Tetralogy of Fallot is a rare condition caused by a combination of four heart defects that are present at birth. These defects affect the structure of the heart, cause oxygen-poor blood to flow out of the heart and into the rest of the body. The four defects are
Ventricular septal defect (hole between the right and left ventricles)
Narrowing of the pulmonary outflow tract (the valve and artery that connect the heart with the lungs)
Overriding aorta (the artery that carries oxygen-rich blood to the body) that is shifted over the right ventricle and ventricular septal defect, instead of coming out only from the left ventricle
Thickened wall of the right ventricle (right ventricular hypertrophy)
Common sysmptoms of this condition are
Weakness
Fainting
Shortness of breath
Cyanosis