Diagnosis - Atrial fibrillation

Checking your pulse is a useful first step in helping to diagnose atrial fibrillation.

Checking your pulse

To check your pulse:

1. Sit down for 5 minutes. Do not smoke or drink caffeine before checking your pulse.
2. Hold your left hand out with your palm facing up and elbow slightly bent.
3. Firmly place the index and middle finger of your right hand on your left wrist - between your wrist bone and the tendon on your thumb.
4. Using the second hand on a clock or watch, count the number of beats for 30 seconds. Then double that number to get your heart rate in beats per minute.

At rest, a normal heart rate should be 60 to 100 beats per minute. In atrial fibrillation, the heart rate can often be much higher than 100 beats per minute, and the rhythm is irregular.

Checking your pulse can give you a good idea of whether you have atrial fibrillation. But a full medical investigation is needed before a diagnosis can be made.

If they think you might have atrial fibrillation, your GP may:

• arrange a trace of your heart (electrocardiogram)
• refer you to a heart specialist (cardiologist) for more tests

Electrocardiogram (ECG)

An ECG is a test that records your heart's rhythm and electrical activity. It's usually done in a hospital or GP surgery. It takes about 5 minutes, and is painless.

During an ECG, small stickers called electrodes are attached to your arms, legs and chest. These are connected by wires to an ECG machine.

Every time your heart beats, it produces tiny electrical signals. An ECG machine traces these signals onto paper.

During an episode of atrial fibrillation, your heart rate will be irregular and over 100 beats per minute.

If you have an episode of atrial fibrillation during an ECG, your abnormal heart rate will be recorded. This will confirm the diagnosis of atrial fibrillation and rule out other conditions.

Sometimes it can be difficult to capture an episode of atrial fibrillation. You may be asked to wear a small portable ECG device at home. This fits onto your wrist like a watch and records your ECG when you have palpitations.

Electrocardiogram (ECG)

Other tests

If you have atrial fibrillation, you may need other tests, including:

• an echocardiogram - an ultrasound scan of the heart, which can help identify any other heart-related problems
• a chest x-ray - this can help identify any lung problems that may be causing atrial fibrillation
• blood tests - these can highlight other problems, such as infection, anaemia, problems with kidney function, or an overactive thyroid gland