Aorto-pulmonary Window (AP Window) is a very form of congenital heart defect (CHD), meaning by present at birth.

In AP window, there is a hole between two great vessels of the heart, one is known as ascending aorta (that carries pure blood to the whole body) and another is pulmonary artery (which carries impure blood to the lungs).

Due to this hole, there is shunting of blood from aorta to pulmonary artery with high pressure that can lead to overflow of blood to the lungs & can leads to signs and symptoms of heart failure as well as of pulmonary hypertension.

AP window can be an isolated anomaly or it can be associated with other form of heart defects at birth which can be either coarctation of the aorta, interrupted aortic arch, ventricular septal defect, tetralogy of fallot or atrial septal defect etc.

Types of AP window

            There are 4 types of AP window.

Most common type is Type 1 and is most commonly amenable for transcatheter closure of AP window. Type 3 is associated with other cardiac defects.

Symptoms due to AP window

Symptoms due to AP window depend mainly on size of defect as well as weight and age of the child.

If size of AP window or hole is large and is an isolated lesion, then it can leads to heart failure and child presents with difficulty in breathing, excess sweating during feeding, poor weight gain, suck-rest-suck cycle, pneumonia like situation, frequent hospital admissions, etc. Symptoms are generally presented in first 1-2 months of age.

With small AP window, child is generally not having symptoms but detected on routing examination by a pediatrician by hearing murmur of AP window in children.

In moderate size of AP window, symptoms are generally same as mentioned in large PDA but in less intensity.

If moderate to large sized AP window is not treated on time then it can results in an irreversible state and can leads to bluish discolouration of lips and fingers (cyanosis) along with shortness of breath, known as Eisenmenger Complex.