II. Causes: Increased pulmonary vasculature (edematous, white lung fields)
- Cyanotic heart disease (mixed oxygenated and deoxygenated blood)
- Noncyanotic heart disease (right-to-left shunt)
III. Causes: Decreased pulmonary vasculature (clear or black lung fields)
- Cyanotic heart disease
- Noncyanotic heart disease (left-sided obstruction)
- Aortic Stenosis
- Pulmonary stenosis
- Aortic Coarctation
IV. Causes: Classic heart appearances on xray
-
Tetralogy of Fallot
- Boot-shaped heart
-
Total Anomalous Pulmonary Venous Return (TAPVR)
- Snowman or Figure-of-eight sign
- Transposition of Great Vessels
- Egg on a string sign
-
Aortic Coarctation
- Three sign (aortic knob prominent, with distal aortic dilitation)
V. Causes: Normal heart size despite Congenital Heart Disease
- Tricuspid atresia
- Pulmonary atresia
- Pulmonic stenosis
- Tetralogy of Fallot
VI. Calculation: Cardiothoracic Index
- Calculates whether heart diameter is more than half (roughly) the chest cavity width
- Measurements
- Transverse diameter of the heart on AP Chest XRay
- Thoracic cavity width on AP Chest XRay
- Calculation
- Index = (heart diameter) / (thoracic width)
- Interpretation
- Index >0.6 is consistent with cardiomegaly
VII. References
- Civitarese and Crane (2016) Crit Dec Emerg Med 30(1): 14-23
- Fuchs and Yamamoto (2012) APLS, Jones and Bartlett, Burlington, 135-7