Atrial fibrillation, also known as A-fib, is a common irregular heart rhythm that affects an estimated 3 million Americans. The most common symptoms of new atrial fibrillation are a racing irregular heartbeat, palpitations, shortness of breath, and fatigue when walking. In some cases, the person has no symptoms and the atrial fibrillation is only noticed during a routine medical examination.
Doctors confirm the diagnosis of atrial fibrillation using an ECG (electrocardiogram): Electrodes are taped to the skin, and the irregular electrical activity of the heart creates a characteristic tracing, which is read by doctors.
In many cases, atrial fibrillation is actually brought on by some other medical condition affecting the heart or body. For this reason, it's important that a person with a new diagnosis of atrial fibrillation be checked for these related conditions. In some cases, correcting a related condition can cause the atrial fibrillation to go away.
Here's what the doctor should check for, and the tests usually used:
An enlarged heart is more prone to develop atrial fibrillation, especially if the upper chambers of the heart become dilated.
Test used: An echocardiogram can assess heart function and the size of the heart's chambers.
A leaky or stiff heart valve can sometimes put strain on the heart's upper chambers (the atria) and provoke atrial fibrillation.
Test used: An echocardiogram assesses the heart's valves and their function.
Chronic high blood pressure has been linked with a higher risk of developing atrial fibrillation.
Test used: Blood pressure should be routinely checked at most doctor visits.
High levels of thyroid hormone
A high level of thyroid hormone in the body can rev up the heart and cause atrial fibrillation. High thyroid levels can be due to a hyperactive thryoid or can be caused by overshooting on thyroid replacement medication.
Test used: A simple blood test can check thyroid function and thyroid hormone levels.
Heavy alcohol use
Binge drinking and chronic heavy use (three or more drinks/day) have been linked with atrial fibrillation.
Test used: Short office-based interview question or questions. Note: Laboratory tests of blood and urine aren't routinely used to identify problem drinkers.
Other conditions related to atrial fibrillation
Atrial fibrillation has also been linked to other medical conditions, including coronary artery disease, COPD, sleep apnea, pneumonia, and heart surgery. However, these conditions aren't routinely checked for after a new diagnosis, because it's rare for atrial fibrillation to be the first or only sign of these conditions.
For more on how A-fib is diagnosed, see FAQ: How Is Atrial Fibrillation Diagnosed?
For more on how A-fib is managed, see how to decide between rate control and rhythm control and how to decide which blood thinner to use.