Cardiology patient pages. Ambulatory electrocardiographic recording.

Abstract

Cardiac rhythm abnormalities are common. Although many arrhythmias are not harmful, some can cause symptoms and be a signal for potential cardiac arrest or stroke. Thus, the detection and quantification of these arrhythmias are important, especially for patients who have structural heart disease caused by an event such as a prior heart attack. Arrhythmias are frequently limited in duration and occurrence and cannot be detected during physical examination and routine electrocardiography (ECG) because these procedures permit only a few seconds of observation. To diagnose arrhythmias and to assess their relationship to patient symptoms, or to assess the effectiveness of an intervention to suppress them, longer periods of ECG recording are required while the patient is pursuing his or her normal routine. In this paper, we review the techniques and the clinical situations in which ambulatory ECG recordings are indicated. The most commonly used method of extended ECG recording is a Holter monitor (named for its inventor, Norman Holter) that uses a conventional tape recorder or solid-state storage system for acquiring ECG information that is later processed and displayed for physician review (Figure). Traditionally, these recordings are carried out for 24 to 48 hours via leads placed on the chest to yield 2 or 3 channels of ECG data. The patient is instructed to keep a diary of symptoms and to note the time on the Holter clock when the symptoms occur for later correlation to ECG abnormalities. For example, if the patient has a dizzy spell or rapid heart rhythm during the recording, the physician can determine if an arrhythmia, either fast or slow, was or …