We have had several questions recently about edema of the lower extremities
in patients with congestive heart failure. Lymphedema causes swelling of
the affected extremity; however, not all swollen extremities are caused by
lymphedema. In congestive heart failure the heart does not work as well as
it should. Think of the heart as a pump with an inlet and an outlet. When
a pump does not work as well as it should, the amount of fluid pumped out by
the pump is decreased. In addition to this, the amount of fluid that the
pump is trying to remove remains high.
Congestive heart failure is very similar. In congestive heart failure, the
amount of blood pumped out by the heart is less than normal, decreasing the
total amount of oxygen available to the tissues. Patients with congestive
heart failure become easily fatigued because the heart cannot pump enough
blood to satisfy the oxygen requirements during periods of exercise. Since
the output from the heart is low, the input into the heart from the veins
is also diminished and blood builds up behind the heart much like water builds
up behind a dam.
As blood builds up waiting to get into the heart, the pressure in the veins
increases. The veins are permeable and the increased pressure causes fluid
to leak out of the veins and into the tissue. This results in the edema
commonly seen in patients with heart failure. The edema is frequently seen
in the ankles and lower legs since this is the area of greatest pressure.
The swelling can be reduced by simply raising the legs to the level of the
heart. That is why doctors recommend that patients keep their legs
elevated while sitting. Keeping the legs elevated reduces the pressure on the heart
and veins and allows the fluid to return to the vascular system. Since
patients cannot spend all their time with their legs raised, compression
stockings are used to apply a counter pressure and keep the edema to a
minimum. Many patients benefit from additional compression and use the
ReidSleeve while they are sitting or lying down. Your doctor will be able to
help distinguish lymphedema from swelling due to congestive heart failure.
In addition to congestive heart failure, other conditions can lead to
swelling that can be mistaken for lymphedema. Some of these conditions can
be serious and should be evaluated by a doctor. Swelling in the head and
neck area can look like lymphedema; however, it may be due to compression
of the superior vena cava, the large vessel that returns blood from the head
to the heart. This is called superior vena cava syndrome and can be a serious
problem that requires the attention of a physician. Compression should not
be used in when a patient has superior vena cava syndrome. A proper
diagnosis should be made and the cause of the problem should be treated.
Tony Reid MD Ph.D