Apathetic Hyperthyroidism Presenting as Tricuspid Regurgitation

¹ Department of Medicine and the C. V. Richardson Laboratory the University of North Carolina, Chapel Hill

Apathetic hyperthyroidism, as its name implies, presents itself in an insidious manner so that the diagnosis may be obscure until a near-terminal situation. Such was the situation in two elderly women manifesting lethargy, muscular weakness, and anasarca associated with severe tricuspid regurgitation. Both had been unresponsive to the usual medical regimen consisting of digitalis and diuretics for congestive failure until they were discovered to be thyrotoxic. Appropriate treatment and a return to a euthyroid state resulted in remarkable subjective improvement as well as disappearance of signs of congestive failure and tricuspid regurgitation. The possible mechanisms whereby thyrotoxicosis could lead to predominantly right-sided failure are discussed.