What term describes the backward flow of blood through a defective heart valve?

Regurgitation refers to the backward flow of blood through a defective heart valve. In a healthy heart, valves function to ensure unidirectional flow of blood; they open to allow blood to move forward and close tightly to prevent backflow. When a valve becomes defective, it may not close properly, resulting in some of the blood flowing back into the chamber it just left instead of progressing to the next chamber or vessel. This can lead to various complications within the cardiovascular system.

Stenosis pertains to the narrowing of a valve opening, which restricts blood flow but does not involve backflow, making it unrelated to the concept of regurgitation. Ischemia is a term used for inadequate blood supply to an organ or tissue, often leading to damage or dysfunction, and does not directly pertain to valve malfunction. Thrombosis refers to the formation of a blood clot inside a blood vessel and is not specifically related to the functioning of heart valves. Therefore, regurgitation is the correct term for the backward flow of blood due to a defective valve.