Holter monitor (24h)

Ambulatory electrocardiography; Electrocardiography - ambulatory; Atrial fibrillation - Holter; Flutter - Holter; Tachycardia - Holter; Abnormal heart rhythm - Holter; Arrythmia - Holter

A Holter monitor is a machine that continuously records the heart’s rhythms. The monitor is worn for 24 to 48 hours during normal activity.

Holter heart monitor

During a heart Holter monitor study, the patient wears a monitor that records electrical activity of their heart (similarly to the recording of an electrocardiogram). This usually occurs for 24 hours, while at the same time the patient also records a diary of their activity. Health care providers then analyze the recording, tabulate a report of the heart’s activity, and correlate irregular heart activity with the entries of the patient’s diary.

Heart, section through the middle

The interior of the heart is composed of valves, chambers, and associated vessels.

Heart, front view

The external structures of the heart include the ventricles, atria, arteries and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide. The vessels colored red indicate the transport of blood with relatively high content of oxygen and low content of carbon dioxide.

Normal heart rhythm

An electrocardiogram (ECG) test measures the electrical activity of the heart. A normal resting heart rate is 60 to 100 beats per minute.

Conduction system of the heart

The intrinsic conduction system sets the basic rhythm of the beating heart by generating impulses which stimulate the heart to contract.

How the Test is Performed

How to Prepare for the Test

How the Test will Feel

Why the Test is Performed

Normal Results

What Abnormal Results Mean

Risks