Journal of Pediatric Cardiology and Cardiac Surgery

A six-year-old boy was admitted to our institute because of syncope and exercise intolerance. Cardiac catheterization revealed elevated pulmonary arterial pressure of 89/35(65) mmHg and elevated pulmonary vascular resistance index of 14.4 Woods units·m². We diagnosed severe primary pulmonary hypertension with right heart failure. Since no effective therapy for pulmonary hypertension was established then, we could not treat him effectively. However, his trans-tricuspid pressure gradient on echocardiogram gradually decreased without therapy and he became asymptomatic when he reached junior high school. He did not visit our outpatient clinic after he started college because of commitments at work. When admitted to our hospital at the age of 28, cardiac catheterization showed that his pulmonary arterial pressure and pulmonary vascular resistance index had decreased to 50/18(32) mmHg and 7.8 Woods units·m², respectively. He had frequent nasal bleeding and we found one telangiectasia spot on his foot. His genetic analysis revealed an ALK-1 mutation and he was diagnosed with heritable pulmonary arterial hypertension. Pediatric heritable pulmonary arterial hypertension with ALK-1 mutation is usually progressive and has poor prognosis. However, this may not be always true, as demonstrated by our case.