What does the cardiac load mean?

Cardiac preload refers to the load borne by the heart during systole, and cardiac afterload refers to the load borne by the heart during diastole.

Cardiac preload mainly refers to the volume load, that is, the volume of blood before entering the heart. Clinically, the left ventricular end-diastolic pressure is usually used as an index to measure preload. Water and sodium retention, hyperthyroidism and other reasons can cause cardiac preload to increase. Cardiac afterload refers to the load after systole, generally refers to pressure load, which is the pressure received when blood is ejected from the heart. Hypertension, aortic stenosis and other diseases can cause cardiac afterload to increase.