A positive heart foam test suggests an abnormal passage between the atria. Commonly, abnormal shunting of blood at the atrial level due to an unclosed foramen ovale results in a portion of the blood flow flowing directly into the left atrium via the right atrium without gas exchange in the lungs. Normally, blood flows from the right atrium into the right ventricle, enters the pulmonary circulation, and flows into the left atrium, and this portion of blood flow does not undergo gas exchange in the lungs and therefore has insufficient blood oxygenation. Due to the presence of an abnormal channel due to the unclosed foramen ovale, there are also patients who can lead to the development of cerebral embolism.