Ambulatory electrocardiography (EKG or ECG)
Ambulatory electrocardiography (EKG or ECG) monitors the electrical activity of your heart while you go about your usual daily activities. Many heart problems occur only during certain activities, such as exercise, eating, emotional stress, or sleeping. A continuous 24-hour recording is much more likely to detect any abnormal heartbeats that occur during these activities.
The most common type of ambulatory monitoring is called Holter monitoring. The recording device of a Holter monitor is worn on a strap at your waist or over your shoulder. The electrical signals of the heart are picked up by two electrodes attached to your chest, which are connected to the recorder by wires. Holter monitoring provides a continuous 24- to 72-hour record of the electrical signals from your heart. While wearing the Holter monitor, you will also be asked to keep a journal of your activities and symptoms each day. After the monitoring period, your doctor will compare the timing of your activities and symptoms with the recorded heart pattern.
Many people have irregular heartbeats, or arrhythmias, periodically. The significance of irregular heartbeats depends on the type of pattern they produce, how frequently they occur, their duration, and whether they occur simultaneously with symptoms reported. Because arrhythmias can occur irregularly, it may be difficult to record one while you are in the office. A standard EKG monitors only 40 to 50 heartbeats during the brief period you are monitored by the machine. A Holter monitor records about 100,000 heartbeats in 24 hours and is much more likely to detect a problem.
Cardiac Event Monitor
Another kind of ambulatory EKG monitoring is called cardiac event monitoring. This can be used when symptoms of an abnormal heart rhythm occur infrequently. A cardiac event monitor can be used for a longer time than a Holter monitor and is more likely to record an abnormal heart rhythm that occurs less frequently. The information recorded by a cardiac event monitor is sent over the phone to our office.
Why is Holter/Event Recording Done?
- Detecting arrhythmias that occur intermittently or during certain activities.
- Evaluating symptoms of possible heart disease such as chest pain, palpitations, dizziness, or fainting.
- Detecting poor blood flow to your heart muscle (ischemia), which may indicate coronary artery disease (CAD).
- Monitoring the effectiveness of treatment, such as medication or a pacemaker for abnormal heart rhythms.
How To Prepare for the Event Monitor
It is a good idea to shower or bathe prior to using a Holter monitor, because you will not be able to do so during the recording period. Wear a loose-fitting blouse or shirt.
What to expect during Holter Monitoring
For Holter monitoring, a lightweight, battery-operated tape recorder (monitor) is worn on a strap over your shoulder or around your waist. The monitor is connected by wires to electrodes taped to your chest. The electrodes detect the electrical signals from your heart. A Holter monitor also has a clock linked to the recorder so you can write down what time it is when symptoms occur.
Our technician will fit you with the monitor and electrodes. Several areas on your chest may be shaved and cleaned, and then a small amount of electrode gel will be applied to those areas. Several electrode pads will then be attached to your chest, with thin wires connecting the electrodes to the monitor. You will also receive a booklet to write down any symptoms you have during the monitoring period, including the type of activity you were engaging in and the time your symptoms occurred.
You then resume normal daily activities while wearing the monitor. In the journal, write down the exact times when you exercise, climb stairs, eat, urinate, smoke cigarettes, sleep, get emotionally upset, take medications, or engage in other activities. If you have any symptoms of heart problems, i.e. dizziness, fainting, chest pain, or palpitations, push the event-marker button on the Holter monitor to mark it and write down the exact time and duration of the symptom. For example, you might write: “12:30 p.m. Ate lunch. 1:00 p.m. Argument with boss, had chest tightness for several minutes.” The accuracy and effectiveness of this test depends on how carefully you record your activities and symptoms and the times they occurred.
Overnight, try to stay on your back with the recorder carefully positioned at your side to ensure that the electrodes are not pulled off. If one of the electrodes or lead wires becomes loose, a light on the monitor will flash. Press on the center of each electrode to see if you can restore the contact. If one of the electrodes comes off and you have difficulty replacing it, call us.
At the end of the recording period (usually 24 hours), you will either return to the office to have the electrodes removed or, if you’ve been taught how, you may remove the electrodes yourself. A computer will analyze the recorded tape to provide information about your heart rate, the frequency of heart beats, and any abnormalities.
Cardiac Event Monitoring
The procedure for cardiac event monitoring depends on the type of monitor used. Electrodes will be attached to your chest in the same way as a Holter monitor, and you will be instructed to start the recorder when you have symptoms of a heart problem.
How a Cardiac Event Monitor Feels
The sites where the electrodes are on the chest may itch slightly during the recording, and the skin may become slightly irritated when the electrodes are removed. The recording unit is very lightweight, so carrying it usually is not problematic.
Risks Associated with a Cardiac Event Monitor
There is no risk associated with Holter or event monitoring. The electrodes placed on your skin only detect the electrical signals from your heart. No electricity is sent through your body, and there is no possibility of receiving an electric shock.
Results from Cardiac Event Monitoring
Results of ambulatory electrocardiography monitoring are interpreted by our cardiologists in New York. The results are generally available in a few days.