Editing Holter monitor (section)

{{Short description|Portable device for cardiac monitoring}}
{{more citations needed|date=October 2020}}
{{Infobox medical intervention (new)|Name=Holter monitor|Speciality=[[Cardiology]], [[electrophysiology]]|image=HolterAFT1000.jpg|caption=3-lead Holter monitor|image_size=220}}

In [[medicine]], a '''Holter monitor''' (often simply '''Holter''') is a type of ambulatory [[electrocardiography]] device, a portable device for [[cardiac monitoring]] (the [[monitoring (medicine)|monitoring]] of the [[electrical conduction system of the heart|electrical activity of the cardiovascular system]]) for at least 24 hours.

The Holter's most common use is for monitoring ECG [[heart]] activity (electrocardiography or ECG). Its extended recording period is sometimes useful for observing occasional cardiac [[arrhythmia]]s which would be difficult to identify in a shorter period. For patients having more transient symptoms, a cardiac event monitor which can be worn for a month or more can be used.<ref>{{cite web|url=http://www.heart.org/HEARTORG/Conditions/HeartAttack/DiagnosingaHeartAttack/Holter-Monitor_UCM_446437_Article.jsp|title=Holter Monitor|work=www.heart.org|access-date=8 April 2018|archive-date=16 July 2018|archive-url=https://web.archive.org/web/20180716135958/http://www.heart.org/HEARTORG/Conditions/HeartAttack/DiagnosingaHeartAttack/Holter-Monitor_UCM_446437_Article.jsp|url-status=bot: unknown}}</ref>

When used to study the heart, much like standard electrocardiography, the Holter monitor records electrical signals from the heart via a series of [[electrode]]s attached to the chest. Electrodes are placed over bones to minimize artifacts from muscular activity. The number and position of electrodes varies by model, but most Holter monitors employ between three and eight. These electrodes are connected to a small piece of equipment that is attached to the patient's belt or hung around the neck, keeping a log of the heart's electrical activity throughout the recording period. A 12-lead Holter system is used when precise [[ECG]] information is required to analyse the exact origin of the abnormal signals.<ref>Herzschrittmacherther Elektrophysiol. 2013 Jun;24(2):92-96. {{doi|10.1007/s00399-013-0268-4}}. Epub 2013 Jun 19. 12-lead Holter electrocardiography. Review of the literature and clinical application update.  Su L1, Borov S, Zrenner B.</ref>