Clinical analysis of dilated cardiomyopathy with fatty acid oxidation disorders in nine children

Objectives To study the clinical manifestations, diagnosis and treatment of dilated cardiomyopathy with abnormal fatty acid metabolism in children. Methods The clinical manifestations, laboratory examinations, treatment and follow-up evaluation of children identified as dilated cardiomyopathy with abnormal fatty acid metabolism at Beijing Anzhen Hospital from January 2007 to June 2011 were retrospectively reviewed. Results Nine children were enrolled, including 5 males and 4 females, onset age ranging from 11 months to 18 years, course of disease from 0.5 to 4.5 years. Nine cases were all fatigued with one or more symptoms as muscle weakness (4 cases), limb proximal muscle atrophy (1 case), seizures (2 cases) and growth retardation (2 cases). Nine cases were all found with varying degrees of hepatomegaly accompanied by liver dysfunction (8 cases), elevated CK, CK-MB, increased lactate dehydrogenase (LDH) (7 cases), elevated lactic acid( 6 cases), hypoglycemia ( 2 cases), high blood ammonia ( 3 cases). Increased left ventricular end-diastolic diameter and decreased ejection fraction were measured by echocardiography in cases. Two cases showed myogenic damage by electromyography. Tandem mass spectrometry examination revealed that free carnitine was significantly higher in 1 case, normal in 3 cases while decreased in 5 cases; acylcarnitine increased in 7 cases, decreased in 1 case, normal in 1 case. The primary clinical diagnosis was carnitine palmitoyltransferase Ⅰ deficiency in 1 patient, systemic carnitine deficiency in 1 patient, multiple acyl-CoA dehydrogenase deficiency in 4 patients, long-chain acyl-CoA dehydrogenase deficiency in 3 patients. Based on conventional treatment of heart failure to all patients, supplement of L-carnitine and vitamin, dietary guidance including low-fat and preventing from starvation achieved better clinical, biochemical, cardiac imaging and function improvement. Conclusions Metabolic screening should be performed in children with cardiomyopathy suspectedly secondary to fatty acid oxidation disorder. This may help define early diagnosis, therapeutic strategy and improve the prognosis.