Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
BMC Med ; 21(1): 71, 2023 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-36829203

RESUMO

BACKGROUND: No study evaluated the incidence of intra-stent restenosis (ISR)-related events in patients with type 2 diabetes (T2DM) and acute myocardial infarction (AMI) treated or not with sodium/glucose cotransporter 2 inhibitors (SGLT2i). METHODS: We recruited 377 patients with T2DM and AMI undergoing percutaneous coronary intervention (PCI). Among them, 177 T2DM were treated with SGLT2 inhibitors before PCI. The primary outcome was major adverse cardiovascular events (MACE) defined as cardiac death, re-infarction, and heart failure related to ISR. In patients without ISR, minimal lumen area and minimal lumen diameter were assessed by coronary CT-angiography at 1-year follow-up. RESULTS: Glycemic control was similar in SGLT2i-treated patients and never SGLT2i-users. The incidence of ISR-related MACE was higher in never SGLT2i-users compared with SGLT2i-treated patients, an effect independent of glycemic status (HR = 0.418, 95% CI = 0.241-0.725, P = 0.002) and observed also in the subgroup of patients with HbA1c < 7% (HR = 0.393, 95% CI = 0.157-0.984, P = 0.027). In patients without the event, the stent patency was greater in SGLT2i-treated patients compared with never SGLT2i-users at 1-year follow-up. CONCLUSIONS: SGLT2i treatment in T2DM is associated with a reduced incidence of ISR-related events, independently of glycemic control.


Assuntos
Reestenose Coronária , Diabetes Mellitus Tipo 2 , Infarto do Miocárdio , Intervenção Coronária Percutânea , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Diabetes Mellitus Tipo 2/complicações , Intervenção Coronária Percutânea/efeitos adversos , Reestenose Coronária/complicações , Reestenose Coronária/terapia , Infarto do Miocárdio/complicações , Resultado do Tratamento , Fatores de Risco
2.
J Card Fail ; 17(4): 309-17, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21440869

RESUMO

BACKGROUND: The aim of the study was to detect if right ventricular (RV) ejection fraction assessed by real-time 3-dimensional echocardiography (RT3DE) could predict patients with dilated cardiomyopathy (DCM) with greater functional impairment in response to cardiopulmonary exercise. METHODS AND RESULTS: Seventy chronic heart failure patients with DCM (55.5 ± 9.1 years; 48 males; 30 ischemic; New York Heart Association Class III: 48) underwent both left ventricular (LV) and RV analysis by RT3DE. Postprocessing software provided data of RT3DE systolic dyssynchrony index of 16 LV segments (systolic dyssynchrony index [SDI]) and of both LV and RV ejection fraction. Cardiac magnetic resonance was performed in a subgroup of 40 DCM patients to confirm RT3DE measurements. All the patients underwent also bicycle cardiopulmonary exercise test with evaluation of oxygen consumption (VO2) peak% (percentage of the predicted value), VE/VCO2 slope, and circulatory power (CP). Mean LV ejection fraction was 29.8 ± 4.6%. RT3DE LV SDI index was 8.4.4 ± 4.2, and RV ejection fraction was 51.3 ± 4.6%. By cardiopulmonary test, mean VO2 peak was 15.2 ± 4.4 mL·kg·min, and mean CP was 2.1 ± 0.8. By univariable analyses, significant correlations were detectable between SDI index and VO2 peak% (r = -0.56; P < .0001) and peak CP (r = -0.48; P < .0005). Also RV ejection fraction directly correlated with VO2 peak% (r = 0.58; P < .0001) and inversely with VE/VCO2 slope (r = -0.44; P < .001). By multivariable analysis, SDI index (ß coefficient = -0.46; P < .001) and 3D RV ejection fraction (ß coefficient = 0.42; P < .001) emerged as the only independent determinants of VO2 peak% during cardiopulmonary test. CONCLUSIONS: Increased LV electromechanical dyssynchrony and impaired RV function in DCM patients are independently associated with worse ability to perform aerobic exercise.


Assuntos
Cardiomiopatia Dilatada/fisiopatologia , Volume Sistólico/fisiologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Função Ventricular Direita/fisiologia , Volume Cardíaco , Cardiomiopatia Dilatada/diagnóstico por imagem , Ecocardiografia Tridimensional , Teste de Esforço/métodos , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Consumo de Oxigênio
3.
J Neuromuscul Dis ; 8(6): 979-988, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34120910

RESUMO

BACKGROUND: Late Onset Pompe Disease (LOPD) is a rare myopathy characterized by prevailing weakness of trunk and pelvic girdle muscles that causes motor disabilities. Spinal deformities have been reported unclearly on clinical examination. No study quantitatively assessed upright posture defining specific alterations of LOPD various phenotype. OBJECTIVE: Identify postural abnormalities in a homogeneous group of LOPD patients using 3D Stereophotogrammetry (St) and x-Ray (xR). METHODS: Seven LOPD siblings were recruited. They were assessed by clinical scales and, in upright posture, using xR and 3D-St with a new marker set protocol. Fourteen healthy individuals, age and sex-matched, were used as controls for St-parameters; normative xR-values were found in literature. RESULTS: LOPD patients showed a significant weakness of trunk and tibialis anterior muscles. Statistical analysis of St-parameters showed a larger ankle, knee, elbow, dorsal, S2-C7, heel-S2-C7, heel-S2-nasion angles and a lower sagittal vertical axis (SVA) than controls.xR-analysis highlighted an absence of scoliosis and a lower occipito-cervical, C2-C7 cervical and Cobb dorsal angles, and a trend to lower lumbar lordosis and SVA compared to normal values. Significant correlation was found in dorsal and lumbar angles calculated using xR-markers placed on spiny apophysis, xR-centre of vertebral bodies, Cobb-method and St-markers. CONCLUSION: This is the first quantitative study of postural abnormalities in LOPD patients using 3D-St and xR, highlighting sagittal standing alignment changes, difficult to assess to direct exam.Our new St-protocol showed a high reliability compared to xR. Further studies on larger population of LOPD might confirm the usefulness of these instrumental methods for monitoring disease course.


Assuntos
Doença de Depósito de Glicogênio Tipo II/diagnóstico por imagem , Fotogrametria/métodos , Postura/fisiologia , Radiografia/métodos , Posição Ortostática , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Doença de Depósito de Glicogênio Tipo II/fisiopatologia , Humanos , Lordose/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
4.
J Atheroscler Thromb ; 27(4): 279-302, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31723086

RESUMO

Early identification of coronary atherosclerotic pathogenic mechanisms is useful for predicting the risk of coronary heart disease (CHD) and future cardiac events. Epigenome changes may clarify a significant fraction of this "missing hereditability", thus offering novel potential biomarkers for prevention and care of CHD. The rapidly growing disciplines of systems biology and network science are now poised to meet the fields of precision medicine and personalized therapy. Network medicine integrates standard clinical recording and non-invasive, advanced cardiac imaging tools with epigenetics into deep learning for in-depth CHD molecular phenotyping. This approach could potentially explore developing novel drugs from natural compounds (i.e. polyphenols, folic acid) and repurposing current drugs, such as statins and metformin. Several clinical trials have exploited epigenetic tags and epigenetic sensitive drugs both in primary and secondary prevention. Due to their stability in plasma and easiness of detection, many ongoing clinical trials are focused on the evaluation of circulating miRNAs (e.g. miR-8059 and miR-320a) in blood, in association with imaging parameters such as coronary calcifications and stenosis degree detected by coronary computed tomography angiography (CCTA), or functional parameters provided by FFR/CT and PET/CT. Although epigenetic modifications have also been prioritized through network based approaches, the whole set of molecular interactions (interactome) in CHD is still under investigation for primary prevention strategies.


Assuntos
Biomarcadores/metabolismo , Doença das Coronárias/terapia , Prestação Integrada de Cuidados de Saúde/normas , Medicina de Precisão , Doença das Coronárias/metabolismo , Doença das Coronárias/patologia , Humanos , Prognóstico
5.
Am J Case Rep ; 21: e924704, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32936789

RESUMO

BACKGROUND Fascioliasis is a zoonotic disease caused by Fasciola hepatica (F. hepatica). This infection is associated with a broad spectrum of clinical symptoms such as fever, eosinophilia, and gastrointestinal symptoms. CASE REPORT We report a case of F. hepatica abdominal mass in the peri-pancreatic region in a 58-year-old man, returned from Venezuela. The patient developed abdominal pain, nausea, anorexia, and weakness. Radiological investigations showed hepatomegaly, as well as mild intra-hepatic and extrahepatic ductal dilatation. The increase in eosinophilia, elevated total IgE titer, and anamnestic data suggested the hypothesis of parasitic infection. The diagnosis was established by high serological titer against F. hepatica. CONCLUSIONS The development of abdominal mass, with jaundice and dilation of the biliary tract, does not always suggest the presence of heteroplasia. Systemic parasitosis represents a not negligible event, especially considering the personal history of life in endemic areas.


Assuntos
Eosinofilia , Fasciola hepatica , Fasciolíase , Dor Abdominal , Animais , Eosinofilia/diagnóstico , Fasciolíase/diagnóstico , Febre , Humanos , Masculino , Pessoa de Meia-Idade
6.
Eur J Heart Fail ; 11(1): 58-67, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19147458

RESUMO

AIMS: To evaluate whether quantification of the extent of scarred left ventricular (LV) tissue by speckle-tracking strain echo (2DSE) can predict response to cardiac resynchronization therapy (CRT) in patients with ischaemic dilated cardiomyopathy (DCM). METHODS AND RESULTS: Forty-five patients (58.3 +/- 8.3 years; 24 males) with ischaemic DCM scheduled for CRT, and 25 controls were studied. A week before implantation all the patients underwent standard Doppler echo, 2DSE, and contrast-enhanced magnetic resonance (MR). Clinical and echocardiographic evaluation was repeated 6 months after CRT. The patients were considered as responders to CRT if LV end-systolic volume decreased by 15%. In DCM patients, LV ejection fraction was 29.2 +/- 5.1%. By evaluating the 765 segments with MR, subendocardial infarct was identified in 17.0% and transmural infarct in 18.3%. With 2DSE, the average global longitudinal strain (GLS) was -23.1 +/- 3.6% in controls and -15.1 +/- 5.1% in DCM (P = 0.001). GLS showed a close correlation with total scar burden using MR (r = 0.64, P < 0.001). At follow-up, patients were subdivided into responders (n = 30; 66.7%) and non-responders (n = 15; 33.3%) to CRT. GLS was significantly different in non-responders than in responders (GLS: -10.4 +/- 5.1 in non-responders vs. -18.4 +/- 14% in responders, P < 0.001). In a multivariable analysis, GLS (P < 0.0001) and radial intraventricular dyssynchrony (P < 0.001) were powerful independent determinants of response to CRT. CONCLUSION: GLS is strongly associated with total scar burden assessed by MR, and is an excellent independent predictor of response to CRT.


Assuntos
Estimulação Cardíaca Artificial , Cardiomiopatia Dilatada/terapia , Cicatriz/diagnóstico por imagem , Ecocardiografia Doppler/métodos , Idoso , Algoritmos , Cardiomiopatia Dilatada/diagnóstico por imagem , Cicatriz/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Prognóstico , Curva ROC , Sensibilidade e Especificidade , Disfunção Ventricular Esquerda/diagnóstico por imagem
8.
Anticancer Res ; 27(6C): 4263-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18214030

RESUMO

AIM: To evaluate the role of low mechanical index (MI) contrast-enhanced sonography (CEUS) for the characterization of small hepatocellular carcinomas (HCC) in cirrhotic patients by comparing the results to ultrafast dynamic gadolinium-enhanced magnetic resonance imaging (MRI) studies. MATERIALS AND METHODS: Between September 2003 and June 2004, 73 patients (49 male and 24 female; mean age, 63 years; age range, 40-84 years) with a single liver nodule (< or =30 mm) were selected to enter into the study. CEUS and MRI studies were performed in all patients on consecutive days. All lesions were histologically confirmed after both imaging studies. CEUS was performed at low MI after i.v. administration of the contrast agent SonoVue. The enhancement pattern related to tumor hypervascularity was analyzed. The Chi-square test was used for statistical analysis. RESULTS: HCCs < or =10 mm (11 cases): On CEUS, 3/11 HCCs were hypervascular, while 8/11 were not visible (sensitivity, 27.3%; specificity, 100%; positive predictive value, 100%; negative predictive value, 55.6%). MRI studies showed a typical pattern in eight HCCs (sensitivity, 72.7%; specificity, 90.0%; positive predictive value, 88.9%; negative predictive value, 75.0%). HCCs 11-30 mm (37 cases): On CEUS, 34/37 (91.9%) HCCs were hypervascular, 2/37 avascular, and 1/37 not visible (sensitivity, 91.9%; specificity, 93.3%; positive predictive value, 97.1%; negative predictive value, 82.4%). MRI studies showed a typical pattern in 35/37 HCCs (sensitivity, 94.6%; specificity, 86.7%; positive predictive value, 94.6%; negative predictive value, 86.7%). The overall concordance between CEUS and MRI results was 75.0%. CONCLUSION: CEUS is a promising technique for the characterization of small HCCs in cirrhotic patients. It could be complementary to conventional sonography in evaluating focal liver lesions larger than 10 mm.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Meios de Contraste , Cirrose Hepática/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Imageamento por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/complicações , Feminino , Gadolínio , Humanos , Processamento de Imagem Assistida por Computador , Cirrose Hepática/complicações , Neoplasias Hepáticas/complicações , Masculino , Pessoa de Meia-Idade , Fosfolipídeos , Sensibilidade e Especificidade , Hexafluoreto de Enxofre , Ultrassonografia
9.
Am J Hypertens ; 18(12 Pt 1): 1563-9, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16364826

RESUMO

BACKGROUND: The hypothesis that left ventricular hypertrophy regression in hypertension relates to blood pressure (BP) control and to non-antihypertensive activity of some drugs was tested by comparing the effects of telmisartan and carvedilol on 24-h mean ambulatory BP and left ventricular mass (LVM) regression, measured using three-dimensional echocardiography (3-DECHO) and magnetic resonance imaging (MRI). METHODS: A total of 82 patients with mild-to-moderate hypertension and an optimal echocardiographic acoustic window were randomized to receive once-daily telmisartan 80 mg or carvedilol 25 mg for 44 weeks. RESULTS: Ten patients withdrew from the study because office diastolic BP remained >90 mm Hg. The 24-h mean ambulatory systolic/diastolic BP reductions were similar in both treatment groups (telmisartan, from 159.6 +/- 10.2/97.8 +/- 5.4 to 128.6 +/- 6.5/78.2 +/- 5.8 mm Hg; carvedilol, from 157.8 +/- 11.1/95.7 +/- 11.9 to 128.2 +/- 5.6/78.7 +/- 5.2 mm Hg). However, night-time and last 6-h mean BP reductions were nonsignificantly greater with telmisartan. Using 3-DE, telmisartan (P< .001) and carvedilol (P< .001) progressively reduced LVM index by 21.97 +/- 5.84 (15.7%) and 12.31 +/- 3.14 (9.1%) g/m2, respectively, at week 44. Similar magnitudes of reductions were observed using MRI (15.5% and 9.6%, respectively). Reductions in LVM index achieved with telmisartan were statistically superior to carvedilol (P< or = .001). CONCLUSIONS: The superior LVM regression with telmisartan versus carvedilol suggests telmisartan has a mechanism that may be beyond that of lowering BP in hypertensive patients.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Bloqueadores do Receptor Tipo 1 de Angiotensina II/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Benzimidazóis/uso terapêutico , Benzoatos/uso terapêutico , Carbazóis/uso terapêutico , Hipertensão/tratamento farmacológico , Hipertrofia Ventricular Esquerda/tratamento farmacológico , Propanolaminas/uso terapêutico , Antagonistas Adrenérgicos beta/administração & dosagem , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Pressão Sanguínea/efeitos dos fármacos , Monitorização Ambulatorial da Pressão Arterial , Carbazóis/administração & dosagem , Carvedilol , Ritmo Circadiano , Ecocardiografia Tridimensional , Feminino , Humanos , Hipertensão/diagnóstico por imagem , Hipertrofia Ventricular Esquerda/diagnóstico por imagem , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Propanolaminas/administração & dosagem , Telmisartan
10.
Chir Ital ; 57(5): 635-40, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16241096

RESUMO

It has been shown that magnetic resonance cholangiopancreatography (MRCP) has a diagnostic accuracy comparable to that of ERCP. The aim of this study was to compare the diagnostic accuracy of MRCP in patients with suspected choledocholithiasis, but with negative ultrasonography findings. Among 404 patients undergoing videolaparocholecystectomy for cholelithiasis, 48 with risk factors for coledocholithiasis were evaluated. All the patients with risk factors underwent preoperative hepatobiliary ultrasonography and MRCP. Patients were assigned to one of 2 main groups: A) patients with common bile duct stones at ultrasonography (15/48: 31%) and B) patients without evidence of common bile duct stones on ultrasonography (33/48: 69%), with B comprising two subgroups: B1) MRCP-positive for stones (7/33:21%) and B2) negative US and MRCP (26/33:79%). MRCP showed 100% sensitivity and 100% specificity. The high sensitivity of MRCP allows us to recommend a greater use of the procedure with avoidance of unnecessary ERCP, which should be reserved for therapeutic purposes only.


Assuntos
Colangiopancreatografia por Ressonância Magnética , Coledocolitíase/diagnóstico , Adulto , Idoso , Colangiopancreatografia Retrógrada Endoscópica , Coledocolitíase/complicações , Coledocolitíase/diagnóstico por imagem , Colelitíase/complicações , Colelitíase/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores de Tempo , Ultrassonografia
11.
Orphanet J Rare Dis ; 8: 159, 2013 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-24107549

RESUMO

BACKGROUND: Glycogenosis type II (GSDII or Pompe disease) is an autosomal recessive disease, often characterized by a progressive accumulation of glycogen within lysosomes caused by a deficiency of α-1,4-glucosidase (GAA; acid maltase), a key enzyme of the glycogen degradation pathway. To date, more than 326 different mutations in the GAA gene have been identified in patients with GSDII but the course of the disease is difficult to be predicted on the basis of molecular genetic changes. Studies on large informative families are advisable to better define how genetics and non genetics factors like exercise and diet may influence the clinical phenotype. METHODS AND RESULTS: In this study, we report on clinical, instrumental, and pathological features as well as on molecular analysis of a family with 10 out of 13 siblings affected by late-onset Pompe disease. Three mutations segregated in the family, two of which are novel mutations. Siblings showing a more severe phenotype were compound heterozygous for c.118C > T [p.R40X] and c.2647-7G > A [p.N882fs] on GAA, whereas, two patients showing a mild phenotype were compound heterozygous c.2647-7G > A [p.N882fs] and c.2276G > C [p.G759A] mutations. Quantitative expression analysis showed, in the patients carrying p.R40X/ p.N882fs, a significant (p 0.01) correlation between the levels of expression of the mutated allele and the age at onset of the disease. CONCLUSIONS: As far as we know, this is the largest informative family with late-onset Pompe disease described in the literature showing a peculiar complex set of mutations of GAA gene that may partially elucidate the clinical heterogeneity of this family.


Assuntos
Doença de Depósito de Glicogênio Tipo II/genética , alfa-Glucosidases/genética , Adolescente , Adulto , Densidade Óssea , Criança , Eletrofisiologia , Predisposição Genética para Doença/genética , Genótipo , Doença de Depósito de Glicogênio Tipo II/metabolismo , Doença de Depósito de Glicogênio Tipo II/patologia , Humanos , Mutação , Linhagem , Fenótipo , Adulto Jovem
12.
J Thorac Cardiovasc Surg ; 144(2): 360-9, 369.e1, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22050982

RESUMO

OBJECTIVE: Bicuspid aortic valve disease is heterogeneous with respect to valve morphology and aortopathy risk. This study searched for early imaging predictors of aortopathy in patients with a bicuspid aortic valve with right-left coronary cusp fusion, the most common morphotype. METHODS: Time-resolved magnetic resonance imaging was performed in 36 subjects with nonstenotic, nonregurgitant bicuspid aortic valves and nondilated aortas and in 10 healthy controls with tricuspid aortic valves. Sinus dimensions (diameter, width, and height), ascending tract diameters, and wall strain were measured for each sinus/leaflet unit and corresponding ascending tract area to account for asymmetries. A novel parameter, "cusp opening angle," measured the degree of valve leaflet alignment to outflow axis in systole, quantifying cusp motility. Phase-contrast magnetic resonance imaging and computational fluid dynamic models assessed flow patterns. Aortic growth rate was estimated over a follow-up period ranging from 9 to 84 months. RESULTS: The expected restriction of bicuspid aortic valve opening (conjoint cusp opening angle, 62°±5° vs 76°±3° for nonfused leaflet and 75°±3° for tricuspid aortic valve cusps; P<.001) was confirmed, and the introduced parameter reproducibly quantified this phenomenon. Phase-contrast magnetic resonance imaging demonstrated systolic flow deflection toward the right, affecting the right anterolateral ascending wall. Computational models confirmed that restricted cusp motion alone is sufficient to cause the observed flow pattern. Ascending tract wall strain was not circumferentially homogeneous in bicuspid aortic valves. In multivariable analyses, the conjoint cusp opening angle independently predicted ascending aorta diameters and growth rate (P<.001). CONCLUSIONS: In the bicuspid aortic valve commonly defined as normofunctional by echocardiographic criteria, restricted systolic conjoint cusp motion causes flow deflection. The novel measurement introduced can quantify restricted cusp opening, possibly assuming prognostic importance.


Assuntos
Doenças da Aorta/fisiopatologia , Valva Aórtica/anormalidades , Adulto , Doenças da Aorta/patologia , Valva Aórtica/patologia , Circulação Coronária/fisiologia , Feminino , Humanos , Hidrodinâmica , Imageamento por Ressonância Magnética , Masculino , Análise Multivariada , Adulto Jovem
13.
Med Eng Phys ; 32(2): 212-21, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20060766

RESUMO

An understanding of aortic root biomechanics is pivotal for the optimisation of surgical procedures aimed at restoring normal root function in pathological subjects. For this purpose, computational models can provide important information, as long as they realistically capture the main anatomical and functional features of the aortic root. Here we present a novel and realistic finite element (FE) model of the physiological aortic root, which simulates its function during the entire cardiac cycle. Its geometry is based on magnetic resonance imaging (MRI) data obtained from 10 healthy subjects and accounts for the geometrical differences between the leaflet-sinus units. Morphological realism is combined with the modelling of the leaflets' non-linear and anisotropic mechanical response, in conjunction with dynamic boundary conditions. The results show that anatomical differences between leaflet-sinus units cause differences in stress and strain patterns. These are notably higher for the leaflets and smaller for the sinuses. For the maximum transvalvular pressure value, maximum principal stresses on the leaflets are equal to 759, 613 and 603 kPa on the non-coronary, right and left leaflet, respectively. For the maximum aortic pressure, average maximum principal stresses values are equal to 118, 112 and 111 kPa on the right, non-coronary and left sinus, respectively. Although liable of further improvements, the model seems to reliably reproduce the behaviour of the real aortic root: the model's leaflet stretches, leaflet coaptation lengths and commissure motions, as well as the timings of aortic leaflet closures and openings, all matched with the experimental findings reported in the literature.


Assuntos
Aorta/anatomia & histologia , Aorta/fisiologia , Análise de Elementos Finitos , Imageamento por Ressonância Magnética , Valva Aórtica/anatomia & histologia , Valva Aórtica/fisiologia , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Modelos Anatômicos , Modelos Biológicos , Estresse Mecânico
14.
J Thorac Cardiovasc Surg ; 140(4): 890-6, 896.e1-2, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20363481

RESUMO

OBJECTIVE: Congenital bicuspid aortic valves frequently cause aortic stenosis or regurgitation. Improved understanding of valve and root biomechanics is needed to achieve advancements in surgical repair techniques. By using imaging-derived data, finite element models were developed to quantify aortic valve and root biomechanical alterations associated with bicuspid geometry. METHODS: A dynamic 3-dimensional finite element model of the aortic root with a bicuspid aortic valve (type 1 right/left) was developed. The model's geometry was based on measurements from 2-dimensional magnetic resonance images acquired in 8 normotensive and otherwise healthy subjects with echocardiographically normal function of their bicuspid aortic valves. Numeric results were compared with those obtained from our previous model representing the normal root with a tricuspid aortic valve. The effects of raphe thickening on valve kinematics and stresses were also evaluated. RESULTS: During systole, the bicuspid valve opened asymmetrically compared with the normal valve, resulting in an elliptic shape of its orifice. During diastole, the conjoint cusp occluded a larger proportion of the valve orifice and leaflet bending was altered, although competence was preserved. The bicuspid model presented higher stresses compared with the tricuspid model, particularly in the central basal region of the conjoint cusp (+800%). The presence of a raphe partially reduced stress in this region but increased stress in the other cusp. CONCLUSIONS: Aortic valve function is altered in clinically normally functioning bicuspid aortic valves. Bicuspid geometry per se entails abnormal leaflet stress. The stress location suggests that leaflet stress may play a role in tissue remodeling at the raphe region and in early leaflet degeneration.


Assuntos
Valva Aórtica/fisiopatologia , Simulação por Computador , Análise de Elementos Finitos , Cardiopatias Congênitas/fisiopatologia , Modelos Cardiovasculares , Adulto , Valva Aórtica/anormalidades , Valva Aórtica/patologia , Fenômenos Biomecânicos , Feminino , Cardiopatias Congênitas/patologia , Humanos , Imageamento Tridimensional , Cinética , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estresse Mecânico , Adulto Jovem
15.
Int J Cardiol ; 132(3): 354-63, 2009 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-18255178

RESUMO

BACKGROUND: In patients with idiopathic dilated cardiomyopathy (DCM) a more depressed left atrial (LA) booster pump function has been observed compared to ischemic patients although under similar loading conditions, and attributed both to altered LA overload and to LA larger involvement in the myopathic process. AIM OF THE STUDY: To detect by speckle-tracking two-dimensional strain (2DSE) LA systolic dysfunction in patients with either idiopathic or ischemic DCM, and to assess in these patients possible correlation between LA myocardial function and exercise capacity during cardiopulmonary test. METHODS: Three-hundred-fourteen patients (52.4+/-11.2 years) with either idiopathic (160 patients) or ischemic (154 patients) DCM underwent cardiopulmonary stress test, standard Doppler echo and 2DSE analysis of atrial longitudinal strain in the basal segments of LA septum and LA lateral wall, and in LA roof. RESULTS: The two groups were comparable for most of clinical variables. LV volumes, ejection fraction, stroke volume, and mitral valve effective regurgitant orifice were similar between the two groups. No significant differences were evidenced in Doppler transmitral inflow measurements. Also LA diameter and maximal volume were similar between the two groups. Conversely, LA active empting volume and fraction were both lower in patients with idiopathic DCM (<0.001). Peak systolic myocardial atrial strain was significantly reduced in patients with idiopathic DCM compared with ischemic DCM at the level of all the analyzed atrial segments (p<0.0001). By multivariable analysis, in the overall population, ischemic aetiology of DCM (p<0.0001) and LA volume (p<0.001) were the only independent determinants of LA lateral wall systolic strain. On the other hand, LA lateral wall systolic strain (p<0.0001) and LA volume (p<0.001) were powerful independent predictors of peak oxygen consumption during cardiopulmonary exercise testing. CONCLUSIONS: Two-dimensional strain represents a promising non-invasive technique to assess LA atrial myocardial function in patients with DCM. LA systolic deformation is more depressed in idiopathic compared with ischemic DCM, and is closely associated with functional capacity during effort. Future longitudinal studies are warranted to further our understanding of the natural history of LA myocardial function, the extent of reversibility of LA dysfunction with therapy, and the possible prognostic impact of such indexes in patients with congestive heart failure.


Assuntos
Função do Átrio Esquerdo/fisiologia , Cardiomiopatia Dilatada/fisiopatologia , Ecocardiografia/métodos , Tolerância ao Exercício/fisiologia , Adulto , Volume Cardíaco , Ecocardiografia Doppler , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Software
16.
Eur Heart J ; 28(22): 2738-48, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17959621

RESUMO

AIMS: In dilated cardiomyopathy (DCM), attenuation of left atrial (LA) booster pump function has been observed, and attributed both to altered LA loading conditions owing to left ventricular (LV) diastolic dysfunction and to LA involvement in the myopathic process. The aim of the present study was to detect LA systolic dysfunction in DCM using speckle-tracking two-dimensional strain echocardiography (2DSE), and to assess the effects of cardiac resynchronization therapy (CRT) on LA myocardial strain during 6 month follow-up. METHODS AND RESULTS: A total of 90 patients (aged, 52.4 +/- 10.2 years) with either idiopathic (n = 47) or ischaemic (n = 43) DCM underwent standard Doppler echo and 2DSE analysis of atrial longitudinal strain in the basal segments of LA septum and LA lateral wall, and in LA roof. The two groups were comparable for clinical variables (NYHA class: III in 72.2%; IV in 27.8%). LV volumes, ejection fraction, stroke volume, and mitral valve effective regurgitant orifice were similar between the two groups. No significant differences were evidenced in Doppler transmitral inflow measurements. LA diameter and maximal volume were also similar between the two groups. Conversely, LA active emptying volume and fraction were both lower in patients with idiopathic DCM. Peak systolic myocardial atrial strain was significantly compromised in patients with idiopathic DCM compared with ischaemic DCM in all the analysed atrial segments (P < 0.001). At follow-up, 64 patients (71.1%) (37 idiopathic and 27 ischaemic) were responders, and 26 (28.9%) (10 idiopathic; 16 ischaemic) were non-responders to CRT (responder: decrease of LV end-systolic volume >15%). A significant improvement in LA systolic function was obtained only in patients with ischaemic DCM responders to CRT (P < 0.001). By multivariable analysis, in the overall population, it was found that ischaemic aetiology of DCM (beta-coefficient = 0.62; P < 0.0001) and positive response to CRT (beta-coefficient = 0.42; P < 0.01) were the only independent determinants of LA lateral wall systolic strain. CONCLUSIONS: Two-dimensional strain represents a promising non-invasive technique to assess LA atrial myocardial function in patients with DCM. LA pump and reservoir function at baseline and after CRT are more depressed in idiopathic compared with ischaemic DCM patients. Future longitudinal studies are warranted to understand further the natural history of LA myocardial function, the extent of reversibility of LA dysfunction with CRT, and the possible prognostic impact of such indexes in patients with congestive heart failure.


Assuntos
Fibrilação Atrial/terapia , Estimulação Cardíaca Artificial/métodos , Cardiomiopatia Dilatada/complicações , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/fisiopatologia , Débito Cardíaco/fisiologia , Cardiomiopatia Dilatada/fisiopatologia , Estudos de Casos e Controles , Ecocardiografia Doppler/métodos , Ecocardiografia sob Estresse/métodos , Feminino , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Sístole/fisiologia
17.
AJR Am J Roentgenol ; 183(5): 1319-26, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15505297

RESUMO

OBJECTIVE: We sought to investigate the efficacy of contrast-enhanced sonography using a second-generation contrast agent for the evaluation of hepatocellular carcinoma in patients with cirrhosis by comparing the results to those obtained with contrast-enhanced helical CT. SUBJECTS AND METHODS: Between October 2002 and March 2003, 74 patients with cirrhosis (60 men and 14 women; age range, 47-80 years; mean age, 67 years) who had a single nodule of hepatocellular carcinoma were selected to be studied from a cohort of 437 patients with cirrhosis. The size range of the 74 nodules was 9-65 mm (mean, 28.2 mm). Twenty-eight (38%) were 20 mm smaller (range, 9-20 mm; mean, 16.6 mm), and 46 (62%) were larger than 20 mm (range, 21-65 mm; mean, 35.2 mm). Contrast-enhanced sonography was performed at a low mechanical index after IV administration of the contrast agent SonoVue. CT scans were obtained in all patients. The enhancement pattern related to tumor hypervascularity was analyzed. The chi-square test was used for statistical analysis. RESULTS: For the 28 hepatocellular carcinomas 20 mm or smaller, contrast-enhanced sonography showed 15 (53.6%) as hypervascular and 10 (35.7%) as avascular; three (10.7%) carcinomas were missed. On CT, 12 (42.9%) of the 28 hepatocellular carcinomas appeared hypervascular, 13 (46.4%) appeared hypovascular, and three (10.7%) were missed. For the 46 hepatocellular carcinomas larger than 20 mm, contrast-enhanced sonography showed 42 (91.3%) as hypervascular and four (8.7%) as avascular. On CT, 35 (76.1%) hepatocellular carcinomas appeared hypervascular, eight (17.4%) appeared hypovascular, and three (6.5%) were missed. Differences between CT appearance of hepatocellular carcinomas and contrast-enhanced sonographic appearance of the carcinomas were not statistically significant. Concordance between contrast-enhanced sonographic and CT appearances was observed in 61 (82.4%) of 74 cases. CONCLUSION: Contrast-enhanced sonography is similar to CT for detecting hepatocellular carcinoma hypervascularity. It could be complementary to conventional unenhanced sonography for evaluation of liver nodules.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Meios de Contraste , Cirrose Hepática/complicações , Neoplasias Hepáticas/diagnóstico por imagem , Fosfolipídeos , Hexafluoreto de Enxofre , Tomografia Computadorizada Espiral , Idoso , Idoso de 80 Anos ou mais , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/complicações , Feminino , Humanos , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/complicações , Masculino , Pessoa de Meia-Idade , Ultrassonografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA