If you have mild
aortic valve regurgitation, you will probably not even
notice it. However, over a period of several years, the condition tends to get
worse. As it gets worse, it can cause other diseases (complications) to
develop. The most common complications are
heart failure, irregular heartbeats (arrhythmias), and
infection in the heart (endocarditis). A major focus of
treatment for aortic valve regurgitation will be preventing these
complications.
Heart failure
Heart failure is one of the most common complications of aortic
valve regurgitation. It involves a loss of heart function that progressively
worsens and can lead to death. If you have chronic regurgitation, your heart is
able for a while to compensate for the extra blood leaking back into the left
ventricle and prevent it from affecting your other organs. However, over a long
period of time-from several months to several decades-your heart will
weaken.
Heart failure caused by regurgitation occurs when the heart becomes
so weakened that it can no longer deliver all of the blood the body needs. The
heart serves as a pump in the body, moving all of the blood through the
circulatory system. When the pump begins to fail, blood is not moved through
the body properly, depriving organs of the oxygen and nutrients they need to
function correctly. Because it causes damage to the left ventricle, aortic
valve regurgitation causes left-sided heart failure.
If you develop heart failure from aortic valve regurgitation, you
will likely experience shortness of breath, the most common symptom of
left-sided heart failure. You may have difficulty catching your breath because,
as your heart begins to fail, blood begins to back up in your lungs. Fluid in
the lungs reduces the space available for oxygen exchange to take place,
causing you to feel as though you cannot get enough air into your lungs.
Irregular heartbeats (arrhythmias)
The heart is a muscle that contracts to pump blood out and relaxes
to allow blood back in. A network of nerves covers the surface of the heart.
When these nerves fire (send an electrical signal), they cause your heart to
contract. A collection of cells on the right atrium, called the sinoatrial
node, controls this web of nerves. As it fires, so do the rest of the nerves,
causing all of the muscle cells in the heart to contract together, producing
one forceful pump. The electrical activity of the heart starts in the atrium
and travels through another collection of cells called the atrioventricular
(AV) node to reach the ventricles.
As aortic valve regurgitation stretches the heart muscle, it can
also disrupt this web of nerves. Communication pathways may weaken and not
deliver the signal from the sinoatrial node effectively. Because the AV node is
close to the aortic valve, the stretching and scarring caused by aortic valve
regurgitation can damage the AV node.
- Damage to the AV node may cause a slowed
heartbeat (bradyarrhythmia) or a more serious condition called heart block.
Heart block refers to an abnormality in the conduction of electricity through
the normal electrical pathways of the heart. The abnormality "blocks" the
electrical impulse from continuing through the normal electrical pathways and
usually results in a slower heart rate. If you have bradyarrhythmia or heart
block, you may feel faint, dizzy, lightheaded, and short of breath and have
chest pain, fatigue, and
palpitations; you may also be confused or have
difficulty concentrating and increased difficulty exercising. A slow heart rate
can sometimes be treated with medications, but in many cases a pacemaker is
surgically implanted to help the heart beat at a normal rate. Treatment of
heart block usually requires a pacemaker.
- Stretching and
enlargement of the atria (the heart's upper chambers) may also result in an
irregular heartbeat, such
atrial fibrillation. Symptoms of atrial fibrillation
may include weakness, shortness of breath, and heart palpitations or more
serious problems such as fainting (syncope).
The irregular beats prevent the blood from flowing smoothly through
the heart; this allows clots to form. If these clots break loose, they can
travel to your brain and cause a
stroke.
Infection in the heart
If your heart has already been weakened by valve problems,
infection can further worsen its function. Bacteria also may be able to eat a
hole through the valve, further worsening the regurgitation. If the bacteria
clump in the bloodstream, they can cause problems with circulation, and even
cause strokes. An infection in your heart can be a life-threatening matter that
needs immediate treatment.
Infections in the heart (endocarditis) can cause and be caused by
aortic valve regurgitation. Endocarditis is considered a complication of
regurgitation when regurgitation causes it. An infection in the heart is caused
by bacteria that have set up residence in the heart or on a valve by attaching
to the wall of the heart or valve. The small imperfections in valves create a
convenient nest for the bacteria to settle, which is why a valve problem places
you at increased risk for infection.
Your heart and blood vessels are structured so that bacteria have
a difficult time attaching and creating an infection. The surfaces of the
insides of the heart and blood vessels are smooth and uniform, giving bacteria
little chance to gain a foothold on which to grow. However, when the structure
of your valve is altered, the smooth lining is also altered.
Once bacteria begin to grow and reproduce, they have access to all
the food they need from the sugar (glucose) in your blood. The bacteria will
likely grow rapidly, often so fast that your body's immune system cannot keep
the infection in check.
Bacteria clump together, becoming a larger mass attached to the
heart muscle or valve. These clumps are called vegetations, and as they become
larger, pieces are likely to break off. The pieces act much like a blood clot.
They can block your arteries, causing heart attacks and stroke. They also can
spread the infection throughout your body by traveling through your
bloodstream.
