Chapter 43

    Characterized by hypoplasia of certain anatomyinical structures of the left heart, where the left ventricle, left atrium, mitral or aortic orifice and aortic arch will present a different varying degree of underdevelopment.
    The main congenital pathologies responsible for this syndrome are:

1. Atresia or interruption of the aortic arch
2. Hypoplasia of the aortic arch
3. Atresia of the mitral valve
4. Atresia of the aortic valve

    It is important to recognize that the atresia or underdevelopment of any of this structures course associated to the hypoplasia of the other left sided structures in most of the cases, which gives to this entity many times a common clinical and psysio-pathological condition, which explains the reason of this special agrupation of, what otherwise, are different pathologies.
    In this regard, for example, the commonest type of mitral atresia is the one, associated to aortic atresia which may have a clinical presentation similar to isolated atresia of the aortic valve.
    The patient with pure aortic atresia otherwise, will most of the time have a marked atrophy of the mitral valve structures, and as in the previous case, the clinical picture will depend upon the significance of the left to right communication and the degree of pulmonary hypertension.
    In all of these entities, the great arteries are normally located and the main anatomical feature is given by a significant atrophy or hypoplasia from the left mitral valve through the aortic arch.
    For an accurate evaluation of any of the previous congenitals, angiography and left sided catheterization are essential.