Factors affecting resolution of pericardial effusions in primary hypothyroidism: a clinical, biochemical and echocardiographic study

Abstract

Summary Echocardiography detected pericardial effusions in five out of six consecutive untreated patients with severe primary hypothyroidism and suspected myopathy, whereas the chest X-ray suggested only one. During L-thyroxine replacement, serial echocardiograms detected decrease in the size of the effusions in all the patients. This occurred before the serum thyroid stimulating hormone (TSH) levels had significantly changed, although there was a small but significant rise in serum thyroxine. In one patient complete resolution of the effusion occurred before the patient became euthyroid, a previously unreported finding. Small voltage complexes, T-wave inversion and non-specific T-wave flattening were the commonest electrocardiographic abnormalities noted. The former invariably and the latter two abnormalities frequently, reverted to normal before the patient became biochemically and clinically euthyroid. T-wave inversion in a particular lead, however, did not invariably do so, suggesting that permanent structural change might possibly have occurred. The plasma creatine kinase (CK) was raised in four patients, and markedly raised at levels usually associated with muscular dystrophy, in two. At the onset of resolution of the pericardial effusions, the total plasma CK had fallen significantly in all patients in whom it was raised.

Thyroid Disease and the Heart

“…It is well recognized that patients with hypothyroidism can develop a protein-rich pericardial and/or pleural effusion. 10,101 Most, if not all, of the changes in cardiac structure and function associated with hypothyroidism are responsive to T 4 replacement. 28,101 The treatment of hypothyroidism in the setting of known or suspected cardiac disease poses some challenges.…”

“…10,101 Most, if not all, of the changes in cardiac structure and function associated with hypothyroidism are responsive to T 4 replacement. 28,101 The treatment of hypothyroidism in the setting of known or suspected cardiac disease poses some challenges. In young, otherwise healthy patients with overt hypothyroidism, treatment with a full replacement dose of L-thyroxine (Levoxyl, Synthroid) of Ϸ1.6 g/kg per d can be initiated at the outset.…”

A rare case of massive pericardial effusion secondary to hypothyroidism

“…Finally, once the diagnosis has been established, treatment with thyroid replacement hormones usually leads to the resolution of the effusion over 2-12 months without sequelae (15).…”

Triiodothyronine induces over-expression of alpha-smooth muscle actin, restricts myofibrillar expansion and is permissive for the action of basic fibroblast growth factor and insulin-like growth factor I in adult rat cardiomyocytes.

“…On the other hand, thyroid hormone deficiency is associated with decreased contractility and with cardiac dilation (4,5). Both types of changes can be reversed by redressing the unbalanced thyroid hormone status (6,7).…”