When I first described the symptomatology of the myxedema heart 40 years ago1 it was considered a rare variety of cardiac pathology. The myxedema heart is no longer a rarity. The increased rate of its reported incidence must be attributed to the great therapeutic advances made in the last decades in the field of thyroid disease, especially thyroid hyperfunction, such as antithyroid drugs and the clinical use of radioiodine.
The symptom complex of myxedema heart includes bradycardia, an often enormous dilation of the heart shadow, superficial heart contractions, a low cardiac output, flat or absent T waves with occasional lengthening of the Q-T interval in the electrocardiogram (ECG), soft heart sounds with correspondingly low waves in the phonocardiogram, and an abnormal venous pulse curve (absence of the auricular wave, a hump on the limb of the curve corresponding to ventricular systole, and complete absence of the normal diastolic fall).