Feeling the patient's pulse can give a healthcare professional enough data to suspect atrial fibrillation. However, to be completely sure the patient will need to undergo a full medical investigation. This may include:
An ECG (electrocardiogram)
Electrodes are attached to the patient's skin to measure electrical impulses given off by the heart. The impulses are recorded as waves and displayed on a screen (or printed).
This test will also show any previous heart disease that may have contributed to the atrial fibrillation. The irregularity of the heart action is generally obvious right away.
The patient wears a portable device which records all his/her heartbeats. It is worn under the clothing and records information about the electrical activity of the heart while the patient goes about his/her normal activities for one or two days. It has a button which can be pressed if symptoms are felt - then the doctor can see what heart rhythms were present at that moment.
This machine is similar to a holter monitor, but it does not record all the heartbeats. There are two types:
- One uses a phone to transmit signals from the recorder while the patient is experiencing symptoms.
- The other is worn all the time for a long time; sometimes as long as a month (it must be taken off when showering or having a bath).
This device is good for diagnosing rhythm disturbances that happen at random moments.
This is a type of ultrasound test that utilizes high-pitched sound waves that are sent through a transducer - a wand-like device that is held on the chest. The transducer picks up echoes of the sound waves as they bounce off different parts of the patient's heart.
The data is presented on a video screen where the doctor can see the heart as it moves.
This test can help a doctor identify underlying structural heart disease.
These help determine whether thyroid problems, or other substances may be factors contributing to the patient's atrial fibrillation.
Blood tests can also reveal whether the patient has anemia, or problems with kidney function, which could complicate atrial fibrillation.
Serum electrolytes may also be tested to evaluate sodium and potassium levels.
The images help the doctor check the state of the patient's heart and lungs. A chest X-ray may also help a doctor determine whether the patient has any congenital heart defects.
Other conditions that may explain the signs and symptoms might also be detected.
If the patient experiences fainting spells, dizziness or lightheadedness, and neither the ECG nor the Holter revealed any arrhythmis, a tilt-table test may be performed. This monitors the patient's blood pressure, heart rhythm and heart rate while he/she is moved from a lying down to an upright position.
A healthy patient's reflexes cause the heart rate and blood pressure to change when moved to an upright position - this is to make sure the brain gets an adequate supply of blood.
If the reflexes are inadequate, they could explain the fainting spells, etc.
Electrophysiologic testing (or EP studies)
This is an invasive, relatively painless, non-surgical test and can help determine the type of arrhythmia, its origin, and potential response to treatment.
The test is carried out in an EP lab by an electrophysiologist, and makes it possible to reproduce troubling arrhythmias in a controlled setting. During an EP study:
- The patient is given a local anesthetic.
- After an initial puncture an introducer sheath is inserted into a blood vessel.
- A catheter is inserted through the introducer sheath and is threaded up the blood vessel, through the body and into the right chambers of the heart.
- The electrophysiologist can see the catheter moving up the body on a monitor.
- When it is inside the heart the catheter stimulates the heart and records where abnormal impulses start, their speed, and which normal conduction pathways they bypass.
- Treatments can be given to find out whether they stop the arrhythmia.
- The catheter and introducer sheaths are then removed, and the insertion site is closed up either by applying pressure to the site or with stitches.