Ambulatory Electrocardiographic monitoring or Holter monitoring is a technique used to record a continuous electrocardiogram (ECG) for 24 to 48 hours. The electrocardiogram is recorded on a tape cassette or digital recording device. Holter monitoring is basically used for two purposes: (1) To record and evaluate the heart rhythm and any abnormality that might occur; (2) To look for Electrocardiographic changes associated with the occasional imbalance of blood flow to the heart muscle through the coronary arteries (ischemia).
What happens during the procedure?
In the doctor's office, the hospital, or clinic you will be asked to remove your clothes down to the waist. You will then have sticky electrodes properly positioned and secured with adhesive. Men will have portions of their chest hair shaved so that the electrodes will stick better. The electrodes are attached to a small, battery-powered tape recorder. The recorder is carried by means of a belt or shoulder strap. You will be given a diary to record your activities or symptoms for the next 24 or 48 hours. The technician will show you how to operate the device, particularly how to signal an event that you will also write down on your diary. Upon your return to the medical facility, the electrodes will be removed and the tape cassette and diary reviewed for any abnormalities. You may be asked to remove the unit yourself at home. The technician will instruct you about this. You may be asked to bring the unit back to the office or hospital or to mail it back in a mailer provided. The procedure is very safe, although sometimes the electrode attachments cause minor skin irritation. Occasional patients are quite sensitive to the gel used in the electrodes and a blistering of the skin may occur. If you have painful burning under the electrodes or have previously had this difficulty, please let the staff know.
What happens after the procedure?
After your doctor reviews the recordings, you will be told of the results at your next visit or sooner, if necessary. Sometimes, more than one recording may be needed to detect certain rhythm abnormalities, especially if they occur infrequently. When the monitor is being used to evaluate the effectiveness of medications to control certain heart rhythms or to improve the blood flow to your heart, more than one recording may be necessary.