Introduction Hypertrophic Cardiomyopathy is a genetic disorder, relatively common, with widely variable clinical presentation. The disease can be recognised in all age groups and has an unpredictable prognosis, especially in those without symptoms.

The purpose of this presentation is to bring to your attention the curious case of a toddler with Hypertrophic Cardiomyopathy with high elevation of muscular enzymes and liver enzymes that can not be explained by his cardiac condition alone.

CASE REPORT We present the case of a two and a half year-old male toddler, diagnosed with Hypertrophic Obstructive Cardiomyopathy at 10 months, who associates Atrial Septal Defect, Mitral Regurgitation and elevated liver and muscular serum enzymes. The clinical presentation is poor in signs and symptoms, with discrete pallor and relatively good effort tolerance.

The patient was admitted in hospital several times for the investigation of the elevated serum enzymes, but all attempts to link this paraclinical abnormality to an etiological diagnosis failed: negative genetic tests for Duchenne Muscular Dystrophy and Type II Glycogen Storage Disease – Pompe Disease, negative for haematological disease – thalassemia and also negative serology for viruses with liver tropism.

ConclutionS Particular aspect lies in the discrepancy between serious muscle cytolysis syndrome and clinical paucisimptomatic presentation. Is severe muscle cytolysis explained only by heart condition?