Myxedema Heart

Abstract

The term “myxedema heart” was first employed by Zondek¹ in 1918 to describe a syndrome due to myxedema and consisting of enlargement of the heart, sluggish cardiac movements, electrocardiographic changes, and congestive myocardial failure. Although Zondek’s observations have been fully confirmed, it has been well established also that myxedema only rarely is complicated by congestive heart failure. En largement of the heart and changes in the electrocardiogram occur commonly, however, and the term myxedema heart has now come to be applied to these changes even though evidence of congestive failure is absent. Organic heart disease may also be present, and because of this, the cardiac abnormalities in any case of myxedema must be shown to be amenable to therapy with thyroid substance before one can conclude that they were due to myxedema heart.

The present report is based on eight cases of myxedema in which electrocardiograms were made at the time the condition was first diagnosed (table 1). In two of the cases the symptoms had developed three months and nine years, respectively, after thyroidectomy, while in the other six, the condition was of spontaneous origin. The age of the patients ranged from 37 years to 68 years. Five were women and three were men. The initial basal metabolic rates ranged between —24 percent and —41 percent, and the plasma cholesterol concentrations between 196 mgm. per 100 cc. and 248 mgm. per 100 cc. The resting pulse rate ranged from 48 to 78 beats per minute, the systolic blood pressure. . .