Chapter 37

    This occurs when a coronary artery which arises normally from the aorta communicates directly with one of the cardiac chambers, with a coronary sinus or with a pulmonary artery.
    The main hemodynamic consequence of the problem is progressive left to right shunt.
    The most frequently involved artery is the right coronary communicating with the right ventricle.
    The findings and symptomatology of the problem will depend on the volume of the shunt. Most of these infants do not show symptomatology during the first few years, then the fistula increases in size and volume and results in a large left ventricular volume overload and finally congestive heart failure.
    The most typical findings are:

1. Loud and continuous murmur in the right or left parasternal area. If the artery connects with one of the ventricles, the diastolic portion of the murmur will be more intense.
2. Corrigan's pause (wide pulse).
       The ECG will be normal in early infancy and then will show signs of left ventricular diastolic overload.    The chest x-ray is not too diagnostic and will show a progressive enlargement of the left ventricle. Otherwise it may be normal. Signs of congestive failure will be seen in terminal stages.    The cardiac catheterization will show the left to right shunt, and the final diagnosis will be made by the selective coronary angiography which visualizes the shunt.