About
Heart Failure
Heart
failure is a serious condition in which the heart fails to pump
blood effectively. This causes the blood flow to decrease to muscles,
tissues, and organs throughout the body. It also causes blood
to back up into the veins that return blood to the heart. The
pumping efficiency of the heart may be weakened by a heart attack,
by diseases affecting the heart muscle, by mechanical problems
with the heart valves, by prolonged high blood pressure, or by
abuse of drugs or alcohol.
Heart
failure is the leading diagnosis and cause of death due to heart
disease in recent years, with about 3 million Americans (1% of
the U.S. population) affected. It is the number one reason for
hospitalization admissions in people over age 65.
However,
the good news is that more people are learning how to reverse
heart failure with an aggressive cardiorespiratory rehabilitation
program including exercise, dietary changes, medications, and
other lifestyle changes. In this section, you'll learn about the
latest medical findings and where to get more information about
heart failure.
Information
for this section taken from: Mayo Clinic Family Health Book, William
Morrow and Company, Inc., 1990; K. Weber et al., "Exercise
Testing in the Evaluation of Cardiopulmonary Disease," Clinics
in Chest Medicine 5 (March 1984); Journal of the American College
of Cardiology 1996;27:345-52; Success with Heart Failure: Help
and Hope for Those with Congestive Heart Failure, Marc A. Silver,
M.D., Insight Books (a division of Plenum Publishing Corporation),
233 Spring Street, New York, NY 10013-1578, 1994.
Signs
and symptoms of heart failure
- Swollen
ankles; if bedridden, swelling in lower portions of the back
- Shortness
of breath (during activities and/or shortly after lying down
in bed at night)
- Weakness
and fatigue
- Chest
pains
- Weight
gain or loss
- Changes
in appetite
- Inability
to shake a cold or other minor illness
Diagnosing
heart failure
Heart
failure causes a feeling of weakness and fatigue. Routine physical
activities such as climbing stairs become difficult to perform.
A person with heart failure will also have trouble breathing after
exerting themselves such as when exercising. In advanced stages,
a person will feel short of breath when lying down in bed. You
will need to elevate your head on several pillows to sleep comfortably.
If
you have early warning signs of heart failure such as shortness
of breath and fatigue, talk to your doctor. He or she may give
you a number of diagnostic tests including a test for ejection
fraction (the amount of blood the heart ejects or pumps with each
contraction) and a test for oxygen consumption (how the heart
and lungs work together to provide blood and oxygen to your body).
Because
one of the key symptoms of heart failure is exercise intolerance,
a cardiopulmonary exercise test gives the most useful information
about how the heart, lungs, blood vessels and muscles work are
working together. In this test, you will take a standard exercise
test while breathing through a mouthpiece that measures your breath
during exercise. The system's computer will simplify this information
into a value called VO2max representing your body's oxygen consumption
at maximal exercise. You can compare your value to the following
chart:
| VO2max
(ml/min/kg) |
Functional
Class |
Performance
Comparison |
Normal
range(1)
60-80
40-59
30-39
21-29
|
A |
Elite
Well-Trained
Conditioned
De-Conditioned
Training Program Recommended
|
16-20
|
B |
Mild
to Moderate
Cardiopulmonary Disease
May need rehabilitation and medical therapy; may be early
for surgery |
10-15
|
C |
Moderate
to Severe
Cardiopulmonary Disease
Potential surgery candidate (2) |
6-9
|
D |
Severe
Cardiopulmonary Disease
Surgery candidate (2) |
<6
|
E |
Critical
Cardiopulmonary Disease
Significant risk for surgery (2) |
(1)
- Normal range values decline with age, are lower for women than
men, and are lower when testing is performed on a cycle instead
of a treadmill
(2) - Assuming that underlying disease has surgical implications
Therapy
Exercise
Although
people with heart failure need lots of rest, this does not mean
you should spend all day in bed. While restricting activity may
reduce burden on the heart, it also produces a severe deconditioning
of the heart and other muscles. Many heart failure experts are
now commonly encouraging their patients to embark on an aggressive
cardiac rehabilitation training program.
Your
doctor may give you an individualized exercise program which,
when combined with medication, has helped many patients get better
without surgery. Do not begin an exercise program without first
talking to your doctor.
For
more information about exercise and the American College of Sports
Medicine's guidelines for exercise, click here to reach "All
About Exercise".
Diet
- Restrict
salt intake
- Avoid
alcoholic beverages
- Reach
and maintain a weight appropriate for your height and build
Medication
Heart
failure is often treated with drugs in combination with exercise
and other lifestyle changes. Common medications are diuretics;
digoxin; and angiotension-converting enzyme inhibitors, or ACE
inhibitors.
Diuretics,
sometimes called water pills, are also used to treat mild cases
of high blood pressure. They increase the rate your body eliminates
urine and salt, thereby decreasing the load on your lungs and
the swelling in your legs. In addition to salt loss, potassium
is also eliminated, so your doctor will monitor your blood potassium
level and prescribe a supplement if necessary.
Digoxin
increases the strength of the heart's pumping, and is especially
useful if your heart failure is caused by a systolic heart rhythm
problem.
The
newest form of drug therapy for heart failure, ACE inhibitors,
also called vasodilators, dilate arteries to reduce the work the
heart has to do and thereby allowing it to pump blood more effectively.
Surgery
Surgical
treatment for heart failure is the exception rather than the rule.
However, some cases of heart failure require surgery. For example,
you may require surgical repair of damaged heart tissue or a heart
valve replacement. For people with myocarditis or cardiomyopathy,
heart transplantation may be an option.
The
American College of Cardiology (ACC) recommends that all patients
being considered for heart transplantation go through their recommended
evaluation, which includes an exercise stress test with oxygen
consumption (VO2max). The ACC's guidelines are as follows*:
I.
Accepted Indications for Transplantation
1.
Maximal VO2 < 10 ml/kg per min with achievement of anaerobic
metabolism (the point at which the body has reached maximal
aerobic capacity and can no longer perform work aerobically)
2.
Severe ischemia (chest pain) consistently limiting routine activity
not amenable to bypass surgery or angioplasty
3.
Recurrent symptomatic ventricular arrhythmias refractory to
all accepted therapeutic modalities
II.
Probable Indications for Cardiac Transplantation
1.
Maximal VO2 <14 ml/kg per min and major limitation of the
patient's daily activities
2.
Recurrent unstable ischemia not amenable to bypass surgery or
angioplasty
3.
Instability of fluid balance/renal function not due to patient
noncompliance with regimen of weight monitoring, flexible use
of diuretic drugs and salt restriction
III.
Inadequate Indications for Transplantation
1.
Ejection fraction <20%
2.
History of functional class III or IV symptoms of heart failure
3.
Previous ventricular arrhythmias
4.
Maximal VO2 >15 m/kg per min without other indications
*
JACC Vol. 22, No. 1, July 1993: 27.
As
you can see, peak oxygen uptake (VO2max) <14 ml/kg per min
is used as the primary indicator of whether a person needs a heart
transplant. However, peak oxygen uptake is affected by a person's
age, gender, and weight. More recently, doctors at the Saint Louis
University School of Medicine published findings that if heart
failure patients achieve greater than 50% of their predicted VO2max
they can safely defer transplantation (JACC, 1996; 27:345-52).
Your doctor will rely on a number of published charts showing
predicted values based on a person's age, weight, and gender.
