Ambulatory Cardiac Monitoring

What is ambulatory cardiac monitoring?

If you have certain heart-related symptoms or a condition such as arrhythmia (abnormal heart beat), but a standard electrocardiogram (ECG/EKG) is unable to detect any abnormality, your doctor may recommend ambulatory cardiac monitoring. This refers to testing of the heart while you are "walking" (ambulatory) vs. "resting" during an office appointment.

Types of ambulatory cardiac monitoring

There are several different types of monitors that record heart rhythm and provide feedback information to your doctor. The monitors are similar but vary in terms of how long they record heart activity for and how and when the information gets transmitted to your doctor.

Holter monitor

A Holter monitor, also known as an ambulatory EKG, is a device used to track your heart's activity throughout a 24- or 48-hour period. The Holter device (named after the research laboratory where it was developed) has electrical wires that attach to electrodes, which are small, circular, conductive patches that adhere to the skin on your chest. The electrical signals that control heart rhythm are "picked up" by the monitor and recorded electronically.

While this information is being collected, you will also keep a journal of your activities, your energy level, and any symptoms you experience throughout your day. The doctor can later compare the information recorded by the Holter with information you have provided. With this assessment your doctor can evaluate your heart's behavior and make recommendations for further tests, treatments and therapies.

Cardiac event monitor

If you have infrequent arrhythmias (less than once a day), your doctor may recommend a cardiac event monitor (also called a cardiac event recorder) that allows you to record symptoms such as increased heart rate or feeling faint or dizzy, as they occur.

There are two types of cardiac event monitors: a looping memory monitor that allows you to program a recording for a short amount of time, and a symptom event monitor, which may be handheld or worn on your wrist. When you have a symptom, you hold it up to your chest and press the recording button to start recording.

The devices send your EKG reports by telephone to a receiving center or your doctor's office. Your doctor will be able to tell from your report whether certain medications are working, and when and why you are having the arrhythmias. If you have a pacemaker or implantable cardioverter defibrillator, the doctor will be able to determine how well it is working. If there is evidence of an emergency, you will be asked to go to the emergency room.

Mobile cardiac outpatient telemetry (MCOT)

Mobile cardiac outpatient telemetry, or MCOT, involves electrodes worn on the chest, similar to Holter monitoring, yet with continuous heartbeat monitoring throughout the day and up to 30 days.

Because there are a variety of symptoms associated with arrhythmias, such as fainting, dizziness, and heart palpitations, the MCOT device is able to pick up on these irregularities, often when you are not aware of them. You can also indicate when you are noticing these types of symptoms and prompt the device to record them. The device continually transmits this data to the monitoring center where round-the-clock technicians analyze every transmission and send the data to your doctor.

All forms of ambulatory cardiac monitoring are painless and none involve any kind of external electrical stimulation. After the recommended period of time has passed, your doctor will evaluate your results and talk with you about options and next steps.