This defect consists of having both atrio-ventricular and ventriculo-arterial connections. Note that neither hypertrophic cardiomyopathy nor interrupted aortic arch are considered here.
Left ventricular outflow tract obstruction (LVOTO) can occur at several levels:
Left ventricular outflow tract obstruction (LVOTO) can occur at several levels:
- Supravalvar LVOTO seldom occurs in isolation: it is usually part of Williams syndrome.
- Valvar LVOTO in the adult patient with congenital heart disease is usually due to bicuspid aortic valve. Bicuspid aortic valve is the most common congenital cardiac anomaly occurring in 1-2% of the population with males affected 4 times more frequently than females. It usually occurs in isolation but is associated with other abnormalities in 20% of the cases, the most common being coarctation of the aorta and PDA.
- Subvalvar LVOTO is usually a ridge partially or completely encircling the left ventricular outflow tract or a long narrowing beneath the base of the aortic valve. Occasionally, there is a tunnel-like narrowing of the whole left ventricular outflow tract with a small aortic root. This type of defect affects males twice as often as females. Family members may be affected. Rarely, abnormal insertion of the mitral valve or accessory mitral leaflet may cause significant obstruction.