Aortopulmonary Window
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# Overview
Aortopulmonary window was first described by Elliotson as a defect which causes communication between proximal aorta and main pulmonary artery.There are different ways of classifying aortopulmonary window. proximal defects are the most common between proximal aorta and sinus of valsalva. Aortopulmonary (APW)  window is a rare condition with presence of a communication between the ascending aorta and pulmonary artery with two separate semilunar valves.The cause of APW has not been identified Aortopulmonary Window must be differentiated from other diseases or conditions that cause continuous heart murmur. Manifestation of the disease is not specific, but majority of patients have a large left to right shunt.If left untreated, large APW may cause symptoms of pulmonary hypertension and congestive heart failure such as tachypnea, diaphoresis, failure to thrive and recurrent respiratory difficulties.The diagnosis of aortopulmonary window is made by echocardigraphy after suspicion of large left to right shunt. Gold standard foe diagnosis of aortopulmonary window is echocardiography. If echocardiography does not reveal enough information, a CT scan can be performed. Main treatment for AP window is surgery.

# Historical Perspective
Aortopulmonary window first described by Elliotson as a defect which causes communication between proximal aorta and main pulmonary artery. 

# Classification
There are different ways of classifying aortopulmonary window. proximal defects are the most common between proximal aorta and sinus of valsalva. Distal types are located in the upper portion of the ascending before the aortic branches. Total defects are large and involve the majority of the ascending aorta between valsalva and aortic branches.

# Pathophysiology
- Aortopulmonary (APW)  window is a rare condition with presence of a communication between the ascending aorta and pulmonary artery with two separate semilunar valves.
- APW can present as an isolated phenomena but more over is assosiated with other congenital heart defects such as interrupted aortic arch, transposition of the great arteries and tetralogy of fallot.

# Causes
- The cause of APW has not been identified.
- It may be associated with some genetic disease such as DiGeorge syndrome(choromosome 22q11 deletion)

# Differentiating Aortopulmonary Window from other Diseases
Aortopulmonary Window must be differentiated from other diseases or conditions that cause continuous heart murmur. for further information click Here.

# Epidemiology and Demographics
- Since APW is a very rare congenital heart defect, there is very little known about epidemiology of the disease.

# Risk Factors
There are no established risk factors for aortopulmonary window.

# Screening
There is insufficient evidence to recommend routine screening for aortopulmonary window.

# Natural History, Complications, and Prognosis
- Clinical features of APW have been described differently due to their classification.
- Manifestation of the disease is not specific, but majority of patients have a large left to right shunt.
- patients with small defects may be asymptomatic.
- If left untreated, large APW may cause symptoms of pulmonary hypertension and congestive heart failure such as tachypnea, diaphoresis, failure to thrive and recurrent respiratory difficulties.
- pericardium is often hyperdynamic and a mitral valve rumble, causes continues heart murmur.
- Bounding pulses happen due to decreased diastolic blood pressure secondary to aortic flow reversal in diastole.
- If the diagnosis is not made until late in infancy or during childhood. APW may lead to eisenmenger syndrome.

# Diagnosis

## Diagnostic Study of Choice
The diagnosis of aortopulmonary window is made by echocardigraphy after suspicion of large left to right shunt. 

## History and Symptoms
- tachypnea
- diaphoresis
- failure to thrive
- recurrent respiratory difficulties

## Physical Examination
- continuous murmur
- If late eisenmenger's syndrome:
cyanosis
clubbing
- cyanosis
- clubbing

## Laboratory Findings
There are no specific diagnostic laboratory findings associated with aortopulmonary window..

## Electrocardiogram
- Tachycardia
- Increased right and left sided voltage

## X-ray
- Cardiomegaly
- Increased pulmonary vascular markings

## Echocardiography or Ultrasound
- Gold standard foe diagnosis of aortopulmonary window.
- Since the connection is usually without significant restriction, color-Doppler echocardiography will not demonstrate high velocity jet.

## CT scan
- If echocardiography does not reveal enough information, a CT scan can be performed.
- CT scan can potentially delineate the aortopulmonary connection.

## MRI
- Quantitive analysis of flow in 4D MRI can help to distinguish the severity and siz of aortopulmonary window.

## Other Imaging Findings
There are no other imaging findings associated with aortopuklmonary window.

## Other Diagnostic Studies
There are no other diagnostic studies associated with aortopulmonary window.

# Treatment

## Medical Therapy
- Main treatment for AP window is surgery.
- Anticongestive medications
Diuretics(furosemide and chlorothiazide)
digoxin
- Diuretics(furosemide and chlorothiazide)
- digoxin
- ACE inhibitors and ARB
- Medical therapy should be approached with caution, since there can be abnormal renal perfusion.

## Surgery
- Surgery is the mainstay of treatment for aortopulmonary window.
- Surgery must be considered at the time of diagnosis as the size of defect has not still grown, in order to decrease risk of developing pulmonary hypertension.
- Surgery involves seperation of the great arteries with either suture division or patch closure of aorta and pulmonary artery.
- Catheterization can be considered when defect is small.

## Primary Prevention
- There are no established measures for the primary prevention of aortopulmonary window.

## Secondary Prevention
- There are no established measures for the secondary prevention of aortopulmonary window.