A very rare birth defect where the aorta and the pulmonary artery both exit from the right ventricle and thus blood is unable to be pumped to the lungs. However, a hole connects the two ventricles and ultimately allows some blood flow to the lungs. In the type I the hole is located just below the aorta and there is no narrowing of the pulmonary valve. See also Double outlet - right ventricle I
