To diagnose a heart arrhythmia, your doctor will review your symptoms and your medical history and conduct a physical examination. Your doctor may ask about — or test for — conditions that may trigger your arrhythmia, such as heart disease or a problem with your thyroid gland. Your doctor may also perform heart-monitoring tests specific to arrhythmias. These may include:
- Electrocardiogram (ECG). During an ECG, sensors (electrodes) that can detect the electrical activity of your heart are attached to your chest and sometimes to your limbs. An ECG measures the timing and duration of each electrical phase in your heartbeat.
- Holter monitor. This portable ECG device can be worn for a day or more to record your heart’s activity as you go about your routine.
- Event recorder. For sporadic arrhythmias, you keep this portable ECG device available, attaching it to your body and pressing a button when you have symptoms. This lets your doctor check your heart rhythm at the time of your symptoms.
- Echocardiogram. In this noninvasive test, a hand-held device (transducer) placed on your chest uses sound waves to produce images of your heart’s size, structure and motion.
- Implantable loop recorder. If your symptoms are very infrequent, an event recorder may be implanted under your skin in the chest area to continually record your heart’s electrical activity and detect abnormal heart rhythms.