Pulmonary Hypertension with a High-Output Hemodynamic Profile in a Child with MELAS: A Case Report.

Pulmonary hypertension (PH) is uncommon in myopathy, encephalopathy, lactic acidosis, and stroke-like (MELAS) and its hemodynamics are poorly described. A 2-year-old Japanese girl was referred to our hospital with PH diagnosed during pneumonia treatment. Cardiac catheterization revealed PH with a high cardiac output. The patient was diagnosed with MELAS based on multiorgan involvement and the detection of an m.3243A>G mutation. PH therapy was partially effective, and oxygen supplementation may help improve PH without worsening the high cardiac output.