Nonvalvular atrial fibrillation: Get the facts
The heart pumps blood around the body with a fairly even rhythm. But sometimes there can be a problem that causes the heart to beat irregularly.
Atrial fibrillation, often referred to as A-fib or AF, means that the heart works less efficiently, which can cause several health problems.
There are many treatment options and lifestyle changes that can help people with nonvalvular A-fib to live normally. Treatment can also prevent a stroke, which is a risk for those with the condition.
The heart works less efficiently in people with atrial fibrillation.
What does nonvalvular atrial fibrillation mean?
- "Atrial" means to do with the atria or the top two chambers of the heart.
- "Fibrillation" is a rapid and irregular tightening of muscle fibers.
- "Valvular" refers to the heart valves that let blood in and out of the heart.
So, nonvalvular A-fib is an irregular heart rhythm in the upper chambers of the heart that is not caused by a fault with the heart valves.
Nonvalvular A-fib can cause a number of problems, including blood pooling in parts of the heart. The consequence of this pooling can mean that less blood is available to be pumped to the rest of the body. If a blood clot forms in the pooled blood, it could reach the brain and cause a stroke.
An irregular heart rhythm can make it harder for the heart to pump blood to the rest of the body, causing dizziness or fatigue.
A-fib is a serious condition that affects at least 2.7 million Americans, according to the American Heart Association. If untreated, it can double the risk of death from a heart-related condition. It can also make it five times more likely that a person will have a stroke.
Causes and risk factors
There are many different causes of A-fib, and there are some risk factors that are specific to nonvalvular A-fib. Many of these relate to the heart being less healthy or weakened.
Groups at risk of A-fib include:
- men, who are more likely to have the condition than women
- older adults, as the risk for A-fib increases with age
- people who have high blood pressure
- people who have a history of heart disease, such as heart attack
Conditions that specifically increase the risk of developing nonvalvular A-fib include:
- lung disease
- regularly drinking a lot of alcohol
- sleep apnea
- metabolic syndrome, which increases the risk of heart disease
- an overactive thyroid gland or hyperthyroidism
High-dose steroid therapy may also be a trigger if someone has other A-fib risk factors.
Symptoms and complications
A quivering or fluttering heartbeat is a common symptom of A-fib.
It is possible to live with A-fib and not experience any symptoms.
Many of the symptoms that A-fib does cause could also indicate other medical conditions. As a result, it is sensible for someone to consult a doctor for a diagnosis.
The most common symptom of A-fib, whether valvular or nonvalvular, is a quivering, fluttering, or rapid heartbeat, or a thumping feeling in the chest, alongside an irregular pulse.
Other symptoms could include:
- dizziness or fainting
- shortness of breath or difficulty breathing
- feeling weak, particularly after exercise
Chest pain or pressure can be a symptom but should be treated as a medical emergency. This may be a sign that a person is having a heart attack.
Someone who has A-fib should also be aware of the symptoms that could indicate a stroke, as they are at increased risk of stroke.
A-fib can be diagnosed by a doctor. They will carry out a physical examination and ask questions about a person's medical history.
A doctor will usually perform an electrocardiogram, also known as an EKG or ECG. This is a simple test that shows how fast the heart is beating, detects an irregular heart rhythm, and can tell how strong the electrical signals are passing through each part of the heart.
Someone having an EKG or ECG should expect to lie still on a table while electrodes are attached to the skin on the chest, arms, and legs. These electrodes are connected to a machine that records information about the heart's electrical activity.
The skin may need to be shaved so that the electrodes stick, but the test is painless, and there are no risks.
An EKG or ECG only records one moment of the heart's activity and may not capture the irregular heart rhythm. If the result is not satisfactory or incomplete, the doctor will order a 24-48-hour Holter monitor.
In this case, several electrodes will be placed on the chest and connected to a recording device. Events are recorded that happen during the time monitored, for example, when an individual is jogging or eating breakfast.
After the time expires, the monitor will be returned to the doctor who will review the results and discuss any necessary treatment plans.
Treatment will vary according to symptoms, how severe the symptoms are, and whether a person already has heart disease.
If there are no symptoms or related heart problems, the heart may return to a normal rhythm without treatment.
The main goals of treatment are:
- to prevent blood clots that could lead to a stroke
- to restore a normal heart rhythm
- to control how many times a minute the chambers of the heart contract and fill with blood
By controlling the number of times the chambers of the heart contract, fewer symptoms are experienced, even if the heart continues to beat out of time. This last treatment goal is known as rate control.
Lifestyle changes, such as reducing the intake of alcohol, may be recommended.
Lifestyle changes that are often recommended to someone with A-fib include:
- cutting back on salt to reduce high blood pressure
- following a healthful diet
- reducing stress
- avoiding alcohol or limiting the amount drunk
Research is not clear on whether caffeine can cause A-fib or makes it worse. Some people are more sensitive to caffeine. Those who are caffeine-sensitive may choose to avoid it or reduce their intake by avoiding products that contain a lot of caffeine, such as espresso coffee or energy drinks.
Medication that may be prescribed to people with nonvalvular A-fib include:
- blood-thinning medication to prevent blood clots and the risk of stroke
- medication for rate control, such as beta-blockers
- medication to restore a normal heart rhythm, such as amiodarone
Novel oral anticoagulants (NOACs are the preferred type of medication for treating A-fib.
Taking heart medication as prescribed is one of the most important things a person can do to ensure continuing health. However, there can be side effects, and some medication may work better if a certain diet is followed.
Monthly blood tests are often necessary if someone is taking warfarin, to ensure there are no adverse side effects.
For these reasons, it is important for people with A-fib to seek clear information from the doctor who prescribed their medication.
Medical procedures that could be needed for nonvalvular A-fib include:
- Electrical cardioversion: Low-energy electrical shocks are given to the heart.
- Catheter ablation: Radiowave energy is sent through a wire in the leg or arm to the heart, to destroy unhealthy tissue that can disrupt the electrical signals.
- Maze heart surgery: Small cuts are made in the upper part of the heart and stitched together to form scar tissue that affects the heart's electrical signals and restores a normal heartbeat.
- Pacemaker: A small, electrical device is introduced under the skin and sends an electrical pulse to the heart to keep it beating with a normal rhythm.
Nonvalvular A-fib can be a serious condition if left untreated. However, there is a range of options available to bring the heart back into a healthy rhythm or to lessen symptoms.
A good way to prevent and manage nonvalvular A-fib is for an individual to lower the risk of developing or worsening heart disease.
Ways that people can do this include taking medication as prescribed, trying to lower cholesterol levels, and doing gentle exercise regularly.