Question: My cardiologist performed a bubble study with a full echocardiogram. Would I use separate codes for the bubble study and echocardiogram? New York Subscriber Answer: No. CPT® does not offer codes specific to the bubble study. You would report a regular echocardiogram code, and here are some possibilities to choose from (others are possible): Echocardiograms use high-frequency sound waves to create images of the heart. The cardiologist then uses the images to evaluate the heart's structure to see how well it is functioning. An echocardiogram with a bubble study (bubble echocardiogram) is actually the same procedure as an echocardiogram, but it does provide additional information. With a bubble echocardiogram, the healthcare provider places an IV in the patient's arm, and agitated saline with bubbles is injected into the vein. This enables the cardiologist to see if there is a tiny hole between the upper chambers of the heart - a patent foramen ovale (PFO) or an atrial septal defect (ASD).