What is a Holter monitor?

• A. A blood pressure monitor
• B. A stethoscope
• C. A treadmill test
• D. A portable ECG monitor worn for hours to days to assess heart rhythm

Answer: (D)

A Holter monitor is a portable ECG device worn on the body for an extended period to continuously record the heart’s electrical activity. This allows doctors to detect intermittent or infrequent rhythm problems that might not show up during a single office ECG, by capturing data over hours to days. Typically, small leads attach to the chest and feed data to a small recorder you carry with you; you’ll usually keep a diary of symptoms and activities to help link what you feel with what the heart is doing. After the monitoring period, the data are analyzed to identify arrhythmias, pauses, or other rhythm disturbances and guide treatment.

It isn’t a blood pressure monitor, which only tracks pressure readings; it isn’t a stethoscope, which is used for listening to sounds at a single moment; and it isn’t a treadmill or exercise stress test, which evaluates heart function under physical exertion in a controlled setting.