What causes pulmonary artery dilation?

There are many potential causes of pulmonary artery dilation, including:

1. Pulmonary hypertension: This is a condition in which the pressure in the pulmonary arteries is abnormally high. It can be caused by a variety of factors, including chronic lung diseases, heart diseases, and genetic disorders.

2. Congenital heart defects: Certain congenital heart defects, such as ventricular septal defect (VSD) and atrial septal defect (ASD), can cause increased blood flow to the lungs, which can lead to pulmonary artery dilation.

3. Eisenmenger syndrome: This is a rare condition that occurs when a person has a large VSD and develops pulmonary hypertension. The increased pressure in the pulmonary arteries can cause them to dilate.

4. Aortic stenosis: This is a condition in which the aortic valve is narrowed, which restricts blood flow from the heart to the body. The increased pressure in the heart can cause the pulmonary arteries to dilate.

5. Pregnancy: The hormonal changes that occur during pregnancy can cause the pulmonary arteries to dilate. This is usually a temporary condition that resolves after pregnancy.

6. Other medical conditions: Certain other medical conditions, such as scleroderma, lupus, and rheumatoid arthritis, can cause pulmonary artery dilation.

7. Idiopathic: In some cases, pulmonary artery dilation can occur for no apparent reason. This is known as idiopathic pulmonary artery dilation.