Atrial Fibrillation

Diagnosis

Mayo Clinic doctors trained in heart conditions (cardiologists), cardiologists trained in heart rhythm disorders (electrophysiologists) and other doctors evaluate and treat people who have atrial fibrillation and other heart rhythm conditions.

To diagnose atrial fibrillation, your doctor may review your symptoms, and your family and personal medical history. Your doctor will conduct a physical examination and order several tests to determine the cause of your symptoms and diagnose your condition.

• Blood tests. Your doctor may order blood tests to check thyroid hormone levels and electrolyte levels in your blood.
• Chest X-ray. A chest X-ray takes images of your chest, heart and lungs, which may help your doctor to see if your heart is enlarged.
• Echocardiogram (Doppler echocardiogram). In this test, sound waves create detailed images of your heart's size, structure and motion. Your doctor sometimes may order a transesophageal echocardiogram. In this test, a doctor inserts a flexible tube with a probe (transducer) attached into your esophagus to take detailed images of your heart.
• Electrocardiogram (ECG). In an ECG, doctors place sensor patches (electrodes) on your skin to measure the electrical impulses given off by your heart. An ECG measures the timing and rhythm of each electrical phase in your heartbeat.
• Event recorder. An event recorder is a portable ECG device that you can activate when you experience symptoms.
• Holter monitor. A Holter monitor is a portable ECG device that you wear for a day or more to record your heart's electrical activity during your daily routine.
• Stress test. In a stress test, your heart is monitored by an ECG or other tests as you exercise on a treadmill or stationary bicycle. If you have difficulty exercising, your doctor may give you a drug to help stimulate your heart in a similar way as during exercise.

Read more about chest X-rays, echocardiogram, electrocardiogram, Holter monitor and stress test at MayoClinic.com.