Diagnosis

Your doctor will listen to your heart using a stethoscope and ask questions about your medical history. He or she will also likely look for signs of medical conditions that can cause heart palpitations, such as a swollen thyroid gland.

If your doctor suspects that your palpitations are caused by an arrhythmia or other heart condition, tests might include:

• Electrocardiogram (ECG). In this noninvasive test, a technician places leads on your chest that record the electrical signals that make your heart beat.

  An ECG can help your doctor detect problems in your heartbeat and heart structure that could cause palpitations. The test will be done either while you rest or during exercise (stress electrocardiogram).

• Holter monitoring. You wear this portable device to record a continuous ECG, usually for 24 to 72 hours, while you keep a diary of when you feel palpitations. Holter monitoring is used to detect heart palpitations that aren't found during a regular ECG exam. Some personal devices, such as smart watches, offer ECG monitoring. Ask your doctor if this is an option for you.
• Event recording. If you don't have irregular heart rhythms while you wear a Holter monitor or if the events occur less than once weekly, your doctor might recommend an event recorder. This portable ECG device is intended to monitor your heart activity over a week to a few months. You wear it all day, but it records only at certain times for a few minutes at a time. You activate it by pushing a button when you have symptoms of a fast heart rate.
• Echocardiogram. This noninvasive exam creates a moving picture of your heart using sound waves. It can show blood flow and structure problems with your heart.