Atrial fibrillation, or "AFib," is the most common type of serious arrhythmia, affecting about 2.2 million Americans, with 160,000 new cases diagnosed annually.
AFib is a very fast and irregular rhythm originating in the atria (upper chambers of the heart). AFib occurs when the heart’s electrical signal begins in a different part of the atrium other than where it is supposed to begin, the sinoatrial (SA) node, which is known as the pacemaker of the heart.
When this happens, the electrical signal does not travel through the normal pathways in the atria, but instead may spread throughout the atria in a fast and disorganized manner. This causes the walls of the atria to quiver very fast (fibrillate) instead of beating normally. As a result, the atria are not able to adequately fill with blood or pump blood in sufficient amounts.
AFib and other supraventricular (originating above the ventricles) arrhythmias can occur for no apparent reason. Most of the time, however, supraventricular arrhythmias are caused by an underlying condition that interferes with the heart's ability to conduct electrical impulses. These conditions include high blood pressure (hypertension), coronary artery disease, heart failure or rheumatic heart disease. Other conditions also can lead to AFib, including overactive thyroid gland (too much thyroid hormone produced) and heavy alcohol use. AFib also becomes more common as people get older.
AFib is divided into different categories, based on the cause and duration of irregular-heartbeat episodes. Although symptoms may be the same across multiple types of AFib, the treatment options may be different. It is important to remember that all types of AFib increase the risk of stroke, even if no symptoms are present.
AFib episodes are inconsistent and unpredictable, and symptoms may come and go. Episodes can occur frequently, or they may only occur a few times a year. Each episode may last only a few minutes or could persist for hours or even days. Some people with paroxysmal fibrillation do not require treatment if the episodes resolve on their own, while others may need consistent treatment. It is not uncommon for AFib to begin as paroxysmal fibrillation and progress to a more permanent form of the condition over time.
When an irregular heartbeat lasts for more than seven days, it is called persistent AFib. This type of arrhythmia does not resolve on its own and requires ongoing treatment.
When the heartbeat is constantly irregular, lasting more than 12 months, it is called long-standing, persistent AFib. Medical or surgical treatment is necessary to regulate and maintain a healthy heartbeat.
With permanent AFib, an irregular heartbeat cannot be reset and maintained at a normal rate for an extended period of time, even with treatment. Physicians may recommend medication to help prevent blood clots.
AFib that is not caused by a heart-valve problem is called nonvalvular. It may be caused by another condition, like high blood pressure, or the cause may be unknown.
Causes and risk factors of heart arrhythmia include:
It is important to remember that AFib does not always cause symptoms. Patients who do experience symptoms may notice any of the following:
If you experience chest pain or pressure, it is important to call 911 or go to the nearest emergency room immediately.
AFib symptoms can be similar to symptoms of other conditions, including anxiety and panic. Because it can be difficult to determine if your symptoms are from AFib or from another condition, it is important to see your physician. If you need a physician referral, please call (713) 222-CARE (2273).
Tests to find underlying heart diseases, like atrial fibrillation, may include:
The innovative team at Memorial Hermann is here to help you find the treatment you need. For more information on diagnostic procedures to minimally invasive treatments for your thoracic condition, fill out the form below or call to schedule an evaluation.
If you’d like a referral to a heart and vascular specialist or want more information about our services, please fill out the form below or call us at (713) 219-3519. For other inquiries, such as obtaining medical records, imaging reports or test results, please call (713) 222-CARE (2273).
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