High-output heart failure happens when the
body's need for blood is unusually high, so heart failure symptoms happen even though the heart is working well.
This type of heart failure happens to a very small number of people with heart failure.
What happens to the heart?
High-output heart failure occurs when the normally functioning heart
cannot keep up with an unusually high demand for blood to one or
more organs in the body. The heart may be working well
otherwise, but it cannot pump out enough blood to keep up with
this extra need.
What causes it?
There are a variety of conditions that can
significantly increase the body's need for blood and oxygen, resulting in
high-output heart failure. These conditions include
hyperthyroidism, and pregnancy. Although the causes of
high-output heart failure are different from the cause of other types of heart
failure, the end result is the same: Your heart isn't supplying enough blood
to meet your body's needs. High-output heart failure results in the same symptoms of heart failure, including fatigue and shortness of
Causes of high-output heart failure
What is it?
How does it cause high-output heart failure?
Blood contains too few oxygen-carrying red blood
Requires the heart to pump more blood each minute to
deliver enough oxygen to the tissues of the body
Thyroid gland produces too much thyroid hormone.
Increases the body's overall metabolism, thus
increasing the demand for blood flow
An abnormal connection between an artery and a
Short-circuits the circulation and forces the heart
to pump more blood overall to deliver the usual amount of blood to the vital
Deficiency of thiamine (vitamin B1)
Leads to increased metabolic demand and increased
need for blood flow
Abnormal breakdown and regrowth of bones, which
develop an excessive amount of blood vessels
Increased number of blood vessels requires increased