A Holter monitor is a continuous recording of a patient's EKG for 24 hours. It helps the physician correlate symptoms of dizziness, irregular heart rhythms (palpitations), or blackouts. It starts with applying EKG electrodes to the chest. Thin wires connect the electrodes to a small tape recorder, which is secured to the patient's belt or slung over the shoulder and neck. The recorder is worn for 24 hours and the patient is encouraged to continue his or her daily activities. A diary or log is provided so that the patient can record activity and symptoms. The Holter monitor has an internal clock which stamps the time on the EKG strips. These can be used to correlate the heart rhythm with symptoms or complaints. After 24 hours, the Holter monitor is returned to the laboratory for analysis.