term outcome and adds incremental prognostic value to echocardiographic evidence of right ventricular dysfunction in patients with acute pulmonary embolism and normal blood pressure.


Assuntos
Eletrocardiografia/métodos , Embolia Pulmonar/diagnóstico , Embolia Pulmonar/fisiopatologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pressão Sanguínea/fisiologia , Ecocardiografia/métodos , Feminino , Fibrinolíticos/administração & dosagem , Heparina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/química , Prognóstico , Embolia Pulmonar/diagnóstico por imagem , Embolia Pulmonar/tratamento farmacológico , Troponina I/análise , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/fisiopatologia , Adulto Jovem
12.
Hypertension ; 40(2): 179-85, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12154110

RESUMO

Renal endothelin-1 participates in sodium and water handling, and its urinary excretion is increased in sodium-retentive states. We compared the cortical and medullary renal expression of prepro-endothelin-1, endothelin-converting enzyme-1, and endothelin type A and type B receptors in patients who underwent nephrectomy after normal (108 mmol/d NaCl; n=6) or low (20 mmol/d NaCl; n=6) sodium diet and investigated whether sodium exerts a direct role on endothelin receptor binding in vitro. With normal sodium diet prepro-endothelin-1 mRNA was 3-fold higher in renal medulla than in cortex (P<0.01), whereas endothelin-converting enzyme-1 mRNA was equally distributed. Endothelin-1 receptor density was 2-fold higher in renal medulla than in cortex (P<0.05). Type B was the main receptor subtype in both regions. In the renal cortex, low sodium diet caused a 194% increase in prepro-endothelin-1 mRNA (P<0.05), whereas endothelin-converting enzyme-1 type B and type A receptors remained unchanged. In contrast, in the renal medulla the increase in prepro-endothelin-1 mRNA (+30%, P<0.05) was associated with a selective increase in type B receptor for both mRNA expression (+37%, P<0.05) and binding density (+55%, P<0.05). Increasing in vitro sodium concentrations between 154 and 308 mmol/L significantly enhanced type B receptor density (P<0.05) and affinity (P<0.05). In conclusion, during low sodium diet, renal prepro-endothelin-1 synthesis increases mainly in the renal cortex (where no changes in receptors occur), whereas type B receptor is selectively enhanced in the renal medulla. The range of sodium concentrations that are physiologically present in vivo in the renal medulla selectively modulate type B receptor density and affinity.


Assuntos
Medula Renal/efeitos dos fármacos , Receptores de Endotelina/metabolismo , Cloreto de Sódio na Dieta/administração & dosagem , Sódio/metabolismo , Ácido Aspártico Endopeptidases/genética , Ligação Competitiva , Endotelina-1/metabolismo , Enzimas Conversoras de Endotelina , Endotelinas/genética , Feminino , Humanos , Radioisótopos do Iodo , Córtex Renal/efeitos dos fármacos , Córtex Renal/metabolismo , Medula Renal/metabolismo , Masculino , Metaloendopeptidases , Pessoa de Meia-Idade , Precursores de Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ensaio Radioligante , Receptor de Endotelina A , Receptor de Endotelina B , Receptores de Endotelina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
13.
J Mol Cell Cardiol ; 34(11): 1491-500, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12431448

RESUMO

UNLABELLED: The role of angiotensin II in pressure overload is still debated because notwithstanding its effects on myocyte contractility angiotensin II is not an obligatory factor for the development of hypertrophy. To define the role of angiotensin II in acute pressure overload we studied the effects of AT1 blockade (valsartan 80mg per day) on myocardial contractility, cardiac growth factor gene expression, and myocardial hypertrophy in aortic banded (60mmHg) pigs. Acute pressure overload caused an abrupt reduction of myocardial contractility, measured by the end-systolic stiffness constant, and a sharp increase in end-systolic stress which rapidly normalized (within 12h) in the placebo group. In AT1-blocked animals end-systolic stiffness constant remained significantly depressed up to 24h and end-systolic stress was still elevated up to 48h (both P<0.05 vs placebo). In both groups confocal microscopy revealed that granular staining of angiotensin II in cardiomyocyte cytoplasm disappeared after 30min of pressure overload. AT1 blockade abolished following cardiac overexpression of angiotensinogen and endothelin-1 genes as shown in RT-PCR studies and the consequent angiotensin II and endothelin-1 release in the coronary circulation. Conversely, insulin-like growth factor-I and ACE mRNA overexpression, as well as the onset of left ventricular mass increase, were not significantly affected by AT1 blockade. IN CONCLUSION: (1) mechanical stress releases preformed angiotensin II from myocyte in vivo; (2) the AT1 blockade abolishes cardiac angiotensin II and endothelin-1 production with delayed recovery of myocardial contractility; whereas (3) the overexpression of insulin-like growth factor-I gene and the development of myocardial hypertrophy are not angiotensin II-mediated effects.


Assuntos
Angiotensina II/metabolismo , Angiotensinogênio/biossíntese , Endotelina-1/biossíntese , Regulação da Expressão Gênica , Coração/metabolismo , Miocárdio/metabolismo , Receptores de Angiotensina/fisiologia , Valina/análogos & derivados , Antagonistas de Receptores de Angiotensina , Angiotensinogênio/genética , Animais , Estenose da Valva Aórtica/fisiopatologia , Cateterismo Cardíaco , Citoplasma/química , Modelos Animais de Doenças , Endotelina-1/genética , Fator de Crescimento Insulin-Like I/biossíntese , Fator de Crescimento Insulin-Like I/genética , Microscopia Confocal , Miocárdio/citologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Receptor Tipo 1 de Angiotensina , Sistema Renina-Angiotensina/fisiologia , Estresse Mecânico , Suínos , Sístole , Tetrazóis/farmacologia , Valina/farmacologia , Valsartana
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