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1.
Osteoarthritis Cartilage ; 23(10): 1704-12, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26067517

RESUMO

OBJECTIVE: The purpose of this study is to evaluate the ability of machine learning to discriminate between magnetic resonance images (MRI) of normal and pathological human articular cartilage obtained under standard clinical conditions. METHOD: An approach to MRI classification of cartilage degradation is proposed using pattern recognition and multivariable regression in which image features from MRIs of histologically scored human articular cartilage plugs were computed using weighted neighbor distance using compound hierarchy of algorithms representing morphology (WND-CHRM). The WND-CHRM method was first applied to several clinically available MRI scan types to perform binary classification of normal and osteoarthritic osteochondral plugs based on the Osteoarthritis Research Society International (OARSI) histological system. In addition, the image features computed from WND-CHRM were used to develop a multiple linear least-squares regression model for classification and prediction of an OARSI score for each cartilage plug. RESULTS: The binary classification of normal and osteoarthritic plugs yielded results of limited quality with accuracies between 36% and 70%. However, multiple linear least-squares regression successfully predicted OARSI scores and classified plugs with accuracies as high as 86%. The present results improve upon the previously-reported accuracy of classification using average MRI signal intensities and parameter values. CONCLUSION: MRI features detected by WND-CHRM reflect cartilage degradation status as assessed by OARSI histologic grading. WND-CHRM is therefore of potential use in the clinical detection and grading of osteoarthritis.


Assuntos
Algoritmos , Cartilagem Articular/patologia , Processamento de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Osteoartrite do Joelho/patologia , Reconhecimento Automatizado de Padrão/métodos , Imagem de Difusão por Ressonância Magnética , Humanos , Análise dos Mínimos Quadrados , Modelos Lineares , Imageamento por Ressonância Magnética , Análise Multivariada , Osteoartrite do Joelho/diagnóstico
3.
J Am Coll Cardiol ; 26(4): 887-94, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7560613

RESUMO

OBJECTIVES: The prognostic value of dipyridamole echocardiography was assessed in patients with chronic coronary artery disease and preserved left ventricular function. BACKGROUND: Few data are available on the prognostic value of dipyridamole echocardiography in patients with a low risk of cardiac events. METHODS: Two hundred sixty-eight consecutive patients with stable, proven or suspected coronary artery disease and ejection fraction > or = 0.40 underwent high dose (up to 0.84 mg/kg body weight) dipyridamole echocardiography. In 204 patients definite exercise electrocardiographic (ECG) results were also available. RESULTS: During a mean (+/- SD) follow-up period of 16 +/- 8 months (range 6 to 36), 33 spontaneous events occurred: 15 "hard" events (cardiac death [n = 6], myocardial infarction [n = 9]) and 18 "soft" events (unstable angina). Events occurred more frequently in patients with positive findings on dipyridamole echocardiography (59% vs. 3%, p < 0.001; hard events 24% vs. 2%, p < 0.01). A positive response at the low dose (up to 0.56 mg/kg) identified patients with a high incidence of hard events (7 of 16 patients, sensitivity 50%, specificity 96%). In patients with an exercise ECG, a comparable sensitivity for cardiac events was found (89% vs. 93%, p = NS), but dipyridamole echocardiography was more specific (91% vs. 61%, p < 0.01). A positive response on the low work load exercise ECG (< 8 min) and a positive response to low dose dipyridamole echocardiography had similar accuracy (82% vs. 90%, p = NS). Cox analysis identified dipyridamole echocardiography as the best predictor of cardiac events (odds ratio [OR] 20.9, 95% confidence interval [CI] 10.8 to 37.9); the highest risk of hard events was found in patients with a positive response to low dose dipyridamole echocardiography (OR 25.4, 95% CI 12.2 to 54.1). CONCLUSIONS: In patients with chronic coronary artery disease and a low incidence of cardiac events, dipyridamole echocardiography was effective in prognostic stratification, and positive low work load exercise ECG results were a reliable predictor of subsequent events. Consequently, dipyridamole echocardiography should be considered a complementary tool in the presence of high work load positivity or ambiguous exercise ECG results.


Assuntos
Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/epidemiologia , Dipiridamol , Ecocardiografia/métodos , Vasodilatadores , Doença das Coronárias/diagnóstico , Eletrocardiografia , Teste de Esforço , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Modelos de Riscos Proporcionais , Fatores de Risco , Sensibilidade e Especificidade , Fatores de Tempo , Função Ventricular Esquerda/fisiologia
4.
J Am Coll Cardiol ; 29(2): 254-60, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9014975

RESUMO

OBJECTIVES: The aim of this multicenter, multinational, prospective, observational study was to assess the relative value of myocardial viability and induced ischemia early after uncomplicated myocardial infarction. BACKGROUND: Dobutamine-atropine stress echocardiography allows evaluation of rest function (at baseline), myocardial viability (at low dose) and residual ischemia (peak dose, up to 40 micrograms with atropine up to 1 mg) in one test. METHODS: Dobutamine-atropine stress echocardiography was performed 12 +/- 5 days (mean +/- SD) after a first uncomplicated acute myocardial infarction in 778 patients (677 men; mean age 58 +/- 10 years) with technically satisfactory rest echocardiographic study results. Patients were followed-up for 9 +/- 7 months. RESULTS: Dobutamine-atropine stress echocardiographic findings were positive for myocardial ischemia in 436 of patients (56%) and negative in 342 (44%). During follow-up, there were 14 cardiac-related deaths (1.8% of the total cohort), 24 (2.9%) nonfatal myocardial infarctions and 63 (8%) hospital readmissions for unstable angina. One hundred seventy-four patients (22%) underwent coronary revascularization (bypass surgery or coronary angioplasty). Spontaneous events occurred in 61 of 436 patients with positive and 40 of 342 patients with negative findings on dobutamine-atropine stress echocardiography (14% vs. 12%, p = 0.3). When only spontaneously occurring events were considered, the most important predictor was myocardial viability (chi-square 9.7). Using the Cox proportional hazards model, only the presence of myocardial viability (hazard ratio [HR] 2.0, p < 0.002) and age (HR 1.03, p < 0.001) were predictive of spontaneously occurring events. When only hard cardiac events were considered, age was the strongest predictor (chi-square 3.6, p = 0.056), followed by wall motion score index (WMSI) at peak dose (chi-square 3.3, p = 0.06) and remote ischemia (chi-square 2.25, p = 0.1). When cardiac death was considered, WMSI at peak dose was the best predictor (HR 9.2, p < 0.0001). CONCLUSIONS: During dobutamine stress, echocardiographic recognition of myocardial viability is more prognostically important than echocardiographic recognition of myocardial ischemia for predicting unstable angina, whereas WMSI at peak stress was the best predictor of cardiac-related death. Different events can be recognized with different efficiency by various stress echocardiographic variables.


Assuntos
Cardiotônicos , Dobutamina , Ecocardiografia , Infarto do Miocárdio/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Angina Instável/diagnóstico por imagem , Angina Instável/terapia , Angioplastia Coronária com Balão , Atropina , Sobrevivência Celular , Ponte de Artéria Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/patologia , Infarto do Miocárdio/terapia , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos
5.
Minerva Cardioangiol ; 53(4): 313-20, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16177675

RESUMO

AIM: Aim of the study was to evaluate if brain natriuretic peptide (BNP) levels, a cardiac neurohormone well correlated with prognosis in chronic heart failure (CHF), are associated with enhanced ventilatory response to exercise, in ambulatory patients with intermediate peak oxygen uptake (PVO2). METHODS: Resting BNP was measured in 129 consecutive stable CHF patients with mild to moderate heart failure (90% New York Heart Association (NYHA) class II or III) and intermediate (10-18 mL/kg/min) PVO2, assessed during cardiopulmonary exercise test. Mean (SD) left ventricular ejection fraction (EF) and pulmonary systolic pressure (PAP) were 41 +/- 3% and 47 +/- 14 mmHg, respectively. The enhanced ventilatory response to exercise (EVR) was assessed as a slope of the relation between minute ventilation and carbon dioxide production (VE/VCO2 slope) > 35. RESULTS: Thirty-three over 129 patients (26%) had EVR. Mean BNP plasma level was 394 +/- 347 pg/mL. A significant correlation between BNP and EVR (r = 0.310; p < 0.01), was observed. In the logistic multivariate model, a BNP plasma level > 100 pg/mL had an independent predictive value for EVR (95% IC 1.68 to 10.5, Odds Ratio 4.23, p = 0.02). We found a significant correlation between BNP and PAP (r = 0.390; p < 0.001), and between PAP and EVR (r = 0.511; p < 0.01). CONCLUSIONS: In CHF patients with intermediate PVO2, plasma BNP is clearly related to the enhanced ventilatory response to exercise. In this subset, BNP levels could represent an effective alternative tool for the clinical assessment in patients with unreliable cardiopulmonary exercise test.


Assuntos
Teste de Esforço , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/fisiopatologia , Peptídeo Natriurético Encefálico/sangue , Idoso , Doença Crônica , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Ventilação Pulmonar , Reprodutibilidade dos Testes
6.
Am J Med ; 110(5): 361-9, 2001 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-11286950

RESUMO

PURPOSE: Although coronary artery disease is a frequent cause of left bundle branch block, the prognostic value of myocardial ischemia in patients with this conduction abnormality has not been defined. We investigated the value of pharmacologic stress echocardiography in risk stratification of patients with left bundle branch block. PATIENTS AND METHODS: Three hundred eighty-seven patients [230 men and 157 women, mean (+/- SD) age, 64 +/- 9 years] with complete left bundle branch block on the resting electrocardiogram underwent dobutamine (n = 217) or dipyridamole (n = 170) stress echocardiography to evaluate suspected or known coronary artery disease. A summary wall motion score (on a one to four scale) was calculated. The primary end points were cardiac death and nonfatal myocardial infarction. RESULTS: A positive echocardiographic result (evidence of ischemia) was detected in 109 (28%) patients. During a mean follow-up of 29 +/- 26 months, there were 21 cardiac deaths and 20 myocardial infarctions, 63 patients underwent coronary revascularization, and 1 patient received a heart transplant. In a multivariate analysis, four clinical and echocardiographic variables were associated with increased risk of cardiac death: resting wall motion score index [hazard ratio (HR) = 7.5 per unit; 95% confidence interval (CI), 2.8 to 20; P = 0.001], previous myocardial infarction (HR = 2.9; 95% CI, 1.1 to 7.3; P = 0.02), diabetes (HR = 2.7; 95% CI, 1.1 to 6.6; P = 0.03), and the change in wall motion score index from rest to peak stress (HR = 3.0 per unit; 95% CI, 1.0 to 8.6; P = 0.04). The 5-year survival was 77% in the ischemic group and 92% in the nonischemic group (P = 0.02). Four variables were associated with increased risk of cardiac death or infarction: previous myocardial infarction (HR = 3.4; 95% CI, 1.7 to 6.8; P = 0.0005), diabetes (HR = 2.4; 95% CI, 1.2 to 4.6; P = 0.01), resting wall motion score index (HR = 2.2 per unit; 95% CI, 1.1 to 4.1; P = 0.02), and positive echocardiographic result (HR = 2.2; 95% CI, 1.1 to 4.5; P = 0.03). The 5-year infarction-free survival was 60% in the ischemic group and 87% in the nonischemic group (P < 0.0001). Stress echocardiography significantly improved risk stratification in patients without previous myocardial infarction (P = 0.0001), but not in those with previous myocardial infarction (P = 0.08). In particular, it provided additional value over clinical and resting echocardiographic findings in predicting cardiac events among patients without previous infarction. CONCLUSIONS: Myocardial ischemia during pharmacologic stress echocardiography is a strong prognostic predictor in patients with left bundle branch block, particularly in those without previous myocardial infarction.


Assuntos
Agonistas Adrenérgicos beta/efeitos adversos , Bloqueio de Ramo/diagnóstico por imagem , Dobutamina/efeitos adversos , Ecocardiografia , Isquemia Miocárdica/induzido quimicamente , Idoso , Bloqueio de Ramo/mortalidade , Ecocardiografia/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Valor Preditivo dos Testes , Prognóstico , Risco
7.
Am Heart J ; 142(4): E5, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11579369

RESUMO

BACKGROUND: beta-Blockers improve clinical outcome after acute myocardial infarction (AMI), but few data are available on their effectiveness in preventing left ventricular remodeling. The aim of the study was to assess the relative effects of captopril, metoprolol, and their combination on left ventricular remodeling after uncomplicated AMI. METHODS: Two hundred fifty consecutive patients with a first AMI were randomly allocated to receive for 6 months captopril (up to 75 mg/d, group 1), metoprolol (up to 200 mg/d, group 2), or both (group 3) starting within 24 hours from symptom onset. Of these, 130 patients (group 1, 46; group 2, 47; group 3, 37) completed the study; all patients underwent 2-dimensional echocardiography at baseline and after 2 weeks and 3 and 6 months from AMI. RESULTS: At 6 months, in comparison with baseline values, left ventricular end-diastolic area index (LVEDI) significantly increased in group 3 (P =.013) and wall motion score index significantly decreased in group 1 (P =.038). At any follow-up evaluation, the covariance analysis showed significantly greater interval changes in LVEDI in group 3 than in group 1 (P =.0077 at 2 weeks, P =.0108 at 3 months, and P = 0.0155 at 6 months). No significant differences were observed between group 1 and group 2 and between group 2 and group 3. CONCLUSIONS: After uncomplicated first AMI, early and long-term treatment with captopril alone attenuates left ventricular remodeling better than its combination with metoprolol. In the head-to-head captopril versus metoprolol therapy strategy comparison, captopril alone seems more effective in reducing postinfarction enlargement, but a definite difference was not demonstrated.


Assuntos
Antagonistas Adrenérgicos beta/uso terapêutico , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Captopril/uso terapêutico , Metoprolol/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Remodelação Ventricular/efeitos dos fármacos , Antagonistas Adrenérgicos beta/farmacologia , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Captopril/farmacologia , Quimioterapia Combinada , Ecocardiografia , Feminino , Humanos , Masculino , Metoprolol/farmacologia , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Estudos Prospectivos , Resultado do Tratamento
8.
J Med Chem ; 43(26): 4934-47, 2000 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-11150164

RESUMO

We have found that certain tetrasubstituted pyrazoles are high-affinity ligands for the estrogen receptor (ER) (Fink et al. Chem. Biol. 1999, 6, 205-219) and that one pyrazole is considerably more potent as an agonist on the ERalpha than on the ERbeta subtype (Sun et al. Endocrinology 1999, 140, 800-804). To investigate what substituent pattern provides optimal ER binding affinity and the greatest enhancement of potency as an ERalpha-selective agonist, we prepared a number of tetrasubstituted pyrazole analogues with defined variations at certain substituent positions. Analysis of their binding affinity pattern shows that a C(4)-propyl substituent is optimal and that a p-hydroxyl group on the N(1)-phenyl group also enhances affinity and selectivity for ERalpha. The best compound in this series, a propylpyrazole triol (PPT, compound 4g), binds to ERalpha with high affinity (ca. 50% that of estradiol), and it has a 410-fold binding affinity preference for ERalpha. It also activates gene transcription only through ERalpha. Thus, this compound represents the first ERalpha-specific agonist. We investigated the molecular basis for the exceptional ERalpha binding affinity and potency selectivity of pyrazole 4g by a further study of structure-affinity relationships in this series and by molecular modeling. These investigations suggest that the pyrazole triols prefer to bind to ERalpha with their C(3)-phenol in the estradiol A-ring binding pocket and that binding selectivity results from differences in the interaction of the pyrazole core and C(4)-propyl group with portions of the receptor where ERalpha has a smaller residue than ERbeta. These ER subtype-specific interactions and the ER subtype-selective ligands that can be derived from them should prove useful in defining those biological activities in estrogen target cells that can be selectively activated through ERalpha.


Assuntos
Fenóis/síntese química , Pirazóis/síntese química , Receptores de Estrogênio/agonistas , Ligação Competitiva , Receptor alfa de Estrogênio , Humanos , Ligantes , Modelos Moleculares , Fenóis/química , Fenóis/metabolismo , Fenóis/farmacologia , Pirazóis/química , Pirazóis/metabolismo , Pirazóis/farmacologia , Ensaio Radioligante , Relação Estrutura-Atividade , Ativação Transcricional , Células Tumorais Cultivadas
9.
Am J Cardiol ; 87(3): 283-8, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11165961

RESUMO

Dobutamine stress echocardiography (DSE) accurately detects viable myocardium and residual ischemia in patients with acute myocardial infarction (AMI). The prognostic interaction of viability and ischemia has not been completely clarified in these patients. This study assesses the long-term effect of viability, ischemia, or their combination on survival in patients with AMI and mildly impaired left ventricular (LV) function. Four hundred eleven patients (age 57 +/- 9 years) underwent predischarge DSE (up to 40 microg/kg/min plus atropine if needed) after uncomplicated AMI and were prospectively followed for 23 months (range 1 to 78). According to DSE findings, patients were divided into 4 groups: viability only, ischemia only, combination of viability and ischemia, and scar. Adverse outcome occurred in 64 patients: 34 patients had hard events (9 cardiac deaths, 25 nonfatal AMI) and 30 patients had unstable angina requiring hospitalization. The combination of viability and ischemia, diabetes mellitus, and non-Q-wave AMI were significant predictors of all events at univariate and multivariate analysis. The same variables were also univariate predictors of hard events, but multivariate analysis indicated only the combination of viability and ischemia and diabetes as independent predictors. The event-free survival of patients with combined viability and ischemia was significantly lower (hazard ratio 3 [95% confidence interval 1.8 to 11]) compared with patients with ischemia only. Thus, viability and ischemia show a significant adverse prognostic interaction in patients with AMI and preserved LV function.


Assuntos
Dobutamina , Teste de Esforço , Infarto do Miocárdio/diagnóstico por imagem , Isquemia Miocárdica/diagnóstico por imagem , Sobrevivência de Tecidos/fisiologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Adulto , Idoso , Angina Instável/diagnóstico por imagem , Angina Instável/fisiopatologia , Morte Súbita Cardíaca/etiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Prognóstico , Estudos Prospectivos , Recidiva , Ultrassonografia , Disfunção Ventricular Esquerda/fisiopatologia
10.
Am J Cardiol ; 84(6): 739-41, A9, 1999 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10498149

RESUMO

The aim of our study was to compare the prognostic value of stress echocardiography and exercise electrocardiography after uncomplicated non-Q-wave acute myocardial infarction in a series of 68 consecutive patients. Our data show that stress echocardiography and exercise electrocardiography offer similar prognostic information after uncomplicated non-Q-wave AMI.


Assuntos
Eletrocardiografia , Teste de Esforço , Infarto do Miocárdio/classificação , Adulto , Idoso , Cardiotônicos , Dipiridamol , Dobutamina , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/mortalidade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Recidiva , Risco , Análise de Sobrevida
11.
Am J Cardiol ; 79(6): 733-7, 1997 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-9070550

RESUMO

We analyzed the relation between dobutamine-induced Q-wave ST-segment elevation and regional contraction during low (5 to 10 microg/kg/min) and high doses (20 to 40 microg/kg/min) of dobutamine in a series of 391 dobutamine echocardiographic tests performed 10 +/- 2 days after a first uncomplicated acute myocardial infarction (AMI). ST-segment elevation was defined as > or = 1 mm new or additional J-point elevation with a horizontal or upsloping ST segment lasting 80 ms. Wall motion score index at rest was derived using a 16 segment-4 grade score model. Patients with dobutamine-induced ST-segment elevation had a higher wall motion score index at rest (anterior wall AMI: 1.67 +/- 0.27 vs 1.43 +/- 0.30, p = 0.0001; inferior wall AMI: 1.44 +/- 0.27 vs 1.30 +/- 0.18, p = 0.0001) and similar incidence and extent of myocardial viability and homozonal ischemia in comparison with those without ST-segment elevation. The sensitivity, specificity, and accuracy of dobutamine-induced ST-segment elevation for detecting residual homozonal ischemia were 51%, 55%, and 54%, respectively, in patients with anterior wall AMI, and 42%, 68%, and 58%, respectively, in patients with inferior wall AMI. In conclusion, dobutamine-induced ST-segment elevation is not associated with higher incidence and extent of viable or jeopardized myocardium but rather to a greater extent of wall motion abnormalities at rest. Thus, this finding does not represent a clinically reliable discriminator for selecting patients for coronary angiography and possible revascularization procedures.


Assuntos
Cardiotônicos , Dobutamina , Eletrocardiografia/efeitos dos fármacos , Infarto do Miocárdio/diagnóstico , Isquemia Miocárdica/diagnóstico , Disfunção Ventricular/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Cardiotônicos/administração & dosagem , Dobutamina/administração & dosagem , Ecocardiografia/efeitos dos fármacos , Ecocardiografia/métodos , Ecocardiografia/estatística & dados numéricos , Eletrocardiografia/métodos , Eletrocardiografia/estatística & dados numéricos , Teste de Esforço/efeitos dos fármacos , Teste de Esforço/métodos , Teste de Esforço/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Sensibilidade e Especificidade
12.
Am J Cardiol ; 81(1): 75-8, 1998 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9462610

RESUMO

Prevalence and prognostic significance of painful and silent ischemia detected by exercise electrocardiography (ECG) and dobutamine stress echocardiography (DSE) were evaluated in 407 consecutive patients recovering from acute myocardial infarction. Painful ischemia assessed by both tests was not associated with different clinical characteristics of patients; on the other hand, it identified a higher risk subgroup compared with silent ischemia during exercise ECG but not during DSE.


Assuntos
Angina Pectoris/etiologia , Cardiotônicos , Dobutamina , Ecocardiografia/normas , Teste de Esforço/normas , Infarto do Miocárdio/complicações , Infarto do Miocárdio/diagnóstico , Idoso , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Reprodutibilidade dos Testes , Fatores de Risco
13.
J Am Soc Echocardiogr ; 12(9): 720-8, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10477416

RESUMO

The aim of this study was to investigate the flow reserve of a normal left anterior descending coronary artery (LAD) in patients with coronary artery disease (CAD) of other epicardial vessels by Doppler transesophageal echocardiography (TEE). Thirty-one consecutive patients (age 59 +/- 8 years; 23 men) referred for TEE were considered. Eighteen patients had CAD and a 70% or greater LAD stenosis (group 1); 13 patients had right and/or circumflex CAD (>/=70% stenosis) and normal or minimally diseased LAD (group 2). Ten patients (age 54 +/- 11 years) with normal coronary arteries constituted group 3. Baseline and adenosine (0.160 microg/kg per minute intravenously over 60 minutes) flow velocities in the LAD were measured by pulsed Doppler examination during TEE. Peak and mean systolic and diastolic flow velocities were calculated. Adenosine/baseline peak and mean velocity ratios were used for evaluating blood flow reserve in the LAD. Heart rate and arterial pressure values were similar in the 3 groups at baseline and during adenosine infusion. Baseline and adenosine-related flow velocities were comparable in the 3 groups. Peak and mean diastolic velocity ratios were lower in groups 1 and 2 compared with group 3 (peak velocity ratio 1.68 +/- 0.81 and 1.93 +/- 0.35 vs 2.62 +/- 0.32, P <. 05; mean velocity ratio 1.71 +/- 0.86 and 2.01 +/- 0.41 vs 2.84 +/- 0.74, P <.05), whereas no differences were found between groups 1 and 2. No significant differences were found in systolic flow velocity ratios among the 3 groups. Patients with ischemic heart disease have a reduced diastolic flow velocity reserve in the LAD independent from the presence of significant LAD stenosis. Thus the adenosine TEE-Doppler study should be considered a screening test for CAD rather than for LAD disease.


Assuntos
Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Ecocardiografia Doppler , Ecocardiografia Transesofagiana , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/fisiopatologia , Idoso , Velocidade do Fluxo Sanguíneo , Angiografia Coronária , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional , Sensibilidade e Especificidade
14.
Int J Cardiol ; 24(3): 283-8, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2767807

RESUMO

Tremors of the isoelectric line in routine electrocardiograms have been described in patients with spinal muscular atrophy and have been interpreted as fasciculations of denervated muscles. In order to evaluate this phenomenon, 13 patients with spinal muscular atrophy have been studied (average age: 37.3 months). A first electrocardiogram was recorded routinely; a second tracing was then recorded with double sensitivity and double speed. In addition, all patients were evaluated clinically and had M-mode and cross-sectional echocardiography. Regular and constant spikes on the isoelectric electrocardiographic line were recorded in 12 patients (93.4%); their frequency ranged from 39 to 48 cycles/sec (average: 42.08 +/- 2.64). Contrary to previous reports, we found an "abnormal" electrocardiogram in all our patients with severe spinal muscular atrophy. The only patient with a normal electrocardiogram had a mild and clinically stable form of spinal muscular atrophy. We did not find any significant structural cardiac abnormality by clinical and echocardiographic evaluation. We conclude that continuous tremor on the isoelectric line of electrocardiogram represents a characteristic of spinal muscular atrophy in these patients. It is a result of muscle fasciculations and does not imply any abnormality of the heart.


Assuntos
Eletrocardiografia , Fasciculação/diagnóstico , Atrofia Muscular Espinal/complicações , Adolescente , Criança , Pré-Escolar , Diagnóstico Diferencial , Ecocardiografia , Fasciculação/etiologia , Fasciculação/fisiopatologia , Feminino , Cardiopatias/diagnóstico , Humanos , Lactente , Masculino , Atrofia Muscular Espinal/patologia , Atrofia Muscular Espinal/fisiopatologia , Atrofias Musculares Espinais da Infância/complicações , Atrofias Musculares Espinais da Infância/patologia , Atrofias Musculares Espinais da Infância/fisiopatologia
15.
Ital Heart J Suppl ; 1(2): 241-9, 2000 Feb.
Artigo em Italiano | MEDLINE | ID: mdl-10731382

RESUMO

BACKGROUND: The aim of this study was to verify the changes in the autonomic balance by means of heart rate variability assessment in patients with myocardial infarction referred for cardiac rehabilitation. METHODS: We studied 122 patients (79 males, 43 females, mean age 56 +/- 5 years), with a first uncomplicated myocardial infarction (anterior 48, thrombolysis 72), Killip class 1, preserved left ventricular function (ejection fraction 49 +/- 6%). All patients were free of inducible residual ischemia. Four weeks after myocardial infarction, patients were randomized into two groups; Group 1 (n = 58) referred for an 8 week cardiac rehabilitation program (scheduled: 24 sessions); Group 2 (n = 64): normal daily physical activity. During a 24-hour Holter ECG monitoring the following parameters were calculated in pharmacological wash-out at randomization (T0) and at the end of cardiac rehabilitation/control period (T1): mean value of RR intervals (RR), its standard deviation (SDNN), pNN50, rMSSD in the time domain; low frequency (LF) and high frequency (HF) value and the LF/HF ratio in the frequency domain. T1-T0 changes in percent values (delta %) were considered and compared between the two groups. RESULTS: Thirty-one patients were excluded from the study either for insufficient adhesion to the cardiac rehabilitation program (< 13 sessions, 22 patients) or recurrent ischemia (3 Group 1 patients and 3 Group 2 patients) and non-assessable 24-hour Holter ECG monitoring (3 patients). Thirty-one Group 1 patients and 60 Group 2 patients completed the study with a first and a second 24-hour Holter ECG monitoring performed at 30 +/- 3 days and 60 +/- 4 days respectively. At the same time an ergospirometric test was performed to evaluate cardiopulmonary function by means of exercise time, maximum oxygen consumption, anaerobic threshold, exercise time at the anaerobic threshold, and maximum oxygen consumption at the anaerobic threshold. Twenty-eight Group 1 patients and 44 Group 2 patients completed the study with a first and a second ergospirometric test. Baseline heart rate variability parameters were comparable in the two groups. During the observation period only in Group 1 patients heart rate variability parameters changed significantly: RR (Group 1 = +18.3 +/- 21.3; Group 2 = +4.2 +/- 5.2, p = 0.000), pNN50 (Group 1 = 45.0 +/- 38.9; Group 2 = +24.2 +/- 34.7, p = 0.011), HF (Group 1 = +81.6 +/- 124; Group 2 = -28.7 +/- 75.4, p = 0.014) and LF/HF ratio (Group 1 = -26.0 +/- 16.1; Group 2 = -4.9 +/- 6.1, p = 0.062). There were no significant differences in SDNN, rMSSD and LF. A linear correlation between delta LF/HF ratio and baseline LF/HF ratio values was found in Group 1 (r = 0.489, p = 0.006), whereas no correlation was found between this parameter and age, ejection fraction, creatine phosphokinase, and infarct localization. Group 1 patients had a significant improvement in exercise tolerance compared to Group 2 patients. CONCLUSIONS: A cardiac rehabilitation program positively modifies the sympatho-vagal balance in patients with uncomplicated myocardial infarction, increasing the parasympathetic tone and exercise tolerance.


Assuntos
Frequência Cardíaca/fisiologia , Infarto do Miocárdio/fisiopatologia , Infarto do Miocárdio/reabilitação , Idoso , Distribuição de Qui-Quadrado , Terapia Combinada , Eletrocardiografia Ambulatorial/métodos , Eletrocardiografia Ambulatorial/estatística & dados numéricos , Teste de Esforço/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
17.
J Matern Fetal Neonatal Med ; 25 Suppl 4: 139-40, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22958046

RESUMO

Over the last decade, the survival of premature babies has improved dramatically. Such infants, especially those with extremely low birth weight, are still affected by dangerous complications occurring during the neonatal period that often cause brain damage. Intraventricular-intraparenchymal haemorrhage (IVH-IPH), periventricular leukomalacia (PVL), seizures, meningitis and hypoxic-ischaemic encephalopathy are the most common complications. Such problems require more specialized monitoring of brain function during this critical period. In recent years, many studies on very premature infants have shown that aEEG has a high predictive value for both short-term and long-term outcome. In fact, it has been proven that some types of background activity patterns, the absence of a sleep-wake cycle, and seizure activity are related to the onset of early complications such as IVH-IPH and PVL. Most recent studies have shown that an aEEG performed in the early hours or during the first days of life can predict the neurobehavioural development of preterm infants at 2 years and 3 years (Bayley Scale). In particular our study demonstrates that loss of sleep-wake cycling, shown by aEEG, has a high positive predictive value for the development of posthaemorrhagic hydrocephalus (PPH) in preterm infants with IVH; therefore, the study of cerebral background activity and in particular of sleep-wake cycling can be used as an early prognostic tool in patients at risk of PPH.


Assuntos
Eletroencefalografia/métodos , Hidrocefalia/diagnóstico , Doenças do Prematuro/diagnóstico , Recém-Nascido Prematuro/fisiologia , Transtornos do Sono do Ritmo Circadiano/diagnóstico , Hemorragia Cerebral , Diagnóstico Precoce , Humanos , Hidrocefalia/congênito , Hidrocefalia/etiologia , Hipóxia-Isquemia Encefálica/complicações , Hipóxia-Isquemia Encefálica/diagnóstico , Recém-Nascido , Doenças do Prematuro/fisiopatologia , Projetos Piloto , Valor Preditivo dos Testes , Transtornos do Sono do Ritmo Circadiano/complicações , Transtornos do Sono do Ritmo Circadiano/congênito
18.
Br J Pharmacol ; 165(6): 1891-1903, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21943108

RESUMO

BACKGROUND AND PURPOSE: Pathological angiogenesis is associated with various human diseases, such as cancer, autoimmune diseases and retinopathy. The angiopoietin (Ang)-Tie2 system plays critical roles in several steps of angiogenic remodelling. Here, we have investigated the anti-angiogenic effect of a novel angiopoietin-derived peptide. EXPERIMENTAL APPROACH: Using computational methods, we identified peptides from helical segments within angiopoietins, which were predicted to inhibit their activity. These peptides were tested using biochemical methods and models of angiogenesis. The peptide with best efficacy, A11, was selected for further characterization as an anti-angiogenic compound. KEY RESULTS: The potent anti-angiogenic activity of A11 was demonstrated in a multicellular assay of angiogenesis and in the chorioallantoic membrane model. A11 bound to angiopoietins and reduced the binding of Ang-2 to Tie2. A11 was also significantly reduced vascular density in a model of tumour-induced angiogenesis. Its ability to inhibit Ang-2 but not Ang-1-induced endothelial cell migration, and to down-regulate Tie2 levels in tumour microvessels, suggests that A11 targets the Ang-Tie2 pathway. In a rat model of oxygen-induced retinopathy, A11 strongly inhibited retinal angiogenesis. Moreover, combination of A11 with an anti-VEGF antibody showed a trend for further inhibition of angiogenesis, suggesting an additive effect. CONCLUSIONS AND IMPLICATIONS: Our results indicate that A11 is a potent anti-angiogenic compound, through modulation of the Ang-Tie2 system, underlining its potential as a therapeutic agent for the treatment of ocular and tumour neovascularization, as well as other pathological conditions that are dependent on angiogenesis.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Peptídeos/uso terapêutico , Neovascularização Retiniana/tratamento farmacológico , Inibidores da Angiogênese/farmacologia , Angiopoietinas/metabolismo , Animais , Movimento Celular/efeitos dos fármacos , Galinhas , Membrana Corioalantoide/irrigação sanguínea , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Feminino , Células HCT116 , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/fisiologia , Humanos , Camundongos , Camundongos Nus , Neovascularização Patológica/patologia , Peptídeos/farmacologia , Ratos , Ratos Sprague-Dawley , Neovascularização Retiniana/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
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