A Holter monitor is a test that’s performed in order to understand the rhythms of the heart. A Holter monitor is worn by an individual, and consists of a battery pack, a small computer and electrode leads that the patient puts puts on.

After the 24-hour testing period, all of the heartbeats that are generated by the patient are captured by the Holter monitor, and the healthcare team downloads and interprets it. This test is used when there is a suspicion of the electrical sub-system of the heart that may cause rhythm problems; either rhythm problems that generate overly quick heart rhythms, or tachyarrhythmias, or overly slow rhythms such as bradyarrhythmias.