How is atrial fibrillation diagnosed?

 A doctor will usually diagnose atrial fibrillation by taking a detailed medical history and doing a physical exam. They may also order some tests, such as:
-an electrocardiogram (ECG or EKG), which records the heart's electrical activity;
-a chest X-ray;
-an echocardiogram (echo), which uses sound waves to create a picture of the heart;
-a Holter monitor, which is a portable ECG that you wear for 24 hours to record your heart's electrical activity;
-an event recorder, which is like a Holter monitor but you press a button to start recording when you experience any symptoms of atrial fibrillation.