Until recently "thyroid heart" was considered to be a definite entity and was admitted without discussion as a member of the group of organic cardiac diseases. This idea is now losing popularity, and the tendency to consider so-called thyroid heart as a simple functional disorder is becoming more and more prevalent.
The fundamental reasons for this change are based on experimental proof—pathologico-anatomic, electrocardiographic and roentgenographic, though none of these has been capable of showing definitely the existence of a constant specific alteration in the heart in hyperthyroidism. Thus, Takane1 and Boyksen2 have found infiltration or degenerative changes in the hearts of rats intoxicated with thyroid preparations, whereas Goodpasture3 found only slight alterations in rabbits under similar conditions, but he admitted that there might exist an increased liability of the myocardium to infection. Rake and McEachern4 said they considered that the lesions they observed were of no
GOTTA H. SIZE AND SHAPE OF THE HEART IN HYPERTHYROIDISMA TELEROENTGENOGRAPHIC STUDY OF TWO HUNDRED CASES. Arch Intern Med (Chic). 1938;61(6):860–874. doi:10.1001/archinte.1938.00180110015003