What precisely is Mitral Insufficiency?

Mitral valve insufficiency, mitral insufficiency or MI is a disorder of one of the heart valves, the mitral valve. The heart valves regulate the flow of blood through the four chambers of the heart. Each valve consists of a delicate, but stable tissue structure. When blood flows through the four heart chambers, the valves open and close and thus ensure that the blood flows in the correct direction.

The mitral valve is located between the left atrium and the left ventricle and works as a seal: it ensures that the blood flows forward through the heart with a normal heartbeat. If the mitral valve does not close completely, blood flows back in the opposite direction, or back into the atrium. We call this backflow mitral insufficiency.

Various stages of leaking mitral heart valve

The New York Heart Association (NYHA) classifies the degree of severity of a leaking mitral valve on the basis of physical capacity.

NYHA stage I
Heart condition known, but no limitation on physical capacity. 

NYHA stage II
Slight limitation on physical capacity, no symptoms at rest, symptoms with everyday physical exertion.

NYHA stage III

Physical capacity is considerably reduced, symptoms arise with slight physical exertion, but no symptoms at rest as yet.

NYHA stage IV
Symptoms with all physical exertion and also at rest, bedridden.