多发性肌炎病人心肌受累已有报道,但毕竟为少见合并症。作者报告1例发生于肌痛和肌无力4年以后的病人。病者男性,37岁,1973年两大腿开始发生疼痛和强直。继而出现右膝关节渗出。入院时检查两大腿明显萎缩。类风湿性关节炎乳胶试验、抗链“O”效价、华氏反应和性病血清试验、血沉、血清钙和磷、碱性磷酸酶、蛋白电泳和甲状腺扫描均为阴性,脊椎和两膝的 X 线检查亦为阴性。接着发现肌酸酐激酶增加为644mIU/L(正常<50mIU/L),和肌肉活组织检查显示肌纤维有灶性坏死和再生,伴有斑点样间质慢性炎症浸润。这些表现与多发性肌炎一致,使用了强的松龙治疗,开始每天100mg,以后减为每天20mg维持。4年间缓解和复发交替出现需临时增加皮质类甾醇剂量。肌酸酐激酶仍保持在644～5,400mIU/L Myocardial involvement in patients with polymyositis has been reported, but after all, a rare complication. The authors report a patient who developed after 4 years of myalgia and muscle weakness. Male, 37 years old, 1973 Two thighs began to develop pain and stiffness. Then appear right knee exudate. Check the two thighs were significantly reduced when admitted to hospital. Rheumatoid arthritis latex test, anti-chain “O” titer, Fahrenheit test and STD serum test, ESR, serum calcium and phosphorus, alkaline phosphatase, protein electrophoresis and thyroid scan were negative, spine and knee X Line inspection is also negative. The creatinine kinase was then found to increase to 644 mIU / L (normal <50 mIU / L), and muscle biopsy revealed focal necrosis and regeneration of the muscle fibers with infiltration of chronic interstitial inflammatory infiltrates. These manifestations are consistent with polymyositis, using prednisolone therapy starting at 100 mg daily and later reduced to 20 mg daily. In 4 years, relapse between remission and relapse need temporary increase of corticosteroid dose. Creatinine kinase remained at 644-5,400mIU / L