In a patient with an ASD and a pulmonary shunt, how many beats are typically needed to see contrast on the left side?

In the case of a patient with an atrial septal defect (ASD) and a pulmonary shunt, the typical time required to see contrast on the left side is 1-2 beats. This rapid passage of contrast occurs due to the direct connection between the right and left atria created by the ASD. When contrast is injected into the right atrium, it can quickly flow across the defect into the left atrium, leading to early visualization of contrast in the left side.

The swift movement of blood and contrast through the ASD means that once injected, it can pass into the left side of the heart almost immediately, resulting in detection within just a couple of cardiac cycles. This is a critical aspect of the hemodynamics involved in ASDs and highlights the efficiency with which contrast can move from the right to the left heart in this specific anatomical situation.