Atrial septal defect in a dog: the value of Doppler echocardiography.

A four-month-old German Shepherd Dog was presented with an atrial septal defect. An estimated pulmonary to systemic blood flow ratio in the range of 2,5 to 2,9:1 was determined by means of Doppler echocardiography. This technique allows for the non-invasive determination of the Qp:Qs ratio by calculating aortic versus pulmonary artery cardiac output or by determining mean trans-atrial septal velocities. In addition, the flow patterns across the valves are characterised and the direction of the shunt determined. Atrial septal defect is reviewed with special reference to the value of Doppler echocardiography.