肺高血圧症を伴った甲状腺機能亢進症による二次性心筋症の1例

A case of secondary cardiomyopathy with pulmonary hypertension due to hyperthyroidism

　甲状腺機能亢進症において循環器系の障害が出現することは周知のとおりである。今回我々は，肺高血圧症を伴った甲状腺機能亢進症による二次性心筋症の1例を経験した。甲状腺心^1）の心筋生検像および肺筒血圧症に関する報告は少なく，興味ある症例と考えられたためここに報告する。

A case of thyrotoxic heart disease with pulmonary hypertension was reported. The patient, 52 year-old retired professional bicycle athelete, first noticed hypersweating and hand tremor at the age of twen-ties. Since 6 months before admission to our hospi-tal, he had complained leg edema and exertional dyspnea. On admission, electrocardiogram (ECG) re-vealed atrial fibrillation and chest X-ray film showed the dilatation of ventricles. The cardiac catheteriza-tion before the treatment revealed pulmonary hy-pertension and the increase in cardiac output. The left ventriculogram showed increase in the left ven-tricular end-diastolic volume and severely reduced wall motion. The specimens obtained from percu-taneous left ventricular endomyocardial biopsies demonstrated irregular hypertrophy of myocardial fibers, myocardial fiber degeneration and slightly diffuse fibrosis of interstitium with infiltration of inflammatory cells and edema. Thus, the clinical diagnosis of secondary cardiomyopathy with pulmo-nary hypertension due to hyperthyroidism was made. The right heart catheterization after the treatment of thiamazole showed an improvement of pulmonary hypertension and a normalization of stroke volume. Incidentally, ECG revealed the conversion from atrial fibrillation to normal sinus rhythm. The thy-rotoxic heart disease complicated with pulmonary hypertension contrary to the lack of systemic hyper-tension is a rare case. Although the precise mecha-nism of pulmonary hypertension of this patient was not clear, the slight organic change in the pulmo-nary vasculature due to hyperdynamic state for about 30 years and the exercise load for the pro-fessional bicycle athelete was considered to be an important factor.