Frederic G. Dalldorf

Myxedema coma during long-term amiodarone therapy

Amiodarone is a potent new antiarrhythmic drug that has multiple effects on thyroid function, including inhibition of extrathyroidal triiodothyronine production and rarely, iodine-induced hypothyroidism. This report describes a man with recurrent ventricular tachycardia in whom hypothyroidism developed during amiodarone therapy and who died of probable myxedema coma. Parenteral and oral thyroxine therapy promptly reduced serum thyroid-stimulating hormone concentrations without increasing the patients very low serum triiodothyronine concentration. This response to thyroxine suggests that thyroxine itself may have biologic activity and participate directly in regulation of thyrotropin secretion. Because amiodarone-induced hypothyroidism may be life-threatening, thyroid function should be monitored before and during amiodarone therapy, and the drug discontinued or appropriate therapy instituted if hypothyroidism develops.

Case Report: Splenic Infarction and Acute Splenic Sequestration in Adults with Hemoglobin SC Disease

While acute splenic sequestration and splenic infarction are commonly observed in infants and young children with sickle cell anemia, they are rarely experienced by adult hemoglobin S homozygotes because the recurrent splenic infarction that takes place during childhood is typically followed by scarring, atrophy, and splenic fibrosis. Both acute splenic sequestration and splenic infarction do remain relatively common in adults with the other sickle hemoglobinopathies. These episodes are almost certainly a consequence of the persistently enlarged and distensible spleens that often remain present in these conditions. In this report, the authors describe two adult patients with hemoglobin SC disease: one who developed acute splenic sequestration and one with splenic infarction. In neither case was there a history of recent air travel or exposure to altitude. The clinical course of these two syndromes is presented, and the hematologic, radiologic, and pathologic manifestations are discussed. Because they can sometimes be difficult to distinguish from one another, and because a failure to identify acute splenic sequestration can be catastrophic, these two entities must be included in the differential diagnosis for any hemoglobin SC patient who present with an unexplained fall in hemoglobin, left upper quadrant pain, unexplained fever, or symptomatic splenomegaly.

Premature closure of the foramen ovale and hypoplasia of the left heart

Although premature closure of the foramen ovale has been proposed as a possible cause of hypoplastic left heart syndrome, very few such cases have been described. We have seen two examples of the combination and no associated malformations. In both the foramen was firmly closed on its left atrial aspect and the dimensions of the left sided structures were well below normal values.

Arteriosclerotic Vascular Disease and Testicular Fibrosis

The autopsy protocols and sections of the testes were examined in a group of 199 men over the age of 35 years who were free of known causes of either vascular disease or testicular fibrosis. In 44 (22 per cent) of the cases, testicular sections showed marked fibrosis of the peritubular membranes or complete hyalinization. Testes of the remaining men showed minimal or no signs of testicular fibrosis. Of these 155 patients with normal or minimally fibrotic testes, 47 (30.7 per cent) had complications of arteriosclerotic vascular disease (i.e., myocardial or cerebral infarcts, arteriosclerotic aneurysms, etc.) and in 36 cases (23.5 per cent) those complications were considered to be the cause of death. Of the 44 cases with advanced testicular fibrosis, four (9.1 per cent) had complications of arteriosclerotic vascular disease and only one patient (2.2 per cent) died of the disease. An interpretation of these findings is presented.