Expansion
Right border is right atrium; left border is aortic knuckle, pulmonary trunk, left atrial appendage and left ventricle
Expansion
Right border, from top down:
- Superior vena cava
- Right atrium
- (Sometimes a sliver of inferior vena cava at the cardiophrenic angle)
Left border, from top down:
- Aortic knuckle
- Pulmonary trunk
- Left atrial appendage
- Left ventricle
The left atrium sits posteriorly and normally contributes only its appendage to the outline; when it enlarges it produces a double right heart border, splaying of the carina and posterior displacement of the oesophagus.