Biscupid valves (or mitral valve) is present between left atrium and left ventricle. Normally it prevents backflow of blood to left atrium when left ventricle contracts. Damaged valves can't close properly so when the LV undergoes systole then some blood backflow into LA and this decreases the amount of blood being pumped into systemic circulation (to aorta).
If you found this answer helpful then please rate it. Comment if you have any problems in understanding this answer.
Get Answers For Free
Most questions answered within 1 hours.