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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thyroid hormones have been shown to be absolutely necessary for early brain development. During pregnancy, both maternal and foetal thyroid hormones contribute to foetal brain development and maternal supply explains why most of the athyreotic newborns usually do not show any signs of hypothyroidism at birth. Foetal and/or neonatal hypothyroidism is a rare disorder. Its incidence, as indicated by neonatal screening, is about 1:4000. Abnormal thyroid development (i.e. agenesia, ectopic gland, hypoplasia) or inborn errors in thyroid hormone biosynthesis are the most common causes of permanent congenital hypothyroidism. Recent studies reported that mutations involving Thyroid Transcriptor Factors (TTF) such as TTF-1, TTF-2, PAX-8 play an important role in altered foetal thyroid development. Deficiency of transcriptor factor (Pit-1, Prop-1, LHX-3) both in mother and in the foetus represents another rare cause of foetal hypothyroidism. At birth clinical picture may be not always so obvious and typical signs appear only after several weeks but a delayed diagnosis could have severe consequences consisting of delayed physical and mental development. Even if substitutive therapy is promptly started some learning difficulties might still arise suggesting that intrauterine adequate levels of thyroid hormones are absolutely necessary for a normal neurological development. Placental transfer of maternal antithyroid antibodies inhibiting fetal thyroid function can cause transient hypothyroidism at birth. If the mother with thyroid autoimmune disease is also hypothyroid during pregnancy and she doesn't receive substitutive therapy, a worse neurological outcome may be expected for her foetus. Foetal and/or neonatal hyperthyroidism is a rare condition and its incidence has been estimated around 1:4000-40000, according to various authors. The most common causes are maternal thyroid autoimmune disorders, such as Graves' disease and Hashimoto's thyroiditis. Rarer non autoimmune causes recently identified are represented by TSH receptor mutations leading to constitutively activated TSH receptor. Infants born to mothers with Graves' history may develop neonatal thyrotoxicosis. Foetal/neonatal disease is due to transplacental thyrotrophin receptor stimulating antibodies (TRAb) passage. It's extremely important recognizing and treating Graves' disease in mothers as soon as possible, because a thyrotoxic state may have adverse effects on the outcome of pregnancy and both on the foetus and newborn. Thyrotoxic foetuses may develop goitre, tachycardia, hydrops associated with heart failure, growth retardation, craniosynostosis, increased foetal motility and accelerated bone maturation. Neonatal Graves' disease tends to resolve spontaneously within 3-12 weeks as maternal thyroid stimulating immunoglobulins are cleared from the circulation but subsequent development may be impaired by perceptual motor difficulties. Hashimoto's thyroiditis is a very common autoimmune thyroid disease. In presence of maternal Hashimoto's thyroiditis, there are usually no consequences on foetal thyroid, even if antiTPO and antiTg antibodies can be found in the newborn due to transplacental passage. However there are some literature reports describing foetal and neonatal hyperthyroidism in the affected mothers' offspring.
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PMID:Foetal and neonatal thyroid disorders. 1224 77

Mutations of the TSH receptor leading to constitutive activation of the cAMP cascade are responsible for the development of hot nodules, if arising in a somatic cell, and nonautoimmune hyperthyroidism, when occurring in a germinal cell. An animal model of constitutive activation of the thyroid cAMP cascade has been obtained by generating transgenic mice expressing the adenosine receptor (Tg-A2aR) under the control of the thyroglobulin promoter. These mice develop huge goiters and die prematurely due to hyperthyroidism induced cardiac failure. To identify new genes involved in the tumorigenic pathway of the thyroid, we designed a protocol using microarray technology to study the differential expression, between normal and transgenic thyroid, of +/-13,000 genes. A total of 360 genes or expressed sequence tags showed a strong modulation with background corrected values of fluorescence superior to 2-fold change. The modulated genes were classified according to their proposed gene ontology functions. Approximately half of them were up-regulated. The function of the majority of these genes in thyroid physiology is still to be determined. Some of them, like IGF-I or IGF binding protein 3 or 5, may play an important role in the development of thyroid nodules through paracrine mechanisms. This study demonstrates the feasibility of sequentially following the cascade of events leading to the formation of benign tumors such as hot thyroid nodule or hyperfunctional goiter.
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PMID:Gene expression profile in thyroid of transgenic mice overexpressing the adenosine receptor 2a. 1456 36

First cause of hyperthyroidism among women of childbearing age, Graves' disease raises the risk of maternal and fetal complications, including eclampsia, cardiac failure, abortion, prematurity, fetal death, all of which can be avoided if maternal hyperthyroidism is closely controlled. The risk of transplacental hyperthyroidism has been shown to correlate to the titre of anti-TSH receptor antibodies and has to be evaluated not only in women treated for Graves' disease during pregnancy, but also in women who have previously received radio iodine treatment or undergone surgery for Graves' disease: TSH-receptor antibodies may indeed remain at a high level several years after initial treatment. Both methimazole and propylthiouracil are equally effective to restore maternal euthyroidism. Accumulation of case-reports relating congenital malformations (mostly aplasia cutis, but in some cases, severe malformations) among the offspring of methimazole-treated women suggests the possibility of a teratogenic effect of methimazole. Despite the fact that the link between severe congenital defects and methimazole exposure during pregnancy is not formally established, propylthiouracil should be preferred to methimazole for the treatment of young hyperthyroid women.
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PMID:[Antithyroid agents and embryopathies]. 1506 47

The abundance of published data on the neonatal effects of maternal Graves' disease (GD) contrasts with the paucity of information on fetal effects. In our yet unpublished study, we prospectively studied 72 pregnant women with a history of Graves' disease. Fetal ultrasonography was done at 22 and 32 weeks of gestational age. Fetal goiter was found at 32 weeks in 11 of the fetuses of the 41 mothers with positive TSH-receptor antibodies and/or antithyroid treatment and in none of the fetuses of the 31 other mothers. In the 11 fetuses with goiter, ultrasound findings (thyroid Doppler and bone maturation), fetal heart rate, and maternal antibody and antithyroid drug status effectively discriminated between hypothyroidism (n=7) and hyperthyroidism (n=4). One fetus with hyperthyroidism died in utero at 35 weeks from heart failure. Treatment was successful in the ten other fetuses. One fetus without goiter had moderate hypothyroidism at birth. This study showed that it is of the utmost importance to have the fetal thyroid scrutinized by an expert ultrasonographist and to have team work with obstetricians and paediatric endocrinologists in pregnant mothers with GD. This allowed us to accurately determine fetal thyroid status and to adapt the treatment in mothers successfully. Fetal hyperthyroidism does exist and needs an appropriate aggressive treatment.
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PMID:Fetal and neonatal thyroid function in relation to maternal Graves' disease. 1515 41

The clinical manifestations of thyroid diseases in the elderly are often atypical and can easily be attributed to other medical conditions or 'normal aging'. Two nursing home patients with hyperthyroidism are described. Due to the atypical presentation of the thyroid disease their complaints were attributed to other conditions. In both patients there was a significant delay in diagnosis and treatment of hyperthyroidism. In elder patients signs and symptoms of thyreotoxicosis are frequently related to cardiovascular, gastrointestinal and neuropsychiatric disorders. Most often occur atrial fibrillation, worsening of cardiac failure and angina pectoris, weight loss, anorexia, constipation, cognitive impairment and delirium. Delay of diagnosis and treatment of hyperthyroidism may be potentially harmful to the patient. Untreated thyreotoxicosis may lead to serious cardiovasculair complications (particularly cardiac failure and cerebrovascular accidents), mental deterioration and osteoporosis. In elder people with unexplained and vague signs and symptoms thyroid function should always be checked. The TSH assay is a very accurate diagnostic test for screening thyroid function. A normal TSH indicates euthyroidism with an accuracy of almost 100%. The medical treatment for hyperthyreoidism in the elderly are antithyroid drugs. When an euthyroid state is rendered, suppletion with L-thyroxine may be nessecary. Radioactive iodine treatment is preferred in some cases though there may be practical difficulties with the application of this treatment in nursing home patients because temporary isolation is necessary.
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PMID:[Hyperthyroidism in the elderly: aspecific signs may cause a delay in diagnosis]. 1594 73

A 74 year-old man was admitted to the hospital for heart failure and atrial fibrillation episodes. He had been irregularly treated for hyperthyroidism during the previous 3 years, with poor control. Thyroid function evaluation showed secondary hyperthyroidism, with high free thyroid hormone levels and TSH inappropriately in the high-normal range (4.2 mU/ml), only slightly responsive to TRH-stimulation (6 microU/ml). Alpha-subunits were hyper-responsive to TRH stimulation (+123%). Thyroid autoimmunity tests were negative and ultrasonography evidenced a diffusely enlarged gland. Magnetic resonance (MR) imaging of the pituitary showed a macroadenoma. The patient underwent transphenoidal adenomectomy, and immunohistochemistry confirmed the diagnosis of a TSH-secreting pituitary macroadenoma. A moderate secondary hyperthyroidism was still present and a new MR evidenced residual disease, involving the right cavernous sinus. A (111)In-octreoscan revealed an increased captation in this area. The patient was treated with octreotide-Lar (20 mg/monthly), which normalized FT3, FT4 and TSH levels already after 3 months of therapy. This effect is still maintained at 42 months of treatment. MR imaging showed a reduction in the residual lesion after 18 months (>50% in comparison with postsurgical MR) and a further decrease after 36 months of treatment). This suggests that the antiproliferative effect on the adenomatous cells is progressive and continues over time. This patients did not receive radiotherapy, so this action is entirely due to the medical treatment. No significant side effects developed and the patient's compliance was good. He has not had further arrhythmic episodes.
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PMID:[Effect of long-term treatment with octreotide-lar in a TSH-secreting pituitary macroadenoma and secondary hyperthyroidism]. 1598 5

Growing evidence suggests that thyroid dysfunction may contribute to progression of cardiac disease to heart failure. We investigated the effects of a therapeutic dose of thyroid hormones (TH) on cardiomyopathic (CM) hamsters from 4 to 6 mo of age. CM hamsters had subclinical hypothyroidism (normal thyroxine, elevated TSH). Left ventricular (LV) function was determined by echocardiography and hemodynamics. Whole tissue pathology and isolated myocyte size and number were assessed. TH treatment prevented the decline in heart rate and rate of LV pressure increase and improved LV ejection fraction. The percentage of fibrosis/necrosis in untreated 4-mo-old CM (4CM; 15.5 +/- 2.2%) and 6-mo-old CM (6CM; 21.5 +/- 2.4%) hamsters was pronounced and was reversed in treated CM (TCM; 11.9 +/- 0.9%) hamsters. Total ventricular myocyte number was the same between 4- and 6-mo-old controls but was reduced by 30% in 4CM and 43% in 6CM hamsters. TH treatment completely prevented further loss of myocytes in TCM hamsters. Compared with age-matched controls, resting and maximum coronary blood flow was impaired in 4CM and 6CM hamsters. Blood flow was completely normalized by TH treatment. We conclude that TH treatment of CM hamsters with subclinical hypothyroidism normalized impaired coronary blood flow, which prevented the decline in LV function and loss of myocytes.
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PMID:Treatment of subclinical hypothyroidism reverses ischemia and prevents myocyte loss and progressive LV dysfunction in hamsters with dilated cardiomyopathy. 1602 68

Chronic heart failure (CHF) is a global disease in which beside renin-angiotensin-aldosterone (RAA) system most endocrinal glands are affected. The occurrence of these disorders depends on the degree of heart failure. The influence on prognosis and therapeutic strategy is not known. The aim of this study was to evaluate the frequency of secretion disturbances of chosen hormones: prolactin (PRL), testosterone (TTE), thyroid hormones fT3, fT4 and TSH in a group of male in NYHA functional class II-IV and left ventricular ejection fraction less than 35% dependently on clinical degree of CHF and left ventricular defect. 27 male aged 35-83 years (mean 55,4) with different etiology of heart failure were enrolled in to the study. 3 groups (A, B, C) were selected dependently on NYHA class-group A - NYHA II (9), B - NYHA III (8), C - NYHA IV (10) and D group of healthy volunteers. 3 other groups were selected accordingly to left ventricular ejection fraction - I - 30-35% (14), II - 20-29% (8), III - <20% (5), IV - normal ventricular ejection fraction (10). The immunofluorescent tests were used for measuring chosen hormones concentration in blood serum. In 14 from 27 (52%) hormonal disturbances were found. No changes were noted in group A. All noted disturbances were observed in group B and C (NYHA class III/IV) more frequent in group C (90%) vs B (75%). This relation was not observed in connection with left ventricular ejection fraction. Elevated serum PRL (8) and decreased TTE concentration (5) were the most frequent hormone changes in whole study group. Results of this study confirm that CHE is often accompanied by disturbances in endocrinal glands secretion. The frequency of these disturbances rises with the degree of clinical advance of CHF.
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PMID:[Prolactin (PRL), thyrotropin (TSH), free thyroid hormones (fT4), (fT3) and testosterone (TTE) level in men with chronic heart failure]. 1620 45

We report a case of a 70-year-old female with considerable co-morbidities (Type 2 diabetes, Leiden factor V mutation, mild to moderate chronic obstructive pulmonary disease) and a recent biological aortic valve substitution, who was admitted due to circulatory collapse caused by severe heart failure with an ejection fraction of 10%. The patient was treated with diuretics and inotropic drugs with only a minor effect on the condition. A thyroid status disclosed a condition of overt hypothyreosis (TSH: 70 miu/L, T4: 19 nmol/L, T3 0.8: nmol/L). Cautious treatment with peroral Levothyroxin and hydrocortisone was given as a supplement to the heart failure treatment and the condition improved gradually. Within 3 months the patient was euthyroid and had regained her habitual LV function.
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PMID:Heart failure after aortic valve substitution due to severe hypothyroidism. 1766 92

The literature on the effect of excess thyroid hormone on ventricular repolarization is controversial. To study whether free thyroxine (T(4)) and TSH are associated with QTc prolongation we conducted population-based cohort study. This study was conducted as part of the Rotterdam Study and included 365 men and 574 women aged 55 years and older with an electrocardiogram, who were randomly sampled for the assessment of thyroid status (free T(4)/TSH) at baseline, after exclusion of participants with hypothyroidism, use of antithyroid drugs, thyroid hormones or digoxin, left ventricular hypertrophy, and left and right bundle branch block. Endpoints were the length of the QTc interval and risk of borderline QTc prolongation. The associations were examined by means of linear and logistic regression analysis, adjusted for age and gender, diabetes mellitus, myocardial infarction, hypertension, and heart failure. Overall, there was no significant association between TSH and QTc interval (0.8 ms (95% confidence interval (CI) -3.5, 5.2) in the first quintile compared with the fifth quintile). Subjects in the fifth quintile of free T(4) did not have an increased QTc interval (3.2 ms (95% CI -1.1, 7.6)); stratification on gender showed an increment of 10.9 ms (95% CI 3.4, 18.3) in the fifth quintile in men and 1.1 ms (95% CI -4.2, 6.3) in the fifth quintile of free T(4) in women. When compared with subjects in the first quintile, male subjects in the fifth quintile of free T(4) had a significantly increased risk of a borderline QTc interval and QTc prolongation (odds ratio 2.40 (95% CI 1.20, 4.80)). High levels of free T(4) are associated with substantial QTc prolongation in men of up to 10 ms. The fact that free T(4) is also associated with a significantly increased risk of borderline and prolonged QTc values with its risk of sudden cardiac death, endorses the clinical importance of our findings.
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PMID:High free thyroxine levels are associated with QTc prolongation in males. 1846 46


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