A bubble study is done in conjunction with an echocardiogram. A “contrast” material is used during the test to get better pictures of the heart. One type of contrast is saline (sterile salt water). During a bubble study the nurse will shake the salt water until it forms small bubbles. The bubbles are then injected into the vein through an intravenous line (IV).
In a normal heart the bubbles are filtered by the lungs and are seen only on the right side of the heart. If the bubbles are seen on the left side, it shows that there is an opening between the two sides of the heart. This abnormality can be an atrial-septal defect or a ventricular septal defect. The bubble study helps to identify these abnormalities. The study itself is very simple and safe and it usually only adds a few minutes to the test.