What Is High Output Heart Failure?

High output heart failure is a rare condition that occurs when the heart pumps blood normally or at a higher volume than usual but cannot keep up with the body’s demands.

Heart failure is usually caused by the heart’s inability to pump enough blood to the body’s organs to keep them functioning. This inability is caused by a heart that can’t fill with enough blood or a heart that is too weak to pump properly.

In high output heart failure, however, the heart functions normally, but it does not pump enough blood to meet the body’s needs.

Though “heart failure” sounds scary, it does not mean that your heart has suddenly stopped. However, it is a serious condition that requires treatment.

While there is no cure for heart failure, treatments such as healthy lifestyle changes, medications, and/or procedures can improve and extend your quality of life.

Types of High Output Heart Failure

High output heart failure can be broken down into three main types: metabolic, myocardial, and mechanical vascular.

Metabolic

The metabolic process of the body has three purposes: to convert food to energy; to convert food to the building blocks for proteins, fats, and carbohydrates; and to eliminate waste.

With metabolic high output heart failure, the body’s metabolic demands are increased, placing strain on the heart.

Hyperthyroidism and certain blood cancers can lead to a high heart rate, low blood pressure, and increased metabolism.

In metabolic high output heart failure, the heart continues to function, but it is not able to pump enough blood to keep up with the metabolic demands of the body.

Myocardial

Myocardial refers to the heart. In high output heart failure that is myocardial in nature, the heart tissue itself is directly or indirectly affected by a disease or infection affecting the whole body.

• Hyperthyroidism: An increase in thyroid hormones and metabolic changes can affect the tissue of the heart itself.
• Sepsis: An extreme reaction of the body to an infection that causes widespread inflammation, this can cause a variety of changes to the heart and blood volume. People with sepsis usually present with a low blood volume, and in later phases of sepsis there can be a reduction in the heart’s function.
• Chronic lung disease: This can cause a drop in oxygen in the blood, which causes the heart to pump more blood that does not meet the demands of the body.

Mechanical Vascular

Mechanical vascular high output heart failure involves changes to the vascular system, including the arteries, veins, and capillaries.

Arteriovenous fistulas (AVFs), which can be present at birth or acquired, can cause an artery to bypass a vein, leading to an increased blood flow to the heart. This can cause a higher heart rate and larger volume of blood to be pumped into the body, which leads to high output heart failure.

Liver cirrhosis affects heart rate response and could lead to the bypassing of arteries and veins.

Though the exact mechanism for how obesity causes high output heart failure is not fully understood, it is known to be associated with excessive dilation of the blood vessels, which causes low blood pressure throughout the body, leading to a lack of nutrients to the body’s organs.

High Output Heart Failure Symptoms

Common symptoms for high output heart failure are similar to the symptoms of other types of heart failure. These include but are not limited to:

• Shortness of breath
• Fatigue or weakness
• Swelling of the hands, feet, or abdomen
• A lasting cough
• Nausea
• Weight gain
• Needing to urinate more often
• Dizziness
• Confusion

Causes

High output heart failure is caused by either an uptick in the body’s demand for blood from increased metabolism or an increase in blood flow with no resistance in the veins that causes low blood pressure.

Most often, high output heart failure is caused by another medical condition. The most common causes include:

• Obesity
• Anemia
• Pregnancy
• Liver disease
• Arteriovenous shunts
• Lung disease
• Myeloproliferative disorders, or rare blood cancers

Diagnosis

To diagnose high output heart failure, your healthcare provider will take a medical history, complete a physical exam, and run various tests. You may also be referred to a cardiologist.

During the exam, your healthcare provider will measure your weight, blood pressure, and heart rate. They will listen to your heart and lungs to check for abnormalities.

Your healthcare provider may also administer diagnostic tests, such as:

• Echocardiogram
• Cardiac CT scan
• Cardiac MRI
• Blood tests
• Stress test

Treatment

The initial treatment for high output heart failure is aimed at restoring your body to a stable state. Depending on the severity of your heart failure, you may need to take prescription medications, such as beta-blockers or diuretics, or require ventilation and, in some cases, intubation.

Once your body is stabilized, the treatment for high output heart failure depends on the underlying cause.

Certain lifestyle changes can help treat heart failure, including:

• Exercising regularly
• Introducing a low-sodium diet
• Managing stress
• Quitting smoking
• Avoiding alcohol
• Getting more sleep

If your heart failure gets worse, surgery or transplantation may be required.

Prognosis

The prognosis for high output heart failure depends on the underlying cause and severity of heart failure. Low vascular resistance, or lower blood pressure caused by widespread dilation of the blood vessels, is associated with poorer outcomes.

For all cases, focusing first on stabilizing your heart failure symptoms and then focusing on treating the underlying disease can increase your quality of life.

Pay attention to your body and your symptoms. If symptoms worsen at any point, don’t hesitate to seek medical help.

A Word From Verywell

Living with a condition such as heart failure can feel overwhelming, but seeking out a medical team to provide you with direction, support, and answers can help you feel more in control.

Take care of yourself and do your best to adopt a healthier lifestyle. Talk to your doctor about heart-healthy lifestyle changes you can make such as managing stress, getting regular exercise, and changing your diet.