The vast majority of people have a left-sided heart, and a small percentage have a right-sided heart. A right-sided heart can be seen, and is not rare, and a left-sided heart is about 2/3 on the left side of the chest cavity and 1/3 on the right side of the chest cavity. There is a concept that needs to be corrected. Although the heart is divided into four chambers, left atrium, left ventricle, right atrium, and right ventricle, do not take it for granted that the left ventricle and left atrium are on the left side of the body and the right atrium and right ventricle are on the right side of the body. The entire heart is the size of my fist, with 2/3 of it on the left side of the chest cavity and 1/3 on the right side. The right edge of the heart which is the right side of this part is the right atrium, most of the front, shallow surface is the right ventricle and right atrium, and a small part is the left ventricle and left atrium, the left ventricle is mainly on the diaphragm surface, especially when doing heart examination, most of the electrodes or contacts of cardiac ultrasound and electrocardiogram are on the left side.