Heart failure
Left heart failure
What is left heart failure?
Left heart failure is the most common type of heart failure.
The left side of your heart pulls oxygen-rich blood from your lungs and pumps it back out into your body.
If you have left heart failure, that means your left ventricle (shown in red in the animation below), isn’t working properly. Your heart is unable to push blood out to your body efficiently and it will struggle to draw blood from your lungs.
In a normal heart, the left ventricle should be able to squeeze 50% to 75% of its blood out into the body with each contraction. In a failing heart, that percentage, which is called the ejection fraction, will be 40% or less.
Blood will tend to pool in your lungs, and your body will not get enough oxygen to function as it should.
When this happens, you may have difficulty breathing, and you may compensate by panting and trying to breathe more rapidly.
You may also suffer from extreme tiredness.
There are two types of left heart failure. They used to be known as systolic (systole is the contraction-and-pumping phase of your heartbeat) and diastolic (diastole is the phase of your heartbeat when the ventricles expand to draw blood in). However, your doctor is now more likely to talk about “heart failure with a reduced ejection fraction”, abbreviated to HFrEF, or “heart failure with a preserved ejection fraction”, abbreviated to HFpEF.
Left heart failure: Left ventricle and ejection fraction
With HFrEF, your left ventricle is weak and can’t squeeze hard enough to pump more than about 40% of the blood out. With HFpEF, it is stiff or weak and doesn’t fill properly.
HFrEF is usually a mixture of systolic and diastolic dysfunction. HFpEF is purely diastolic.
If you want learn more about a normal heartbeat take a look at Your heart: The basics.
What causes left heart failure?
Heart failure can have many different causes. Anything that damages the heart or interferes with its ability to function can ultimately result in heart failure.
Most of the time, left heart failure is the result of coronary artery disease or a heart attack. But there are other conditions or behaviors that can cause cardiomyopathy and that will ultimately lead to heart failure. These include things like substance abuse, cardiac infections, and adverse reactions to chemotherapy.
Common causes of left heart failure include:
- Coronary artery disease
- Heart damage from a previous heart attack
- Under- or untreated hypertension
- Heart valve disorders, particularly mitral valve regurgitation
- Heart inflammations or infections, such as myocarditis
- Cardiomyopathy (a weakened or enlarged heart muscle) from other causes
- Obesity may increase your risk of heart failure
What are the symptoms of left heart failure?
The key symptom of left heart failure is shortness of breath, especially when exercising. You may, for example, find it difficult to carry on a conversation while walking.
A related symptom is shortness of breath when lying down. This happens because fluid tends to build up in your feet and legs if your heart is not able to pump properly and, when you lie flat, some of that fluid moves to your upper body and causes lung congestion (it can also cause frequent urination at night). People with left heart failure often need to sleep propped up in order to be able to breathe properly.
Fluid retention in your legs and feet will make them swell and you may find that your shoes are a very tight fit.
Common symptoms of left heart failure include:
- Shortness of breath on exertion, even with very mild exercise
- Difficulty breathing while lying down; waking up short of breath and needing to sit upright in order to breath
- Swelling in the feet and legs
- Rapid heartbeat
- Tiredness
How is left heart failure treated?
Your doctor will determine the best course of treatment based on the severity of your left heart failure. If you have mild heart failure, and it is stable, treatment may focus on lifestyle changes, such as exercising more or losing weight.
In addition, you may need to take medications such as beta blockers, ACE inhibitors, or angiotensin receptor blockers. These drugs can help your heart to recover and pump more effectively.
Diuretics may be prescribed to reduce your fluid load and help you to manage symptoms such as swollen feet and ankles.
If your left heart failure is severe, your doctor may recommend surgery to implant a pacemaker or an ICD (implantable cardioverter defibrillator). In the most severe cases, a cardiac assist device or heart transplantation may be required.
Treatments for left heart failure include:
- Lifestyle changes: Losing weight, eating a healthy diet, exercising more, and quitting smoking
- Medications that will help your heart heal and recover its ability to pump
- Diuretics to help manage your fluid load and reduce swelling
- Surgical insertion of an ICD, if your ejection fraction is 35% or less and you are not responding to other treatments
- Surgical insertion of a biventricular pacemaker (in severe cases)
- Cardiac assist device to help your heart pump (in severe cases)
- Heart transplantation (in severe cases)
What are the aims of treatment?
The aims of treatment for people with left heart failure are to relieve symptoms like breathlessness and swelling, to help your heart to recover and beat more effectively, and to prevent or slow further weakening of your heart muscles.