日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

Secondary cardiomyopathy related to a systemic disorder should be ruled out when diagnosing idiopathic cardiomyopathy. Nutrient deficiency is a known cause of secondary cardiomyopathy. Herein, we report a case of secondary cardiomyopathy caused by carnitine deficiency with short bowel syndrome. A 6-year-old girl receiving total parenteral nutrition for short bowel syndrome manifested cold symptoms for 5 days that resulted in orthopnea, thereby prompting hospitalization. Chest radiography showed a cardiothoracic ratio of 60％, and echocardiography revealed fraction shortening of 17％. Her operated bowel was bleeding, causing chronic anemia, obtaining a hemoglobin level of 6.7 g/dL. Cardiac function was not improved by blood transfusion and milrinone therapy but improved in merely 3 days by L-carnitine administration. The free carnitine level was found to be low after treatment (17.8 µmol/L); therefore, she was diagnosed with secondary cardiomyopathy caused by carnitine deficiency. In conclusion, carnitine deficiency can cause secondary cardiomyopathy; hence, the serum carnitine level of patients at risk should be examined periodically. Furthermore, the risk of cardiomyopathy must be considered in patients with increased cardiac load, including anemia and infection. Thus, early administration of L-carnitine is necessary for secondary cardiomyopathy caused by carnitine deficiency.