[Cyanosis for more than 4 years in a girl aged 4 years and 3 months]

A girl, aged 4 years and 3 months, presented with cyanosis of the lips shortly after birth. She then experienced shortness of breath after activity 1 year ago and acrocyanosis 3 months ago, with obvious acropachy and toe deformity. Laboratory examinations revealed an increase in hemoglobin (178 g/L) and a reduction in arterial partial pressure of oxygen (37.7 mm Hg). Plain and contrast-enhanced CT scans of the lungs showed a large area of dense shadow and multiple nodules with clear boundaries in the right lower lung, as well as thickening of the arteries and dilatation of the veins in the right lower lung. Magnetic resonance angiography of the pulmonary artery showed large arteriovenous malformation in the lung. The child was diagnosed with congenital pulmonary arteriovenous fistula and was given interventional embolization of the pulmonary arterial fistula. The child was followed up at 3 months after surgery. The symptoms of shortness of breath and cyanosis disappeared, and activity tolerance, heart rate, hemoglobin, red blood cell count, and transcutaneous oxygen saturation all returned to normal.