holter-monitorAtrial Fibrillation tests and investigations in London

Prove it is AF

The most important thing is to confirm whether you do have AF or not. This is done by recording the electrical activity of the heart during your symptoms (or when your heart is fast and irregular if you do not have symptoms). Recording the electrical activity of the heart is called an electrocardiogram (ECG). This can be done either in a doctors surgery on a fixed machine, or with a device that you can carry around separately or on your phone or a long ECG recording called a Holter monitor or event recorder and many watches are now capable of recording an ECG. It is also important that someone competent looks at the results. Even cardiologists who do not specialise in heart rhythm problems may get it wrong. A single lead ECG recorded by a watch or hand held ECG machine during symptoms is usually enough to confirm or refute AF.

For patients with no symptoms and rare episodes it is usually not important to make the diagnosis unless that patient has a high risk of stroke (CHADSVasc>1) or AF is being excluded as a cause of stroke. If this is the case then a loop recorder can be helpful. This is a device that is injected under the skin and can record the ECG continuously for up to 3-4 years. These devices have algorithms that detect AF and let us know if AF is present.

Check for an underlying cause for the AF:

  1. Your blood pressure measured to exclude hypertension (high blood pressure)
  2. Your thyroid function measured with a blood test
  3. An echocardiogram to exclude structural heart disease that is sometimes impossible to detect with an examination

Once other causes for AF have been excluded or treated then you must make a decision as to how you want your AF treated. If you opt to accept AF and simply have you heart rate controlled, recording the ECG during exercise or with a 24 hour Holter recording will give a much better idea of what your heart rate control is than just one examination at rest.