心筋炎におけるタリウム心筋シンチグラム像の検討

Clinical evaluation of Tallium-201 myocardial schltigram in Myocarditis

　心筋炎において，急性の経過をたどり，炎症の消退と共に，良好な経過を示す症例がある反面，重篤な不整脈，難治性の心不全により，予後不良となり，死に至る症例もある^1〜3）。

　心筋炎の診断は，一般に，その発症経過，心電図所見，血清心筋逸脱酵素，さらに，ウイルス性心筋炎においては，ウイルス抗体価の，上昇をもってなされ，最終的には，心内膜下心筋生検による，病理学的診断が重要である。一方，本症において，治療および予後判定のうえで，障害された心筋の性状ならびに，心機能を知ることは重要である。

In fourteen cases of prior Myocarditis, thallium-201 myocardial scintigraphy was performed and myocardial perfusion was compared with left ventricular function assessed by technetium-99m gated blood pool scan and echocardiogram.

Ten cases (Group I) demonstrated poor thallium uptake in left ventricular myocardium or focal thallium perfusion defects.

On the other hand, four cases (Group II) showed normal perfusion. In five cases of Group I, left ventri-cular enlargement was prominent mimicking dilated cardiomyopathy, the mean and standard deviation of left ventricular ejection fraction (LVEF) was 32±6%.

In two cases of Group I, poor thallium uptake in left ventricular myocardium and a focal thallium perfu-sion defect demonstrated in acute phase were resumed in chronic phase in accordance with the improvement of clinical manifestation and biochemical examination.

Thallium myocardial scintigraphy was useful in Myo-carditis not only to evaluate the extend of myocardial damage in acute phase but also to follow up in chronic phase.