The heart pumps blood to send vital oxygen throughout the body. It’s a maze of four chambers: two on the left and two on the right. Blood enters the heart at the upper right chamber, which is called the right atrium. It’s pumped into the lower chamber, known as the right ventricle, which then sends blood into the lungs for oxygenation. The now oxygen-rich blood returns to the heart through the left atrium and moves to the left ventricle...