Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors describe the clinical characteristics and response to therapy of seven patients with hyperthyroidism, dilated cardiomyopathy, and low-output cardiac failure. All patients (4 women and 3 men, age 47 +/- 4 years, mean +/- standard error of the mean) were admitted with the primary diagnosis of congestive heart failure. The cause of hyperthyroidism was Graves' disease in six patients, and toxic multinodular goiter in one. On admission, the mean serum T4 was 21 +/- 1 microgram/dL and mean serum T3:411 +/- 77 ng/mL, and serum thyroid-stimulating hormone was suppressed ( < 0.03 microU/mL) in all patients. Two-dimensional echocardiogram showed biventricular or four chamber dilatation and impaired left ventricular performance. Therapy of heart failure and hyperthyroidism resulted in rapid clinical improvement. During follow-up (5 months to 9 years), left ventricular ejection fraction improved from a mean of 28% to a mean ejection fraction of 55% (P < 0.01). Resolution of dilated cardiomyopathy with normalization of systolic function was achieved in five patients, and improvement from severe to mild left ventricular dysfunction was observed in two patients. We conclude that some patients with hyperthyroidism may have a reversible form of dilated cardiomyopathy and "low-output failure." Assessment of thyroid hormone status in patients with heart failure might permit the identification of patients with dilated cardiomyopathy and thyrotoxicosis who are likely to have reversible cardia dysfunction.
 ...
PMID:Congestive heart failure due to reversible cardiomyopathy in patients with hyperthyroidism. 766 12

To accurately evaluate thyroid disorders in pregnancy, the physician must understand the physiologic changes that occur both in thyroid gland size and in thyroid function tests. The effect of thyrotoxicosis on pregnancy outcome largely depends on whether metabolic control is achieved. Women who become euthyroid on treatment usually can expect satisfactory outcomes. Propylthiouracil is considered to be the drug of choice for treating thyrotoxicosis during pregnancy. Because of the significant risk of hypothyroidism and obvious goiter in the infant, the use of iodide should be reserved for severe disease, such as thyroid storm or heart failure. Thyrotoxic infants may need antithyroid treatment until TSAbs are metabolized. Since overt hypothyroidism is often associated with infertility, it is uncommon in pregnancy. Hypothyroid women who do become pregnant, however, have an increased risk of low-birth-weight or stillborn infants. These women may require a greater dosage of thyroid hormone during pregnancy. The effects of subclinical hypothyroidism are not well defined. Accordingly, the need for treatment hinges on the woman's clinical history. Infants of hypothyroid mothers usually show no evidence of thyroid dysfunction, but those who are hypothyroid should receive prompt thyroid replacement therapy. To minimize the sequelae of congenital hypothyroidism, mass screening of infants and prompt treatment of those affected is recommended. During pregnancy, thyroid nodules should be evaluated by ultrasound and fine-needle aspiration or tissue biopsy. Radioiodine scanning should be avoided during pregnancy. If thyroid cancer is diagnosed, pregnancy should not delay treatment. Because postpartum thyroid dysfunction is fairly common yet difficult to detect, physicians and patients should be aware of the symptoms and risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Thyroid disease in pregnancy. ACOG Technical Bulletin Number 181--June 1993. 790 64

The effects of spontaneous and experimentally induced congestive heart failure on serum thyroxine (T4), 3,5,3'-triiodothyronine (T3), 3,3'5'-triiodothyronine (reverse T3), free T4, free T3 concentrations, and the serum T4 and T3 concentrations in response to administration of thyrotropin were studied. Serum thyroid hormone concentrations were not different between eight dogs with spontaneous congestive heart failure and normal age matched control dogs. Seven dogs with experimental heart failure were tested before and after induction of congestive heart failure by rapid ventricular pacing. Mean serum T4 and free T3 concentrations were decreased and mean serum reverse T3 concentration was increased following induction of heart failure. The serum T4 and T3 responses to thyrotropin were not altered. Thyroid gland morphology appeared normal in dogs with experimental heart failure. Experimental congestive heart failure, similar to some other nonthyroidal illnesses, alters thyroid hormone secretion and metabolism in dogs.
 ...
PMID:Thyroid function in dogs with spontaneous and induced congestive heart failure. 795 15

In this paper the authors have evaluated the incidence and the clinical implications of sick euthyroid syndrome (SES) in a group of 144 patients in a department of internal medicine. SES is an alteration of thyroid hormone values in the absence of a thyroid disease, which is seen in patients suffering from serious diseases. Having classified SES into 3 subgroups according to the different alterations seen in the values of T3, T4, FT3, FT4, TSH, rT3 and TBG, they show the hypotheses that explain the biochemical mechanisms which are at the basis of these hormonal alterations. Fourteen of the 144 patients under observation were excluded as they were suffering from ascertained or subclinical thyroid disease. Thirty (23% of cases) of the remaining 130 patients had alterations of the thyroid hormones in accordance with SES diagnosis. Of these 30 patients, 19 had hormone values found in SES type I (63%), 2 in SES type II (6.5%) and 9 in SES type III (30.5%). In SES type I the diseases seen, in order of frequency, were: obstructive chronic bronchopneumopathy with acute respiratory failure, diabetic ketoacidosis, neoplasms, ischemic heart disease, cardiac failure, chronic renal failure, liver diseases, acute cerebral vasculopathies, sepsis and collagenopathies. The disease seen in the 2 cases of SES type II was obstructive chronic bronchopneumopathy with acute respiratory failure. In SES type III the diseases seen were, in order of frequency: diabetic ketoacidosis, lung diseases, ischemic heart disease, cardiac failure, peripheral arteriopathies, acute cerebral vasculopathies, neoplasms, liver diseases, acute renal failure. The incidence of SES in 23% of the admitted to hospital patients was found to be slightly higher than in other studies; this could be explained by a stricter selection of inpatients: in fact self-sufficient patients or those not needing urgent admission, were sent to an efficient out patient clinic where necessary examinations were quickly carried out, hospitalization being reserved for patients with more serious illnesses. We would like to underline how the incidence of SES is much greater than that of what is known as thyroid disease (23% compared to 5%), thereby confirming that it is the most frequent cause of alterations of thyroid hormones. With regard to the pathogenetical hypotheses, it is confirmed that in SES, the reduction of T3 values is accompanied by an increase in the values of rT3 as for reduced activity of 5-desiodinasis enzyme. In SES type III the increase of T4 values is due to the increase of TBG resulting in an increase in the link for T4 and therefore a reduced peripheral hormone activity.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:[The euthyroid sick syndrome. Its incidence and clinical significance in an internal medicine department]. 802 42

Thyroid disease is common in veterinary practice. The heart, especially the myocardium, is sensitive to thyroid hormone, and deficiencies or excesses can alter cardiovascular function. Observed changes result from direct effects upon the myocardium and indirect effects that result from effects upon the vasculature and peripheral tissues. Clinically significant cardiovascular abnormalities related to hypothyroidism are rare. If present, they are primarily manifest as reduced left ventricular pump function, as apparent echocardiographically, or arrhythmias. Hyperthyroidism is common in the cat and infrequently encountered in dogs. Clinically significant cardiovascular manifestations are common and often dramatic. Hyperdynamic systolic function and mild myocardial hypertrophy are common manifestations which may lead to overt congestive and high output heart failure. If signs of congestive heart failure or significant arrhythmias are not evident, specific therapy need only be directed toward restoration of the euthyroid state. In most cases the cardiovascular changes associated with thyroid dysfunction are completely reversible.
 ...
PMID:Effects of thyroid hormone and thyroid dysfunction on the cardiovascular system. 805 9

The relationship between cardiac function and serum thyroid hormone levels was investigated in 41 patients with chronic heart failure (25 men and 16 women, mean age 63.7 +/- 11.1 years) and 15 normal subjects (5 men and 10 women, mean age 55.5 +/- 12.2 years). Patients with apparent thyroid disease were excluded from the study. All patients were evaluated according to the New York Heart Association (NYHA) classification using echocardiography, cardiothoracic ratios, mean daily heart rates calculated from ambulatory electrocardiograms (ECG), and ventricular tachyarrhythmias greater than triplets based on either Holter or ECG monitoring. The serum free triiodothyronine (FT3), free thyroxine (FT4), and reverse triiodothyronine (rT3) levels were measured. Decreased FT3 levels and FT3/FT4 ratios, and increased rT3 levels were associated with worse NYHA class. FT3/FT4 was positively and rT3 was negatively correlated with echocardiographical fractional shortening. FT3 and rT3 were negatively and positively correlated with mean daily heart rates, in contrast to known hypothyroid patients. Patients with ventricular tachycardia demonstrated significantly lower serum values of FT3 and FT3/FT4, and significantly higher values of rT3. Serum thyroid hormone levels can provide a quantitative index for evaluating the severity of chronic heart failure and predicting ventricular tachycardia.
 ...
PMID:[Serum thyroid hormone levels correlate with cardiac function and ventricular tachyarrhythmia in patients with chronic heart failure]. 817 32

We report 4 adult patients with thyrotoxicosis accompanied by irreversible low-output heart failure. Each patient showed elevated plasma levels of thyroid hormone and prolonged low-output heart failure even after thyroid function returned to normal. Specimens of the right ventricular myocardium stained with anti-beta myosin heavy-chain MAb showed a normal staining pattern with a predominance of the beta-form. Our observations suggest that thyrotoxicosis may be one possible cause of irreversible cardiomyopathy.
 ...
PMID:Irreversible cardiomyopathy due to thyrotoxicosis. 818 12

The mechanisms of actions of thyroid hormone in various tissues are largely viewed as cell nucleus-mediated. However, several actions of this hormone are definitively extranuclear, and these include effects on the activities of Ca(2+)-adenosine triphosphatases (ATPases) of myocardial sarcolemma and, apparently, sarcoplasmic reticulum in animal models. Both effects would serve to reduce cytoplasmic (sarcoplasmic) [Ca2+]. Sarcoplasmic reticulum uptake of Ca2+ from sarcoplasm is mediated by Ca(2+)-ATPase and is deficient in end-stage heart failure; thyroid hormone can enhance sarcoplasmic reticulum Ca(2+)-ATPase activity acutely via an extranuclear mechanism or indirectly via the myosin-associated Ca(2+)-ATPase gene. Such actions would serve to improve myocardial relaxation, thus improvement in diastolic dysfunction, and may be cardioprotective if excessive levels of sarcoplasmic [Ca2+] develop during reperfusion of previously ischemic tissue. Action of thyroid hormone on sarcolemmal Ca(2+)-ATPase activity will enhance Ca2+ efflux, and a recently described effect of the hormone on myocardial Na+ inactivation current may serve to increase or reduce sarcoplasmic [Ca2+], depending upon the vector of Na+/Ca2+ exchange. This article reviews acute effects of thyroid hormone on the heart that are extranuclear in mechanism.
 ...
PMID:Acute cellular actions of thyroid hormone and myocardial function. 833 93

In heart failure, cardiac output is insufficient to meet the needs of the body for oxygen delivery. Available data suggest that alterations in thyroid hormone metabolism may contribute to defective myocardial performance. Accordingly, thyroid hormone or a thyroid hormone analogue that improves cardiac performance might be useful in the treatment of heart failure and has been studied. Experimental and theoretical results of these studies are reviewed and indicate that thyroid hormone increases cardiac output by a combination of effects on the heart and peripheral circulation, specifically by increasing myocardial contractile performance and decreasing venous compliance. In the rat postinfarction model of heart failure, treatment with low doses of thyroxine (1.5 micrograms/100 g) for 3 days produced a positive inotropic response, including an increase in rate of change of left ventricular pressure and a decrease in left ventricular end-diastolic pressure. These changes could be attributed to conversion to triiodothyronine, the active intracellular form of thyroid hormone. When treatment with thyroxine was continued at the same or higher doses (3 to 15 micrograms/100 g) for 10 to 12 days, heart rate increased and improvement in left ventricular end-diastolic pressure was not sustained. More favorable results were obtained with 3,5-diiodothyropropionic acid, a cardiotonic thyroid hormone analogue administered at doses of 375 microgram/100 g, given in combination with captopril. Thus, triiodothyronine or a thyroid hormone analogue may be a useful adjunct to other measures in the treatment of heart failure.
 ...
PMID:Studies on the use of thyroid hormone and a thyroid hormone analogue in the treatment of congestive heart failure. 833 98

The effects of acute and chronic administration of propranolol and verapamil on heart rate and systolic time intervals were studied in 10 hyperthyroid patients and 10 normal subjects, both groups without signs of cardiovascular or pulmonary disease. In normal subjects iv propranolol reduced heart rate significantly, and both drugs increased the total electromechanical systole significantly without difference between the drugs. This effect was insignificant when the drugs were given orally. In hyperthyroid patients both drugs reduced heart rate significantly in acute and chronic administration, and no difference between the two drugs was found. Neither drug altered cardiac contractility as assessed by systolic time intervals. These results indicate that the metabolic effects of thyroid hormone on contractility were unaltered and unblocked by the drugs. None of the participants developed signs of heart failure. Verapamil can thus be used as an alternative to propranolol in the treatment of tachycardia in hyperthyroidism.
 ...
PMID:The effects of propranolol and verapamil on hyperthyroid heart symptoms and function, assessed by systolic time intervals. 849 48


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>