Clinical value of ambulatory rhythm monitoring.

(1) Ambulatory (Holter monitor) electrocardiography is currently one of the most important noninvasive cardiac diagnostic tests in our daily practice. (2) The primary purpose of Holter monitor electrocardiography is to diagnose various cardiac arrhythmias with accuracy, especially when the routine 12-lead electrocardiogram fails to record the arrhythmia because of its transient and episodic nature. (3) A precise etiology of a dizzy spell or a fainting episode can be confirmed by the Holter monitor ECG, when various symptoms are directly related to either tachyarrhythmias or bradyarrhythmias. (4) Another very important role of the Holter monitor ECG is to assess the efficacy of various antiarrhythmic agents, digitalis, and antianginal drugs. (5) Another purpose for obtaining the Holter monitor ECG is to document ischemic events by recognizing S-T segment and/or T wave abnormalities, especially at rest or during sleep. This is particularly valuable when the chest pain is atypical and when the exercise electrocardiogram is equivocal. Conversely, the patient's complaints may be totally unrelated to ischemic manifestations or any cardiac arrhythmias. (6) In addition, the status of artificial pacemaker function can be assessed by the Holter monitor ECG. (7) Many other clinical applications of the Holter monitor ECG have been described also.