Question: What is a holter? Ramón (Barcelona).
Answer: The holter is a recorder connected to electrodes that, through stickers placed on the skin of the chest, detect the heartbeat. This device records the heartbeat during those 24 hours to assess whether the patient has any arrhythmia: that is, some alteration of the heart rhythm, both fast rhythms (tachycardias) and slow rhythms (bradycardias). It is a test that is not bothersome and has no risk.