Pulmonary arterio-venous fistula.

As would be expected, the lesion is recognized in young to early middle life. The patient tends to be frail rather than robust, though there are exceptions to this, and there is no physical retardation. Clubbing of the fingers is frequently present, and telangiectases or hemangiomata may be present in the skin or mucous membranes. The most common presenting symptoms are cyanosis, which sometimes dates from soon after birth, and dyspncea; both tend to be progressive. Attacks of faintness, convulsions, or vertigo may be complained of, and epistaxis or hemoptysis is common. Headache, cough, or venous thrombosis may be encountered. The heart and blood pressure are within normal limits, and the circulation time is unaltered or slightly increased. Changes in the blood depend on the size of the shunt, but there is usually polycyth2emia, increased blood volume, and diminished oxygen saturation. Cardiograms may show slight right axis deviation. The lungs may be apparently normal unless the aneurysm is superficial and large, when a murmur may be heard over it. This is a very valuable sign occurring in about half the cases. The vital capacity is normal. Commonly the X-ray will show an irregular shadow, sometimes pulsatile; tomography or angiography yields valuable additional data. If the fistula is at the pulmonary bases, it may not be easily defined radiologically, as the cupola of the diaphragm or the heart shadow can obscure it. It should not be forgotten that there may be multiple fistule present. The differential diagnosis lies between cyanotic congenital cardiac disease, polycythmemia rubra vera, bronchiectasis, and pulmonary tuberculosis. Treatment, if indicated, is surgical, pneumonectomy or lobectomy being the operation of choice.