As in the normal human heart, there exists two mitral valve leaflets, each with its own set of chordae. Unique to the parachute mitral valve is that the chordae insert on one papillary muscle, rather than two distinct papillary muscles. Often, the chordae are short and thick and this combination of factors leads to restricted movement of the mitral valve leaflets and obstruction of blood flow into the left ventricle. The supramitral ring is a connective tissue ring at the base of the atrial surfaces of the mitral valve leaflets. They may protrude into the orifice of the mitral valve, leading to fixed obstruction of blood flow from the left atria to the left ventricles. Subaortic stenosis has been observed in both muscular and membranous forms. In either case, a variable degree of obstruction may be observed at the ventricular surface of the aortic valve. This presents an obstruction of flow of blood from the ventricle to the aorta. Coarctation of the aorta which is, narrowing of a section of the aorta may also be observed. Again this presents an obstruction to blood flow out from the left ventricle. Since there is obstruction of flow into and out of the left ventricle, the prognosis depends on the degree of obstruction and its effect on blood flow.
Shone's syndrome
Frey's syndrome
Wilkinson's syndrome
Brown's syndrome
Weaver syndrome
Horner's syndrome
Winter-over syndrome
Nance–Horan syndrome