Now, however, even though we have a tiny bit of blood going into the right atrium, there is still enough blood inside the left atrium to actually go into the left ventricle and eventually pump to the tissues and organs and systems of the body. So normally, this is not a big problem. However, what it can cause is an embolism. So what can happen is the blood inside the right atrium. If the heart is actually undergoing some type of rigorous activity, so the person, let's say, running, and the heart has to pump more, then what can happen is the pressure inside the right atrium can be slightly greater than inside the left atrium. And so some of that blood in the right atrium can move into the left atrium and then directly into the left ventricle and into the systemic circulatory system.