Thyroid hormone plays a vital
role in regulating
human metabolism. They
affect the functions of major organs, such as the
brain,
liver,
skeletal muscle, and
heart.
Hypothyroidism can
lead to
dilated cardiomyopathy and decreased
heart function. In this
report, we describe a case of a teenage boy
who developed
dilated cardiomyopathy due to
hypothyroidism and was considered to undergo
heart transplantation. Levothyroxine monotherapy was initiated but produced no improvement. Thereafter, a combination
therapy of
liothyronine and levothyroxine was administered, and
heart function was gradually restored; he recovered completely after 6 months.
Cardiac myocytes respond more specifically to
liothyronine than to levothyroxine. Therefore, we suggest that
liothyronine and levothyroxine combination
therapy should be considered rather than levothyroxine monotherapy for
hypothyroidism accompanied by
heart disease.