Intracranial arteriovenous fistulas in infancy--haemodynamic considerations.

The clinical, electrocardiographic and radiological features and cardiac catheterization findings in 3 young infants with large intracranial arteriovenous fistulas are presented. In addition to the congestive cardiac failure, the haemodynamic disturbances which give rise to central cyanosis, pulmonary hypertension and, in some instances, poor peripheral pulses, are discussed. The cyanosis in these children may have been the result of a combination of right-to-left shunting at atrial or ductal level, as well as intrapulmonary shunting in association with pulmonary engorgement. Left ventricular dysfunction, with elevated end-diastolic pressures, appeared to be most marked in those cases in which poor peripheral pulses were present. Increased pulmonary arterial pressures (considerably greater than systemic arterial pressure in 2 of the cases) are considered to be due to a combination of the obligatory left-to-right shunt which results from the fistula, and to the super-added effect of altitude (1765 metres) with resultant pulmonary vasoconstriction.