Atrial Fibrillation (AFib) Quiz!
Can you guess the correct answer?
Having atrial fibrillation puts a person at risk for:
Atrial fibrillation (also referred to as AFib, Afib, A-fib, and AF) is an irregular and often rapid heart rhythm. The irregular rhythm, or arrhythmia, results from abnormal electrical impulses in the upper chambers (atria, singular=atrium) of the heart that cause the heartbeat (ventricle contraction) to be irregular and usually fast. The abnormal heart rhythm can be continuous, or it can come and go. Some individuals, especially patients on medications, may have atrial fibrillation constantly but not have a rapid (>100 heartbeats per minute) rate at rest. Variations of AFib may be termed paroxysmal, persistent, or permanent (these are further described below). AFib is the most common heart arrhythmia.
Normal heart contractions begin as an electrical impulse in the right atrium. This impulse comes from an area of the atrium called the sinoatrial (SA) or sinus node, the "natural pacemaker" that causes the normal range of regular heartbeats. Normal heartbeats proceed as follows:
In an adult person with a normal heart rate and rhythm the heart beats 50-100 times per minute at rest (not under stress or exercising).
In atrial fibrillation, multiple sources of impulses other than only from the SA node travel through the atria at the same time. The reason that these sources develop are not completely understood, but cardiac muscles in the pulmonary veins have electrical generating properties and may be one source of these extra impulses.
Atrial fibrillation can occur in several different patterns.
Atrial fibrillation, often called AFib, atrial tachyarrhythmia, or atrial tachycardia, is one of the very common heart rhythm disorders.
For many people, atrial fibrillation may cause symptoms but does no harm.
Atrial fibrillation may occur without evidence of underlying heart disease. This is more common in younger people, about half of whom have no other heart problems. This is often called lone atrial fibrillation. Some of the causes that do not involve the heart include the following:
Most commonly, atrial fibrillation occurs as a result of some other cardiac condition (secondary atrial fibrillation).
Atrial fibrillation frequently occurs after cardiothoracic surgery or procedures, but often resolves in a few days.
For many people with infrequent and brief episodes of atrial fibrillation, the episodes are brought on by a number of triggers. Because some of these involve excessive alcohol intake or skipping medications, this is sometimes called "holiday heart "or "Saturday night heart." Some of these people are able to avoid episodes or have fewer episodes by avoiding their triggers. Common triggers include alcohol and caffeine in susceptible individuals.
Symptoms of atrial fibrillation vary from person to person.
There are a few patients who have potentially life-threatening AFib symptoms that need immediate attention and intervention with electric cardioversion. The symptoms and signs are as follows:
Individuals should call for treatment within 24 hours if they have atrial fibrillation that comes and goes, have previously been evaluated and treated, and are not experiencing chest pain, shortness of breath, weakness, or fainting.
Patients should call their doctor or cardiologist if they have persistent atrial fibrillation while on medical therapy for the condition if symptoms worsen or new symptoms such as fatigue or mild shortness of breath occur.
Patients should call their doctor or pharmacist if they have questions about medications and dosages.
Call 9-1-1 for emergency medical services when atrial fibrillation occurs with any of the following:
Not all heart palpitations are atrial fibrillation, but a continuing feeling of heart fluttering in the chest together with a fast or slow pulse should be evaluated by a doctor or at a hospital emergency department. For example, the patient could be having atrial flutter (rapid, regular electrical impulses of about 250-300 impulses per minute from the atrial tissue causing a rapid ventricular response [rvr] or rapid heartbeat) or a sinus tachycardia.
The doctor will often begin by asking patients about their medical history to help determine the severity of symptoms. The doctor will assess if any associated factors (for example, alcohol or caffeine intake) may be contributing to the patient's symptoms. The doctor will also listen to the patient's heartbeat and lungs. The evaluation may include the following tests:
Lab tests: There is no blood test that can confirm that a person has atrial fibrillation. However, blood tests may be done to check for certain underlying causes of atrial fibrillation and to rule out heart damage, as from a heart attack. People already taking medication for atrial fibrillation may need blood tests to make sure there is enough of the drug (usually digoxin) in their system to work effectively. Blood tests that may be done to rule out other conditions include:
Ambulatory electrocardiogram (Holter monitor): This test involves wearing a monitor similar to that used for an ECG for a period of time (usually 24-48 hours) to try to document the arrhythmia while people go about their everyday activities.
Electrocardiogram (ECG or EKG): This is the primary test to determine when an arrhythmia is atrial fibrillation. The ECG can help the doctor distinguish AFib from other arrhythmias that may have similar symptoms (atrial flutter, ventricular tachycardia, or runs of ventricular tachycardia). The test can also sometimes reveal damage (ischemia) to the heart, if there is any.
The following is an illustration showing the usual ECG tracing from a patient with AFib.
Rapid heart rate ECG of a patient with atrial fibrillation. SOURCE: Image reprinted with permission
from Medscape.com, 2012.
Doctors who treat atrial fibrillation include
In making the diagnosis, a patient's doctor will consider the severity of symptoms and whether they are new or have been going on for some time. The patient may be referred to a specialist in heart disorders (cardiologist) during this evaluation. Choice of treatment for atrial fibrillation depends on the type of AFib, the severity of symptoms, the underlying cause, and the patient's overall health. General guidelines for AFib treatment are available, but most doctors modify guidelines to best treat the individual, so treatment is patient-specific.
There is no effective home treatment for atrial fibrillation while it is occurring. However, if the doctor recommends lifestyle changes or prescribes medicine, follow his or her recommendations exactly. Lifestyle changes may prevent AFib associated with holiday heart. In addition, careful adherence to medication at home may also prevent many episodes of AFib. This is the only way to see whether the medical treatment works or needs adjustment.
Treatment for atrial fibrillation traditionally seeks three goals: to slow down the heart rate, to restore and maintain normal heart rhythm, and to prevent blood clots that may lead to strokes.
Cardioversion (also termed defibrillation): This technique uses electrical current to "shock" the heart back to normal sinus rhythm with an electrical current. This is sometimes called DC cardioversion. Prior to cardioversion, many patients undergo a sonogram of the heart to determine if any clots are present.
Catheter ablation (radiofrequency [RF] ablation) is a catheter-based technique that electrically burns/destroys some of the abnormal conduction pathways in the atria using radio waves.
Pacemaker: A pacemaker is an electronic device that prevents slow heartbeats and may reduce the likelihood of atrial fibrillation in a small number of patients. The artificial pacemaker takes the place of the "natural pacemaker," the SA node, supplying electrical impulses to keep the heart beating in a normal rhythm when the SA node no longer can.
The choice of medication depends on the type of atrial fibrillation diagnosed, the underlying cause, other medical conditions that contribute to the patient's overall health, and other medications. Ironically, many anti-arrhythmia medications may induce abnormal heart rhythms.
Anti-arrhythmia (anti-arrhythmic) medications include:
Other drugs are used to help patients avoid blood clot formation that may lead to strokes or additional health problems. The decision to utilize other drugs can be augmented by the CHADS2 (also termed CHA2DS2-VASc) score that assigns points to various conditions (congestive heart failure, hypertension, age, diabetes, and previous stroke) in an AFib patient. The higher the points, the more likely the patient is to develop a stroke; some clinicians use this score to help determine what other drugs may help their patients with AFib avoid a stroke.
The above is an overview of the many drugs that doctors may choose to treat AFib. However, each individual is unique, so the treatments vary depending on the medical condition of the patient (for example, presence of a pacemaker or compromised renal function). Those interested can see extensive guidelines for various patients in the American Heart Association journal Circulation.
Before the development of catheter ablation, open heart surgery was done to interrupt conducting pathways in both atria. This is called the surgical maze procedure. Maze surgery is usually considered in patients who need some other type of heart surgery, such as valve repair or coronary artery bypass surgery.
If patients have no other ongoing heart problems and medications succeed in controlling the patient's heart rate, the patient may be sent home from the emergency department. This is often done after consultation with the patient's doctor or cardiologist. Patients should follow up with their health care professional within 48 hours.
If the heart rhythm does not convert to normal by itself, the patient may need electrical cardioversion or defibrillation.
Individuals who do not have atrial fibrillation can lower their chance of getting this arrhythmia by minimizing risk factors. This includes minimizing the risk factors for coronary heart disease and high blood pressure listed below.
If patients have atrial fibrillation, their health care professional may prescribe treatments for the underlying cause and to prevent future episodes of atrial fibrillation. These treatments might include any of the following (see Medical Treatment for more information):
In general, the outlook for most individuals with AFib is good to fair, depending on the cause of the disease and how well the patient responds to treatment. The most dangerous complication of atrial fibrillation is stroke.
Another complication of atrial fibrillation is heart failure.
Patients with complications of stroke or heart failure have a more guarded outcome than those without complications. However, for most people with atrial fibrillation, relatively simple treatment dramatically lowers the risk of serious outcomes. Those who have infrequent and brief episodes of atrial fibrillation may need no further treatment other than learning to avoid the triggers of their episodes, such as caffeine, alcohol, or overeating.
Having atrial fibrillation puts a person at risk for: