1. Before doing anything, check for scars - a midline sternotomy scar without a corresponding vein graft scar on the legs suggests a valve replacement (AVR has a flow murmur with a loud 2HS)
2. In Blalock-Taussig shunts - there is usually a midline scar + L/R posterior thoracotomy scar
3. Whereas in complete repair of VSD the only sign may be pulm regurg/stenosis
1. In 3rd CN palsy, check with cover test to exclude lazy eye.
4 causes with scars (pneumonectomy, thoracoplasty, lobectomy, lung transplant)
4 causes without scars (effusion, fibrosis, bronchiectasis, COPD)