**5. Ayanotic heart defects: Left-to-right shunts**

When there is a defect in the partition between left and right heart structures, the oxygenated blood is shunted from left-to-right because of generally lower pressure and/or resistance in the right heart than in the left. The physical findings are either a manifestation of flow across the defects or due to effects of excessive flow across the cardiac chambers (volume overload) and valves. The magnitude of the shunt determines the clinical presentation and symptoms.
