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1.
Clin Radiol ; 75(5): 383-389, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32111403

RESUMO

AIM: To evaluated T1-, T2 mapping, and a three-dimensional (3D) T2-weighted fast-spin-echo triple inversion recovery sequences (3D STIR) for diagnosing myocardial oedema in patients with suspected early myocarditis and at follow-up. MATERIALS AND METHODS: Sixteen patients with suspected myocarditis and 15 controls matched for gender and age were examined prospectively. To evaluate oedema, an electrocardiogram-triggered T1 and T2 mapping with a gradient spin echo technique and 3D STIR sequences were used to cover the entire left ventricle. The signal intensity ratio (heart muscle in relation to skeletal muscle) was calculated (3D STIR ratio). All patients underwent repeat examinations at follow-up. RESULTS: The mean 3D-STIR ratio was 2.14±0.45 at the patients' initial examination as compared to the control patients' 1.54±0.18 in (p=0.0001) and 1.75±0.16 in patients at follow-up (p=0.002 versus first visit). The 3D STIR ratio of the septum, anterior, lateral, and inferior wall also differed significantly between patients and controls. No significant difference was observed in T1 and T2 mapping between patients and controls at baseline and patients at follow-up. CONCLUSIONS: A significantly higher global signal intensity ratio with 3D-STIR was identified in patients with suspected myocarditis compared to controls, and a significant change during follow-up. No significant difference was detected in T1-, T2 mapping between patients and controls, or between the initial examination and follow-up of patients. The global 3D-STIR ratio may therefore be useful for the diagnosis of myocarditis and should be explored further.


Assuntos
Edema/diagnóstico por imagem , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Miocardite/diagnóstico por imagem , Estudos de Casos e Controles , Meios de Contraste , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Masculino , Meglumina , Pessoa de Meia-Idade , Compostos Organometálicos , Pacientes Ambulatoriais , Estudos Prospectivos
2.
Clin Radiol ; 73(2): 219.e9-219.e15, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29054563

RESUMO

AIM: To evaluate early diastolic septal relaxation as a parameter in the diagnostic workup via cardiovascular magnetic resonance imaging (CMRI) in patients with myocarditis. MATERIALS AND METHODS: Early diastolic septal movement was evaluated (EDS) prospectively via frame-by-frame analysis in 255 consecutive patients with presenting signs of myocarditis and in 64 controls matched 4:1 for gender and age. ECG-triggered, T2-weighted, fast spin echo triple inversion recovery sequences and late gadolinium enhancement were obtained, as well as left ventricular (LV) function and dimensions in patients and controls. RESULTS: EDS was detected in 66.7% of the patients and 18.7% of the controls (p<0.001). Sensitivity was 69.4% and specificity 79.7%. Patients with EDS had a significant lower LV ejection fraction (LV-EF) of 61.1±0.6% and significant higher end-diastolic volume (EDV) of 158.5±2.7 ml than in patients without EDS (LV-EF 65.3±0.9%, p=0.0001; EDV 148.4±3.9 ml, p=0.04). A significant negative correlation was observed between LV-EF and EDS in patients, and a lower LV-EF correlated with a more frequent occurrence of EDS (r=-0.24, p=0.0001). Scar tissue was also more frequent in patients than controls (63.1% and 7.8%, p=0.007). CONCLUSIONS: EDS is a parameter obtained non-invasively by CMRI and is present in a high percentage of patients with myocarditis. Cardiac functional parameters are significantly altered in patients with EDS. EDS is a feasible parameter that can play an important role in the diagnosis of myocarditis.


Assuntos
Diástole/fisiologia , Septos Cardíacos/diagnóstico por imagem , Septos Cardíacos/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Miocardite/diagnóstico por imagem , Miocardite/fisiopatologia , Meios de Contraste , Feminino , Gadolínio , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Aumento da Imagem/métodos , Masculino , Pessoa de Meia-Idade , Miocardite/complicações , Estudos Prospectivos , Sensibilidade e Especificidade , Disfunção Ventricular Esquerda/complicações , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/fisiopatologia
3.
Acta Physiol Hung ; 100(1): 1-27, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23471039

RESUMO

In our previous review characteristics of the athlete's heart were divided into three groups: morphologic (left ventricular (LV) hypertrophy, improved coronary circulation), functional (better diastolic function) and regulatory (lower heart rate (HR)) features. In the present review, the influences of the types of sports and the age on the athlete's heart are discussed. Studies using echocardiographic, Doppler-echocardiographic, tissue Doppler imaging (TDI) and magnetic resonance imaging (MRI) results are mostly involved. The coronary circulation was investigated overwhelmingly in animal experiments. In the LV hypertrophy a major contributor is the increase of the LV wall thickness (WT) than that of the LV internal diameter (ID). A right ventricular (RV) hypertrophy can also be seen in athletes. Athletic features are induced mostly by endurance training. Approximately two years regular physical training is needed to develop characteristics of the athlete's heart, hence, in the young children they are less marked. LV hypertrophy and lower HR are characteristic in young and adult athletes, but they are less marked in older ones. A richer coronary capillary network can develop mostly at a young age.


Assuntos
Atletas , Cardiomegalia Induzida por Exercícios/fisiologia , Coração/fisiologia , Esportes/fisiologia , Fatores Etários , Animais , Humanos , Resistência Física/fisiologia
4.
Acta Physiol Hung ; 97(4): 337-53, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21138810

RESUMO

Importance of the athlete's heart has been arisen in the last decades.

    Consequences of the sedentary way of life are the most threatening through the impairments of the cardiovascular system. Endurance performance is mostly limited by the characteristics of the athlete's heart. Sudden death of the athletes is always associated with cardiac disorders.
Main characteristics of the athlete's heart can be divided into morphologic, functional and regulatory ones.
    The main morphologic characteristics are the physiologic left ventricular (LV) hypertrophy and a richer coronary capillary network. The functional adaptation contains a better systolic and diastolic function, modified metabolism and electric characteristics. The most easily detected modification is the better LV diastolic function. Adaptation of the cardiac regulation is manifested mostly by a lower heart rate (HR).
Summarizing: the athlete's heart is an enlarged but otherwise normal heart characterized by a low heart rate, an increased pumping capacity, and a greater ability to deliver oxygen to skeletal muscle.


Assuntos
Atletas , Exercício Físico , Coração/fisiopatologia , Hipertrofia Ventricular Esquerda/etiologia , Função Ventricular Esquerda , Adaptação Fisiológica , Sistema Nervoso Autônomo/fisiopatologia , Circulação Coronária , Morte Súbita Cardíaca/etiologia , Morte Súbita Cardíaca/prevenção & controle , Metabolismo Energético , Coração/inervação , Frequência Cardíaca , Humanos , Hipertrofia Ventricular Esquerda/fisiopatologia , Microcirculação , Contração Miocárdica
5.
Z Kardiol ; 90(6): 385-93, 2001 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-11486572

RESUMO

There are currently no randomized and carefully controlled human trials to definitively prove that endocarditis prophylaxis is efficient. Furthermore, most cases of endocarditis are not attributable to a medical procedure. Thus, even with a high level of application of endocarditis prophylaxis only a minority of cases could be prevented. Endocarditis is a rare disease. On the other hand, its morbidity is increasing! In addition, infective endocarditis remains still a major medical concern because of its mortality between 5% and 76%. In addition, in up to 40% of all patients suffering from endocarditis one or more heart valves have to be replaced in the following 5 to 8 years. Without treatment endocarditis has a lethality of 100%. Therefore, there is worldwide agreement that endocarditis prophylaxis is necessary. Combining the recommendations of the German and the American Heart Association, as well as the results of the European consensus conferences, with newer insights into the pathophysiology of endocarditis the following aspects are elucidated: depending on their risk of endocarditis patients are allocated into 3 groups. In the first group there are patients with prosthetic cardiac valves, patients who suffered from previous endocarditis and patients with complex cyanotic congenital heart disease and surgically constructed shunts or conduits of the aorta and/or pulmonary circulation. In these high-risk patients the prophylactic regimen for dental, oral, respiratory tract procedures is oral amoxycillin. In genitourinary and gastrointestinal procedures ampicillin and gentamicin i.v. is recommended. In patients with mostly congenital cardiac malformations, acquired valvular dysfunction, hypertrophic obstructive cardiomyopathy and mitral valve prolapse or thickened leaflets and valvular regurgitation oral amoxycillin is recommended for all medical procedures (second group). The third group consists of patients with isolated secundum atrial defect, previous coronary bypass graft surgery, patients with cardiac pacemakers or defibrillators. In this patient cohort the individual risk of endocarditis is not higher than in the general population. Therefore, endocardits prophylaxis is not recommended.


Assuntos
Antibioticoprofilaxia , Endocardite Bacteriana/prevenção & controle , Ensaios Clínicos como Assunto , Endocardite Bacteriana/etiologia , Alemanha , Humanos , Guias de Prática Clínica como Assunto , Fatores de Risco
6.
Int J Card Imaging ; 16(1): 1-12, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10832619

RESUMO

In patients with coronary artery disease coronary angiography plays an important role in the clinical decision-making process. However, it has been recognized that no simple relation exists between the visually or quantitatively evaluated severity of coronary artery stenoses and its effects on regional myocardial perfusion. This paper describes for the first time the development and application of a 3D technique that visualizes and quantifies regional myocardial perfusion parameters from biplane coronary angiograms by using the impulse response analysis technique. The 3D reconstructed coronary tree is automatically superimposed on the 3D perfusion image to generate and visualize an 'integrated' 3D image. The preliminary results in patients with critical coronary artery stenoses indicate that our combined 3D fusion image provides flow information from the major coronary arteries. This 3D fusion image may provide useful information in the management of patients with coronary artery disease.


Assuntos
Angiografia Digital/métodos , Angioplastia Coronária com Balão , Angiografia Coronária/métodos , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/terapia , Idoso , Circulação Coronária , Vasos Coronários , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Intensificação de Imagem Radiográfica/métodos , Sensibilidade e Especificidade
7.
Z Kardiol ; 89(4): 338-48, 2000 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-10868009

RESUMO

The interpretation of three-dimensional (3D) structures of the coronary tree and the myocardium by a clinician demands a subjective visual integration of two-dimensional (2D) images of cardiac diagnostic procedures like coronary angiography and myocardial scintigraphy. Although in the conventional analysis of 2D display scintigraphic myocardial perfusion segments are arbitrarily assigned to three major coronary artery systems, the standard myocardial perfusion distribution territories correspond with the individual pathologic-anatomic coronary tree in only 50-60% of the patients. Hence, the mental integration of both 2D images of coronary angiography and myocardial scintigraphy does not necessarily allow an accurate assignment of particular myocardial perfusion regions to the corresponding vessels. For an objective assignment of each vessel segment of the coronary tree to the corresponding myocardial regions, we have developed a 3D "fusion image" technique and applied it to patients with coronary artery disease. Cause-and-effect relationships may be more obvious with 3D data fusion and may enable an easier comparison of anatomy and physiology. Preliminary results demonstrate that our newly developed 3D fusion image is useful for accurate assignment of coronary vessel segments to the corresponding myocardial perfusion regions and suggest that it may allow the clinician a comprehensive and accurate assessment of the patient's myocardial status.


Assuntos
Angiografia Coronária , Doença das Coronárias/diagnóstico , Processamento de Imagem Assistida por Computador , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada de Emissão , Circulação Coronária/fisiologia , Doença das Coronárias/fisiopatologia , Teste de Esforço , Humanos , Fluxo Sanguíneo Regional/fisiologia
8.
Herz ; 25(7): 689-93, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11141678

RESUMO

This report presents a 46-year-old man who was treated for hypertension with the angiotensin-converting-enzyme (ACE) inhibitor enalapril. After 3 years of continuous treatment he presented with jaundice and progressive liver failure that continued despite withdrawal of the medication. The patient was taking no other medication. All known causes of acute liver failure could be excluded indicating a drug-induced liver damage after long-term treatment with enalapril. Analysis of liver biopsies revealed a pathomorphological pattern comparable to than observed in severe halothane hepatitis. Serological studies including T-cell stimulation with enalapril and a broad spectrum of tests for autoimmunity including autoantibodies against calreticulin, the major Ca2+ and Zn2+ binding protein of the endoplasmic reticulum and suggested to be involved in the pathogenesis of halothane hepatitis were negative. Thus, the mechanism of enalapril-induced liver injury remains obscure. Liver failure progressed and finally led to orthotopic liver transplantation. To our knowledge, this is the longest duration of chronic treatment with an ACE inhibitor before liver failure occurred. In addition, liver failure progressed despite withdrawal of the medication. It is concluded that even after long-term treatment with an ACE inhibitor liver failure may be induced. Therefore, regular monitoring of liver enzymes should be considered.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Enalapril/efeitos adversos , Hipertensão/tratamento farmacológico , Falência Hepática Aguda/induzido quimicamente , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Biópsia , Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Induzida por Substâncias e Drogas/patologia , Progressão da Doença , Enalapril/uso terapêutico , Seguimentos , Humanos , Hipertensão/patologia , Fígado/patologia , Falência Hepática Aguda/diagnóstico , Falência Hepática Aguda/patologia , Masculino , Pessoa de Meia-Idade
9.
Cardiology ; 94(4): 239-46, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11326145

RESUMO

BACKGROUND: In chronic smokers there is evidence for increased formation of oxygen-derived free radicals within the vessel wall impairing endothelial function. It has been suggested that the inactivation of endothelium-derived nitric oxide by oxygen free radicals contributes to endothelial dysfunction. Hence, we tested the hypothesis that in chronic smokers the antioxidant ascorbic acid could improve abnormal endothelial function of epicardial coronary arteries. METHODS AND RESULTS: Thirty-one patients (mean age 57 +/- 9 years) referred for routine diagnostic catheterization for evaluation of chest pain and without angiographically significant coronary artery stenoses were randomly assigned to one of the study groups to assess vasomotor response of epicardial coronary arteries due to cold pressor testing (CPT) before and after intravenous infusion of 3 g of ascorbic acid or 100 ml x 0.9% saline infusion. In 6 controls (mean age 55 +/- 3 years) CPT led to a similar increase in luminal area before and after ascorbic acid administration (26.5 +/- 15.0 vs. 28.4 +/- 17.7%, p = NS). In 15 chronic smokers (mean age 55 +/- 9 years), CPT induced a decrease in the luminal area of -18.5 +/- 6.3%. This flow-dependent vasoconstriction was significantly reversed to 7.7 +/- 6.2% (p < or = 0.03) vasodilation after intravenous ascorbic acid administration. In 10 chronic smokers (mean age 57 +/- 11 years) saline infusion (placebo) did not have a significant effect on CPT-induced vasoconstriction (-12.7 +/- 5.1 vs. -13.1 +/- 5.1%, p = NS). The CPT-induced increase in luminal area in chronic smokers after ascorbic acid infusion was significant compared to controls and placebo (each p < or = 0.05). Our assessment of endothelium-independent responses to nitroglycerin revealed no significant differences between the single study groups (p = NS). CONCLUSION: In chronic smokers acute intravenous administration of ascorbic acid significantly improves CPT-induced coronary endothelium-dependent dysfunction. According to the current understanding, this effect is due to improved cellular redox imbalance and prevention of nitric oxide inactivation in the endothelium and subendothelial space.


Assuntos
Antioxidantes/farmacologia , Pressão Sanguínea/fisiologia , Temperatura Baixa , Vasos Coronários/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Fumar/efeitos adversos , Idoso , Ácido Ascórbico/análise , Ácido Ascórbico/farmacologia , Colesterol/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitroglicerina/farmacologia , Estudos Prospectivos , Vasoconstrição/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia
10.
Int J Card Imaging ; 15(5): 357-68; discussion 369-70, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10595402

RESUMO

BACKGROUND: In patients with coronary artery disease, coronary angiography is performed for assessment of epicardial coronary artery stenoses. In addition, myocardial scintigraphy is commonly used to evaluate regional myocardial perfusion. These two-dimensional (2D) imaging modalities are typically reviewed through a subjective, visual observation by a physician. Even though on the analysis of 2D display scintigraphic myocardial perfusion segments are arbitrarily assigned to three major coronary artery systems, the standard myocardial distribution territories of the coronary tree correspond only in 50-60% of patients. On the other hand, the mental integration of both 2D images of coronary angiography and myocardial scintigraphy does not allow an accurate assignment of particular myocardial perfusion regions to the corresponding vessels. To achieve an objective assignment of each vessel segment of the coronary artery tree to the corresponding myocardial regions, we have developed a 3D 'fusion image' technique and applied it to patients with coronary artery disease. The morphological data (coronary angiography) and perfusion data (myocardial scintigraphy) are displayed in a 3D format, and these two 3D data sets are merged into one 3D image. RESULTS: Seventy-eight patients with coronary artery disease were studied with this new 3D fusion technique. Of 162 significant coronary lesions, 120 (74%) showed good coincidence with regional myocardial perfusion abnormality on 3D fusion image. No regional myocardial perfusion abnormality was found in 44 (26%) lesions. Furthermore, the 3D fusion image revealed 24 ischemic myocardial regions that could not be related to angiographically significant coronary artery lesions. CONCLUSION: The results of this study demonstrate that our newly developed 3D fusion technique is useful for an accurate assignment of coronary vessel segments to the corresponding myocardial perfusion regions, and suggest that it may be helpful to improve the interpretative and decision-making process in the treatment of patients with coronary artery disease.


Assuntos
Angiografia Coronária/métodos , Doença das Coronárias/diagnóstico , Coração/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Idoso , Doença das Coronárias/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/diagnóstico , Fluxo Sanguíneo Regional , Tomografia Computadorizada de Emissão , Tomografia Computadorizada de Emissão de Fóton Único
11.
Eur Heart J ; 20(22): 1676-80, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10543931

RESUMO

AIMS: There is evidence that formation of free radicals increases in patients with hypertension or hypercholesterolaemia, which may contribute to endothelial dysfunction of epicardial coronary arteries due to inactivation of the vasodilator NO. The present study was designed to test whether the abnormal constriction of epicardial coronary arteries due to sympathetic stimulation by the cold pressor test in patients with essential hypertension or hypercholesterolaemia could be reversed by administration of the antioxidant vitamin C. METHODS AND RESULTS: In 28 patients without relevant coronary artery stenosis the cold pressor test was performed before and after a 3 g infusion of vitamin C. In five normal controls the cold pressor test led to a similar increase in luminal area before and after vitamin C (3.7+/-1.3% and 1.9+/-0.8%, ns vs before vitamin C). In nine hypercholesterolaemic patients the cold pressor test led to a -14.1+/-2.8% reduction in cross-sectional area before vitamin C. This constriction was significantly improved after vitamin C to -7.6%+/-2.0, P=0.027 vs before vitamin C. In nine hypertensive patients, the cold pressor test led to a -17.1+/-3.2% decrease in cross-sectional area before vitamin C, which was improved to -7.1+/-3.1 after vitamin C, P=0.004 vs before vitamin C. This increase in luminal area was significant in each group in comparison with normal controls (each P<0.05). Administration of saline (placebo group, five patients) had no significant effect on cold pressor test-induced constriction (-6.9+/-3.9% before and -6. 8+/-3.7% after saline). CONCLUSION: The antioxidant vitamin C reverses cold pressor test-induced vasoconstriction of epicardial coronary arteries in patients with hypertension or hypercholesterolaemia. Our data suggest that enhanced oxidative stress contributes to impaired endothelial function in this patient population.


Assuntos
Ácido Ascórbico/administração & dosagem , Vasos Coronários/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Hipercolesterolemia/tratamento farmacológico , Hipertensão/tratamento farmacológico , Idoso , Ácido Ascórbico/fisiologia , Temperatura Baixa , Vasos Coronários/fisiologia , Endotélio Vascular/fisiologia , Feminino , Humanos , Hipercolesterolemia/fisiopatologia , Hipertensão/fisiopatologia , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Estresse Oxidativo/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos , Resistência Vascular/fisiologia
12.
Z Kardiol ; 87(2): 77-83, 1998 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-9556869

RESUMO

Nitrates act, in part, by causing systemic venodilation. In addition, nitrates lead to dilation of arterial conductance vessels. The maximal dilation capacity and threshold of arterial conductance vessels have so far not been examined thoroughly. Therefore, we tested the radial artery diameter before and after i.v. nitroglycerin infusions at increasing dosages (0.015, 0.05, 0.15, 0.5, and 1.5 micrograms/kg/min), 7 min each dose in 28 patients with suspected coronary artery disease (mean age +/- SEM 58 +/- 2 years) using a high resolution ultrasound devise. The low doses of 0.05 and 0.15 microgram/kg/min, equal to dose of 2.5 mg/12 hours and 7.5 mg/12 hours in a patient with 70 kg, led to substantial increases in the cross sectional luminal area of the radial artery of 14.8 +/- 1.5% and 29.3 +/- 2.2%*, (*p < 0.05 vs baseline). The maximal increase (dilatory capacity) was 53.8 +/- 3.8% (mean diameter at baseline: 2.7 +/- 0.1 mm, maximal 3.4 +/- 0.1 mm, p < 0.001). The nitrate sensitivity of the radial artery was estimated by calculation of the ED50, the dose that caused half-maximal dilation of the radial artery. The ED50 of the radial artery was 0.13 +/- 0.003 microgram/kg/min. In conclusion, nitroglycerin leads to a dose dependent dilatation of peripheral conductance vessels. Low doses of 0.05 and 0.15 microgram/kg/min lead to significant arterial dilation. The maximal dilatory capacity of the radial artery is 53.8 +/- 3.5%.


Assuntos
Músculo Liso Vascular/efeitos dos fármacos , Nitroglicerina/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Administração Sublingual , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/fisiopatologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Músculo Liso Vascular/fisiopatologia , Artéria Radial/diagnóstico por imagem , Artéria Radial/efeitos dos fármacos , Artéria Radial/fisiopatologia , Transdutores , Ultrassonografia/instrumentação , Vasodilatação/fisiologia
13.
Circulation ; 96(5): 1513-9, 1997 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-9315540

RESUMO

BACKGROUND: There is evidence for increased formation of free radicals in patients with hypertension, raising the possibility that NO is inactivated by free radicals, which impairs coronary endothelial function. Therefore, we tested the hypothesis that the antioxidant vitamin C could improve abnormal endothelial function of coronary arteries in patients with hypertension. METHODS AND RESULTS: In 22 hypertensive patients without relevant coronary artery stenoses, endothelium-dependent vascular responses of the left anterior descending coronary artery (LAD) to acetylcholine (0.01, 0.1, and 1.0 micromol/L) were determined before and immediately after intravenous infusion of 3 g vitamin C (17 patients) or placebo (5 patients). In a subgroup of 10 patients, papaverine-induced flow-dependent vasodilation (FDD) was measured before and after vitamin C (5 patients) or placebo (5 patients) infusion. Segmental responses of the coronary artery luminal area were analyzed with quantitative coronary angiography. Before vitamin C infusion, the mean changes of LAD luminal areas at increasing doses of acetylcholine were -6.1+/-2.2%, -15.2+/-4.9%, and -33.9+/-8.1% (negative numbers symbolize vasoconstriction) and during FDD, 5.4+/-1.0%. The vasoconstrictor response during acetylcholine was reduced and FDD was augmented by vitamin C. After vitamin C infusion, LAD luminal areas changed by -3.2+/-2.3%, -5.8+/-3.6%, and -10.2+/-5.6% (P<.05, acetylcholine) and 17.8+/-2.8% (P<.05, FDD). Doppler flow velocity (during baseline, acetylcholine, and FDD) was not significantly affected by vitamin C. CONCLUSIONS: Vitamin C improves the endothelium-dependent vasomotor capacity of coronary arteries in patients with hypertension and patent coronary arteries. These findings suggest that increased oxidative stress contributes to endothelial dysfunction in hypertensive patients.


Assuntos
Antioxidantes/uso terapêutico , Ácido Ascórbico/uso terapêutico , Vasos Coronários/efeitos dos fármacos , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/fisiopatologia , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Acetilcolina/uso terapêutico , Adulto , Idoso , Artérias/efeitos dos fármacos , Artérias/fisiopatologia , Vasos Coronários/fisiopatologia , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Papaverina/uso terapêutico , Pericárdio , Vasodilatadores/uso terapêutico
15.
Am J Cardiol ; 76(14): 1079-82, 1995 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-7484869

RESUMO

The present study demonstrates that peripheral vasodilatory capacity is impaired in patients with chronic congestive heart failure not treated with aspirin, but preserved in patients taking aspirin. This decreased peripheral vasodilatory capacity can be restored by chronic angiotensin-converting enzyme inhibition, indicating that locally acting cyclooxygenase-dependent factors contribute to peripheral vasoconstriction in chronic congestive heart failure.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Indóis/uso terapêutico , Resistência Vascular/efeitos dos fármacos , Vasodilatação/efeitos dos fármacos , Adulto , Idoso , Doença Crônica , Feminino , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Perindopril , Artéria Radial/efeitos dos fármacos , Artéria Radial/fisiopatologia
16.
Am J Cardiol ; 76(15): 13E-18E, 1995 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-7484881

RESUMO

Chronic heart failure is associated with neurohumoral activation and alterations of the peripheral circulation and skeletal muscle. Several mechanisms are involved in the impaired peripheral perfusion, including increased sympathetic tone and increased vascular stiffness. Recently, data suggest an important role of the endothelium for perfusion of skeletal muscle in heart failure. Endothelium-dependent dilation of resistance vessels is blunted in patients with severe chronic heart failure and may be involved in the impaired reactive hyperemia in these patients. In conductance vessels, flow-dependent dilation and the nitroglycerin-induced dilator response is attenuated in congestive heart failure as compared to normal subjects, indicating both endothelial dysfunction and a defect of smooth muscle relaxation. Recent data suggest that angiotensin-converting enzyme (ACE) inhibitors can improve endothelial function of resistance vessels, reduce serum level of the soluble endothelial (vascular cell) adhesion molecule (VCAM-1) and, in addition, improve peripheral vascular function by reducing or limiting the influence of cyclo-oxygenase-dependent vasoconstricting factor(s). It is conceivable that these beneficial effects of chronic ACE inhibition are due, in part, to blockade of bradykinin degradation by the ACE and the increased endothelial synthesis of prostaglandins and/or the release of nitric oxide by enhanced tissue levels of bradykinin.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Endotélio Vascular/efeitos dos fármacos , Insuficiência Cardíaca/tratamento farmacológico , Idoso , Doença Crônica , Endotélio Vascular/metabolismo , Endotélio Vascular/fisiopatologia , Feminino , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Prostaglandinas/metabolismo , Molécula 1 de Adesão de Célula Vascular/metabolismo
17.
J Am Coll Cardiol ; 26(1): 50-6, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7797775

RESUMO

OBJECTIVES: We examined whether reflex neurohormonal constrictor forces attenuate the vasodilator action of nitroglycerin on large peripheral conductance vessels. BACKGROUND: Continuous nitroglycerin therapy is associated with the development of early tolerance with respect to its hemodynamic effects. It remains to be demonstrated whether vascular tolerance of large conductance vessels is an important contributory factor. METHODS: Radial artery diameter and forearm blood flow velocity were measured before and 24 and 48 h after continuous intravenous nitroglycerin infusion (0.5 microgram/kg body weight per min) in 10 patients with coronary artery disease (mean age +/- SEM 59 +/- 4 years) by using a high resolution ultrasound device. Blood flow (ml/min) was calculated from mean blood flow velocity and cross-sectional area. RESULTS: Increasing concentrations of nitroglycerin led to a dose-dependent increase in radial artery diameter (maximal +24 +/- 2%) and heart rate. Forearm vascular resistance and forearm blood flow were unchanged. After 24 and 48 h of treatment, additional nitroglycerin did not further increase radial artery diameter, indicating that the nitroglycerin-induced dilation of the radial artery was maintained and was still maximal. In addition, radial artery diameter measured before and after 48 h of nitroglycerin infusion and after withdrawal of nitroglycerin in five additional patients showed that, after withdrawal, arterial diameter returned to baseline values within 35 min. Plasma renin activity and serum aldosterone and vasopressin levels increased significantly at 24 and 48 h, accompanied by a decrease in hematocrit. CONCLUSIONS: Continuous intravenous administration of nitroglycerin exerts a sustained vasodilator effect for 48 h in large conductance vessels. Neurohormonal activation and compensatory intravascular volume expansion do not attenuate the vasodilator effects of nitroglycerin on peripheral conductance vessels during the 1st 48 h of treatment.


Assuntos
Doença das Coronárias/fisiopatologia , Nitroglicerina/farmacologia , Vasodilatação/efeitos dos fármacos , Adulto , Idoso , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Relação Dose-Resposta a Droga , Tolerância a Medicamentos , Feminino , Humanos , Infusões Intravenosas , Masculino , Pessoa de Meia-Idade , Nitroglicerina/administração & dosagem , Artéria Radial/efeitos dos fármacos
19.
Lancet ; 339(8792): 561, 1992 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-1346916
20.
Z Kardiol ; 79(10): 677-82, 1990 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-2087854

RESUMO

Impaired ventricular diastolic filling may be an early sign of myocardial ischemia. To study the influence of coronary angioplasty (PTCA) on diastolic filling, 40 patients with coronary heart disease (CHD) were studied by pulsed two-dimensional Doppler echocardiography (2DDE) before and after PTCA. In six patients PTCA was not successful and 2DDE indices of ventricular filling did not change significantly. In 34 patients with successful PTCA, peak early diastolic velocity (E) increased by 8.5% (p less than 0.03), the ratio (E/A) of peak early vs peak late diastolic velocity by 11.2% (p less than 0.005) and the diastolic filling time per minute (diast.-t/min) by 4.6% (p less than 0.01). In patients with impaired diastolic filling before PTCA (group I, n = 28) the changes in diastolic filling were even more pronounced. Patients with unimpaired diastolic filling properties before PTCA did not show significant alterations (group II, n = 6). Seventeen patients were examined 3 h and 24 h after PTCA. The changes in diastolic filling parameters apparent already 3 h after PTCA were even more pronounced after 24 h. According to these data, PTCA improves left ventricular diastolic filling. These changes are more pronounced 24 h compared to 3 h after PTCA.


Assuntos
Angioplastia Coronária com Balão , Doença das Coronárias/fisiopatologia , Diástole/fisiologia , Ecocardiografia Doppler/métodos , Hemodinâmica/fisiologia , Função Ventricular Esquerda/fisiologia , Adulto , Idoso , Velocidade do Fluxo Sanguíneo/fisiologia , Doença das Coronárias/terapia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade
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