The valves in your heart prevent blood from flowing in the wrong direction through your heart (backwards).
If your valves don't work properly, they don't close (leading to leaking of blood) and/or open completely (making them too narrow) during each heartbeat. Your heart has to work harder to keep enough blood moving in the correct direction. This additional workload can become too much for your heart and heart failure develops.
|How abnormal heart valves can cause heart failure|