Atrial fibrillation is the most common electrical problem of the heart. Although atrial fibrillation by itself is not a lethal disease, it can result in severe strokes and is associated with increased risk of death. In this article, Part 1 of a two-part series, we summarize the problems associated with atrial fibrillation and ways to treat it. In Part 2, we discuss risk factors that can lead to atrial fibrillation and how to prevent it.
What Is Atrial Fibrillation?
Atrial fibrillation, or AFib, is a type of arrhythmia, or irregular heartbeat, and is a disease of the electrical system of the heart. The heart has two upper chambers, called atria, and two lower chambers, called ventricles. The atria receive blood from the rest of the body and push it to the ventricles. The ventricles push blood to the lungs and the entire body. In patients with atrial fibrillation, the upper chambers of the heart do not squeeze blood to the lower chambers smoothly. Instead, they do so in a disorganized way that looks like shivering. In medical terms, this is called fibrillation, hence the disease name. Some patients get episodes of atrial fibrillation that come and go, known as paroxysmal atrial fibrillation, but others are constantly experiencing atrial fibrillation, known as persistent atrial fibrillation.
Patients with atrial fibrillation may experience a variety of symptoms. Because of the shivering of the upper chambers of the heart, the heartbeats become irregular and, in some cases, faster than normal. This makes patients with atrial fibrillation feel palpitations (i.e., feeling the heart pounding, thumping or fluttering), or a fast and irregular heartbeat. Patients may confuse the fast and irregular heartbeat with anxiety or a panic attack. Since the upper chambers of the heart do not contract smoothly, there is less filling of the lower chambers. This can make patients feel fatigued, dizzy, lightheaded, short of breath or tired during exercise. Occasionally, atrial fibrillation may cause chest pain or pressure. If you have ongoing chest pain or pressure, it is a medical emergency, and you may be having a heart attack. Call 911 immediately.
Sometimes, the only symptom you may have is fatigue. Atrial fibrillation does not always have symptoms, and many times, patients do not know they have it. Your primary care provider can tell whether you have atrial fibrillation by examining you — he or she will listen for an irregular heartbeat and feel for an irregular pulse — and looking at an electrocardiogram. Sometimes, wearing a heart rhythm monitor for a prolonged period of time (from two days up to one year) may be necessary to diagnose atrial fibrillation because it can come and go. It is essential to follow up with your doctor at the intervals recommended.
[See: 10 Ways to Lower Your Risk of Stroke.]
How Common Is Atrial Fibrillation?
Atrial fibrillation is the most common electrical problem of the heart. In 2010, an estimated 2.7 to 6.1 million patients had atrial fibrillation in the U.S., and 33.5 million had it worldwide. It is predicted that by 2030, 12.1 million Americans will have atrial fibrillation. Atrial fibrillation affects primarily older adults, and the risk of developing atrial fibrillation increases with age. Men are more likely to get atrial fibrillation compared to women, but on average women tend to get atrial fibrillation at an older age compared to men. African-Americans, Hispanics and Asians are 25 to 30 percent less likely to get atrial fibrillation compared to whites. African-Americans are less likely to be aware that they have atrial fibrillation compared to whites, and the reasons for this remain unknown.
Why Should I Worry About Atrial Fibrillation?
Although atrial fibrillation itself is not a lethal disease, patients who have atrial fibrillation overall have poorer outcomes and a higher risk of death. According to the American Heart Association, in 2013, atrial fibrillation was mentioned on 131,914 U.S. death certifications, and on 20,738 of those, it was listed as the primary cause of death. Men with atrial fibrillation have a 50 percent higher risk of death compared to those without it, and women with atrial fibrillation have a 90 percent higher risk of death. Newly diagnosed patients with atrial fibrillation have a high risk of death within the first four months of diagnosis. The most common causes of death are coronary artery disease (blockages in the vessels that feed the heart), heart failure (inability of the heart to pump blood) and stroke (blockage in the vessels that feed the brain). Often, atrial fibrillation is a marker or clue for the presence of underlying structural heart disease.
Stroke and the showering of blood clots to other organs (called thromboembolism) are the most devastating complications of atrial fibrillation. Patients with atrial fibrillation are five times more likely to have a stroke compared to those without. Because the upper chambers of the heart do not squeeze blood as well to the lower chambers, the blood can pool in the upper chambers, forming clots. These clots may dislodge, travel through arteries to the brain and cause a stroke. The strokes caused by atrial fibrillation can be severe and frequently result in permanent disability. Clots can also travel through arteries to other organs, such as the intestines, kidneys or legs, causing permanent damage. The risk of having a stroke or thromboembolism is similar in both paroxysmal and persistent atrial fibrillation.
Atrial fibrillation is also associated with dementia. Individuals with atrial fibrillation have twice the risk of developing dementia compared to those without. Long-standing atrial fibrillation can result in weakening of the heart muscle, a condition known as heart failure. Finally, atrial fibrillation is associated with a reduced quality of life, so it is important to understand how you can prevent it.
[See: 17 Ways Heart Health Varies in Women and Men.]
How Is Atrial Fibrillation Treated?
Atrial fibrillation treatment has three strategies: 1.) treatment of the arrhythmia and restoration of normal heart rhythm (rhythm control), 2.) preventing the heart from beating too quickly (rate control) and 3.) preventing stroke with anticoagulation therapy (blood thinners). Restoration of a normal heart rhythm is important for patients who have been newly diagnosed with atrial fibrillation and for those who have noticeable symptoms. Specialized medications called anti-arrhythmics — such as flecainide, propafenone, sotalol, dofetilide and amiodarone — or electrical cardioversion (delivery of an electrical shock to the heart) can restore heart rhythm. If these methods fail, a surgical procedure can be performed. For this procedure, specialized electrophysiologists burn or ablate the spots in the heart where the abnormal electrical activity originates and prevent it from further propagating across the heart. If a patient has the arrhythmia for a long period of time and does not experience symptoms, restoration of normal rhythm is not necessary. However, it is essential to ensure that the heart rate is not too fast. An acceptable heart rate depends on various factors, such as whether you have other types of heart disease. If you have atrial fibrillation, your doctor can tell you what heart-rate goals are appropriate for you. Some patients can stay under these goals without any intervention. For those who can’t, physicians use medications that slow down the heart, such as metoprolol, atenolol, diltiazem, verapamil and digoxin.
Last but not least, everyone who has atrial fibrillation, regardless of any symptoms, needs to be evaluated for stroke risk. If the risk is greater than 1 percent per year, then a blood thinner is recommended by multiple scientific societies to protect the patient from getting a stroke. Although all blood thinners effectively prevent stroke, their use causes an increased risk of bleeding. There are five blood thinners currently available: Warfarin is the oldest one on the market, and dabigatran, rivaroxaban, apixaban and edoxaban are newer medications. Warfarin is very effective in preventing stroke but requires the patient to frequently use a blood test to check how thin the blood is. The others are equivalent to warfarin in preventing stroke but are overall associated with fewer bleeding complications, and patients don’t need to monitor the levels of their blood thickness on them. For patients who are unable to take a blood thinner for life because of risk of bleeding or falls, special devices can be used. These devices block the part of the heart where blood clots are thought to form in atrial fibrillation and reduce the risk of stroke. However, these are invasive procedures, and there is some risk associated with the procedures themselves, so not all patients are candidates. If you have atrial fibrillation, ask your primary care provider to refer you to a cardiologist who manages atrial fibrillation and can review with you the pros and cons of these interventions, helping you decide on the best option.
[See: The Best Foods for Lowering Your Blood Pressure.]
Take-Home Points:
1. Atrial fibrillation is the most common arrhythmia.
2. Let your doctor know if you have palpitations, shortness of breath or fatigue, or if you notice a change in your endurance.
3. Many patients with atrial fibrillation have no symptoms at all. It’s important to ask your primary care provider to examine you and perform an electrocardiogram during your visit if you are at risk.
4. Atrial fibrillation is a condition associated with high risk of stroke. If you are diagnosed with atrial fibrillation, you need to establish care with a cardiologist and discuss treatment options.
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Atrial Fibrillation: Why You Should Worry and How to Avoid It originally appeared on usnews.com
