Heart failure is the most serious
complication and the leading cause of death from
mitral valve stenosis.
In mitral valve
stenosis, the valve opening narrows, and the heart initially compensates by
pumping harder. But eventually pressure builds in your left atrium as more and
more force is needed to push blood across your narrowing mitral valve. This
eventually stretches the atrium's walls, weakens the heart, and leads to heart
failure.
A narrowed mitral valve may also not close properly and
the valve may begin to leak, causing
mitral valve regurgitation. The stenosis and
regurgitation also causes pressure to build up in the lungs (pulmonary
hypertension), which can lead to the pulmonic valve leaking (pulmonic
regurgitation). When pulmonary hypertension occurs, it may lead to right-sided
heart failure.
As fluid gathers within the heart and lungs, the
heart must exert even greater force to pump blood to the body—further weakening
the heart and causing even more fluid buildup—thereby creating a vicious cycle.
Eventually the heart loses its ability to pump, resulting in heart failure and
often death.