From Big Medical Encyclopedia

THYROTOXICOSIS [lat. (glandula) of thyreoidea thyroid gland + toxicosis; synonym: tirotoksikoz, hyperthyroidism] — the morbid condition of an organism caused by the increased content in blood of hormones of a thyroid gland. T. is not an independent disease, and represents the symptom complex obligatory at a diffusion toxic craw (see. Craw diffusion toxic ), including developed owing to hormonal and active adenoma hypophysis (see), cosecreting thyritropic hormone (see), a multinodal hyper thyroid craw (see. Craw sporadic ) and thyrocardiac adenoma (see. Thyroid gland ); sometimes T. develops at subacute thyroiditis (see). Less often the T meets., the caused excess introduction to an organism of prelarat of hormones of a thyroid gland — thyroxine (see) and triiodothyronine (see), used for replacement therapy at a hypothyroidism (see), after a strumectomy, a subtotal resection of a thyroid gland, etc.

T. can arise for the first time both in the period of a neonatality, and at more advanced age or even at adults; predisposition to a disease remains throughout all life.

The concept «thyrotoxicosis» was connected with a diffusion toxic craw earlier, then also other diseases which are followed by T. Lish in 1961 were described. The term «craw diffusion toxic» was entered by the international congress of the socialist countries on a problem of a local craw into a wedge, classification of diseases of a thyroid gland, and T. it was accurately defined as the complex of symptoms caused by excess of thyroid hormones in blood.

In a wedge, the practician T. on degree of manifestation of symptoms divide on easy, moderately severe, heavy. Wedge, manifestations of T. do not depend on genesis of a disease.

The patients suffering from T., show complaints to an acrimony, feeling of concern, fear, a sleep disorder, perspiration, a tremor of fingers of hands, language, all trunk, bad portability of elevated temperature of the environment, tachycardia, sometimes to pain in heart of the pricking or squeezing character, an exophthalmos, diarrhea, nausea, vomiting, weight reduction of a body, a hyporexia (at easy for T. and T. moderately severe appetite is often increased). The abnormal liver function at first is almost not noted, however at increase of symptoms of T. the liver increases, in blood concentration increases bilirubin (see), can appear jaundice (see). At long and heavy T. the hypocorticoidism is observed (see. Adrenal glands ), dysfunction of gonads (women have a dysmenorrhea and akhmenoreya, and men — decrease in a sexual potentiality, a gynecomastia), is described emergence of symptoms of so-called thyrogenic diabetes (see. Diabetes, table ).

Almost at all patients with T. note decrease in mental activity, an adynamy (see. Asthenic syndrome ), frustration of the emotional sphere, etc.

Standard metabolism (see) at a severe form of T. reaches 100%, the coefficient of effective thyroxine (CET) is increased to 1,13 (this indicator testifies to the general concentration of thyroxine in blood and to tiroksinsvyazyvayushchy ability of blood proteins). Strengthening of exchange and a catabolism of proteins at is long flowing T. leads to development osteoporosis (see) as a result of loss of the main substance of a bone — osseomucoid.

In cardiovascular system at T. the complex of disturbances which received the name «thyrocardiac heart» develops. The term is offered in 1899 by R. Kraus. At influence of excess amount of thyroid hormones metabolic disturbances in a myocardium are characterized by dissociation of tissue respiration and oxidizing phosphorylation (see. biological oxidation ), reduction of number of vysokoergichesky connections (see), decrease in intensity of synthesis and strengthening of an albuminolysis, heterogeneity of electric potential of a myocardium (see Heart). Hemodynamic disturbances are characterized by tachycardia, increase in speed of a blood-groove and volume of the circulating blood. Quite often strengthening of cardiac sounds, systolic noise come to light, increase in a left ventricle, and later and all heart is preferential on a top of heart.

Cardinal symptom of T. is tachycardia (see), heart rate is directly proportional to weight of T. Takhisistolicheskaya a form of atrial fibrillation (see. The ciliary arrhythmia) in the form of paroxysms or a constant is observed at patients of middle and advanced age with a severe form T. Vydelyayut a special form T., shown attacks of a takhisistolichesky form of atrial fibrillation against the background of a normal rhythm or bradycardia (see) almost in the absence of symptoms of a toxic craw. The major diagnostic importance in this case has strengthening of thyroid hormones in blood during a paroxysm of a ciliary arrhythmia.

At patients with T. against the background of a toxic craw can appear stenocardia (see), especially at patients with coronary heart disease (see), the patients with a toxic craw. The stenocardia which arose against the background of T., the wedge, displays of a toxic craw depends on weight, does not depend on age of patients, equally often has character of an angina of exertion and stenocardia of rest; the myocardial infarction develops seldom. Stenocardia at a toxic craw is not a contraindication to a subtotal resection of the goitrous changed thyroid gland.

The developed picture of disturbance of blood circulation at patients with T. it is generally presented by right ventricular insufficiency. Lack of effect of use of cardiac glycosides is characteristic (see) without simultaneous treatment by anti-thyroid means.

In process of development of T. there occur changes of an ECG, to-rye are expressed by increase in a voltage of the QRS complex, mistakenly treated sometimes as signs of a hypertrophy of a myocardium of a left ventricle in the beginning. These changes are connected with the hyperfunction of a myocardium aggravating his dystrophy (see the Myocardial dystrophy) that in the subsequent is expressed by decrease in a voltage of teeth, change of a final part of a ventricular complex — the shift of a segment S — the T is lower isolines and decrease or inversion of a tooth of T. These changes are reversible after effective treatment and are not a contraindication to a subtotal resection of a thyroid gland. Almost at 1/3 patients after operation on pshchtovidny gland on an ECG the negative tooth of T is registered, to-ry it is caused by stressful reaction to an operative measure. As a rule, in 10 — 14 days after operation ECG it is normalized.

The diagnosis of thyrocardiac heart is difficult if in a picture T. the phenomena characteristic of heart disease prevail (see. Heart diseases ). In these cases definition of concentration of thyroid hormones in blood is necessary. With the diagnostic purpose it is possible to carry out trial treatment (30 — 40 mg of mercazolil a day within 2 — 3 weeks; 50 — 60 mg of mercazolil a day within 1 month in the presence of atrial fibrillation), however trial treatment by thyreostatic means insufficiently informatively.

Treatment of cardiovascular frustration at patients with T. symptomatic, it is carried out on condition of obligatory simultaneous specific treatment by antitireo-idny means.

Symptoms of T. reach a maximum at thyrocardiac crisis (see. Crises ). The term «thyrocardiac crisis» (thyrogenic crisis, hyper thyroid crisis, bazedova of a lump) appeared in 1930 in B. Tsondek's works. Thyrocardiac crisis is observed approximately at 1% of patients with T. and most often develops at people with an uncured diffusion toxic craw or at not enough treated patients who especially have serious associated diseases. Thyrocardiac crisis can be provoked by mechanical manipulations on a thyroid gland during operation (so-called postoperative thyrocardiac crisis) or at survey and a palpation of gland, a stressful situation, etc. Sometimes the reason of thyrocardiac crisis does not manage to be established. Development of crisis testifies about heavy, predictively the adverse course of the disease which is followed by T.

Concerning a pathogeny of thyrocardiac crisis there is no consensus. There are various concepts explaining its emergence; the theory has the greatest number of supporters, according to a cut thyrocardiac crisis is caused by additional increase in blood just before crisis and at the beginning of it concentration of thyroid hormones, including their free fraction.

An important pathogenetic factor of development of thyrocardiac crisis is relative adrenal insufficiency at is long flowing T., what is confirmed by effective therapy of this state with corticosteroid drugs (see Corticosteroids). Participation of sympathoadrenal system (see) in a pathogeny of thyrocardiac crisis comes down to the fact that the processes and symptoms mediated by it make only a part (and smaller) the diverse and difficult disturbances inherent in T.

At thyrocardiac crisis observe increase in activity kallikrein — kinin system (see. Kinina ), what is followed by increase in content in blood serum of bradikinin, a kininogen, increase in activity of a kininogenaza (KF and other components of this system.

The highest expression of thyrocardiac crisis — a lump (see). In detail a wedge, a picture and treatment of thyrocardiac crisis — see. Crises, thyrocardiac crises .

Prevention of thyrocardiac crisis and a coma consists in adequate therapy by tpreostatiche-sky pharmaceuticals. A strumectomy (see the Craw diffusion toxic), thyroidectomy (see), the subtotal resection of the goitrous changed thyroid gland needs to be made only after achievement by the patient of the euthyroid (compensated) state.

Complications, treatment of T., directed to normalization of content of thyroid hormones in blood, and the forecast — see the Craw diffusion toxic., complications, treatment, forecast; Hypophysis, pathology.

Thyrotoxicosis of newborns. In most cases T. it is found in the children who were born from the women suffering from T. or having it in the anamnesis. In families of sick children the frequency of diseases of a thyroid gland is much higher, than in families of healthy children.

In a pathogeny of T. at newborns a certain part is assigned it is long to the operating thyroid stimulator (long acting thyreoid stimulator — LATS) and other tireoidstimuliruyushchy antibodies (TSA), to-rye often are defined in blood of mother and child and can be passed through a placental barrier, and also a tiroliberina, to-ry it is capable to pass through a placenta and, besides, it is excreted with breast milk.

T. at newborns, as a rule, has tranzitorny character and passes through 6 — 12 weeks after the birth. However sometimes T. does not disappear and proceeds many years, being followed typical a wedge, a picture of a diffusion toxic craw (see. Craw diffusion toxic ). Tranzitorny forms T. note at boys more often.

Children with T. in most cases are born premature, a characteristic external sign is the convex speaker a forehead. At most of children note the goitrous changed thyroid gland. Body temperature is increased. A bad increase of body weight against the background of the increased appetite, vomiting and diarrhea, perspiration, excitability, concern, emergence of the increased gloss of eyes are specific, exophthalmos (see). Tachycardia, a gepatosplenomegaliya, jaundice, thrombocytopenia, a tachypnea, expansion of borders of heart, arrhythmia, hypostases and a hyperplasia of an adenoid tissue are possible. Rentgenol. the research of a skeleton reveals the accelerated development of bone system (see. Age bone ), craniostenosis (see).

The hormonal profile is characterized by substantial increase of content of thyroid hormones in blood at very low concentration of thyritropic hormone (see) or its total absence. Often reveal existence in blood of mother and the child of LATS and TSA.

In the prenatal period the diagnosis of T. it can be put on the basis of hypermotility of a fruit, tachycardia, detection of LATS and TSA in blood of mother and a fruit irrespective of a functional condition of a thyroid gland of mother.

During the carrying out to lay down. actions anti-thyroid means are appointed depending on weight of T. at the newborn: solution of Lugol (1 drop each 8 — 24 hours before improvement of a state, a cut, as a rule, comes on 2 — the 3rd week of life), mercazolil (metpmazol; 0,5 — 1 mg on 1 kg of weight a day). Appoint also Obsidanum (2 mg to 1 kg of weight a day), carry out a symptomatic treatment — administration of isotonic solution of sodium chloride, cordial glycosides, glucocorticoids, etc.

Prevention of T. at newborns consists in identification of risk group (pregnant women with T. and the diseases of a thyroid gland which even are not followed by T., with the adverse genealogical anamnesis — diseases of a thyroid gland at relatives, especially with autoimmune defeats of tissue of thyroid gland and hyperfunction of gland), in strict observance of terms of observation and inspection of pregnant women in clinics for women for the purpose of prenatal diagnosis of T. at a fruit, in early diagnosis and timely treatment of T. at pregnant women.

Bibliography: Golber L. M. and To and N-d r about r V. I. Thyrocardiac heart, M., 1972, bibliogr.; About ER of JI. M, etc. A pathogeny of motive frustration at a thyrotoxicosis, M., 1980, bibliogr.; The guide to clinical endocrinology, under the editorship of V. G. Baranov, page 348, L., 1977; Glories and N and L. S. Heart at endocrine diseases, M., 1979; Dane man D. Ho ward N. J. Neonatal thyrotoxicosis, J. Pediat., v. 97, p. 257, 1980; Ober-disse K., Klein E. u. Rei n-wei n D. Die Krankheiten der Schild-driise, Stuttgart — N. Y., 1980; Petersen S. S e r u p J. Neonatal thyrotoxicosis, Acta paediat. scand., v. 66, p. 639, 1977; Sil vestro L. Bona G. Moderne acquisizioni sulla tireotossicosi neonatale, Minerva pediat., v. 32, p. 741, 1980; Sing e r J. Neonatal thyrotoxicosis, J. Pediat., v. 91, p. 749, 1977; Textbook of endocrinology, ed. by R. H. Williams, p. 117, Philadelphia a. o., 1981.

M. I. Balabolkin; L. S. Slavina (cards.), M. F. Logachev (ped).