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 anemia, 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 breath.
What is it?
How does it cause high-output heart failure?
|Severe anemia||Blood contains too few oxygen-carrying red blood cells.||Requires the heart to pump more blood each minute to deliver enough oxygen to the tissues of the body|
|Hyperthyroidism||Thyroid gland produces too much thyroid hormone.||Increases the body's overall metabolism, thus increasing the demand for blood flow|
|Arteriovenous fistula||An abnormal connection between an artery and a vein||Short-circuits the circulation and forces the heart to pump more blood overall to deliver the usual amount of blood to the vital organs|
Deficiency of thiamine (vitamin B1)
|Leads to increased metabolic demand and increased need for blood flow|
|Paget's disease||Abnormal breakdown and regrowth of bones, which develop an excessive amount of blood vessels||Increased number of blood vessels requires increased cardiac output.|