Chapter 38

    The most common is the left coronary artery arising from the Pulmonary artery. (Bland-White-Garland Syndrome)
    These patients will usually show, a few days after birth, signs of heart failure, respiratory tract infections, tachypnea, irritability, pallor and diaphoresis in relation with possible angina pectoris due to the relative ischemia of the area irrigated by the left coronary artery. With time collateral circulation develops, and a more or less significant left to right shunt appears between the right and the left coronary artery circulations, determining, the presence of a loud continuous murmur typically located at the left lower sternal border. Signs of mitral incompetence are also frequent, due to ischemia of the papillary muscles supporting the mitral valve and endocardiac fibroelastosis.
    The ECG usually shows signs of antero-lateral ischemia and even signs of anterolateral infarction.
    The chest x-ray will show a normal cardiac silhouette, but with time,left ventricular hypertrophy will be present.
    In time, these patients present with a left to right coronary arteriovenous fistula with left ventricular volume overload and relative ischemia of the same ventricle which determines the early symptomatology noted in these patients (retrograde direction of the blood flow through the left coronary artery, from abnormal communications with the right coronary which arises normally from the aorta). The medical management of these patients attempts control of the congestive heart failure, and anginal attacks and treatment of the respiratory tract infections.
    Surgical correction of the abnormal origin of the left coronary is ideal and should be considered depending on the patient's clincial picture and symptomatology at different ages.
    At times if good collateral circulation develops between the right and left coronary artery system, total ligation of the left coronary may be considered. However, if this collateral circulation is not large enough, the final results may produce a large antero-lateral infarction and, in most cases, patient death. Abnormal origin of the right coronary artery from the pulmonary artery, is a very rare situation and essentially will present with the same symptoms and findings than the previous case. However, both the symptomatology and the physical findings will be less significant.
    The abnormal origin of both coronary arteries from the pulmonary is almost always accompanied by the patient's death a few hours or a few days after birth.
    Ectopic origin of the left anterior descending artery from the right coronary sinus was described, simulating at times total occlusion of L.A.D. in coronary angiography. Left coronary passing posterior to the pulmonary artery is another unusual situation.
    A pathology where the left anterior descending arises from the right coronary system is Tetralogy of Fal lot, in which the artery crosses the outflow tract of the right ventricle and may eventually create a problem during surgical correction of the malformation.
    Communications between one of the coronaries and a right sided extructure originate a left to right shunt with arterialization of the pulmonary artery blood. Less usual is the communication with left ventricle or left atrium which do not cause any alteration in the systemic arterial oxygenation but produce often diastolic regurgitation through the abnormal shunt giving rise to a hemodynamic state similar to aortic insufficiency.

Left coronary artery abnormally originates from the pulmonary artery trunk. There is left to right shunt, which develops aat the coronary artery level via multiple collaterals between the right and left coronary arteries.