What is a Holter monitor?
The Holter monitor is a type of electrocardiogram (ECG) used to record an ECG tracing of the heart continuously for 24 hours or longer. A standard or "resting" ECG is one of the simplest and fastest procedures used to evaluate the heart. Electrodes (small, plastic patches that stick to the skin) are placed at certain locations on the chest and abdomen. When the electrodes are connected to an ECG machine by wires, the electrical activity of the heart is measured, recorded, and printed. No electricity is sent into the body.
Natural electrical impulses coordinate contractions of the different parts of the heart to keep blood flowing the way it should. An ECG records these impulses to show how fast the heart is beating, the rhythm of the heart beats (steady or irregular), and the strength and timing of the electrical impulses as they move through the different parts of the heart. Changes in an ECG can be a sign of many heart-related conditions.
When symptoms, such as dizziness, fainting, low blood pressure, ongoing fatigue (tiredness), and palpitations, continue to occur and a resting ECG doesn’t show a clear cause, your health care provider may request an ECG tracing to be recorded over a long period, using the Holter monitor. You wear the same kind of ECG electrode patches on your chest, and the electrodes are connected by wires to a small, portable recording device.
Certain arrhythmias (abnormal heart rhythms) may occur only now and then, or may occur only under certain conditions, such as stress or activity. Arrhythmias of this type are hard to record on an ECG tracing that only runs for a few minutes. Because of this, the health care provider might request a Holter monitor to get a better chance of capturing any abnormal heartbeats or rhythms that may be causing the symptoms. Some Holter monitors also have an event monitor feature that you activate when you notice symptoms.
You will get instructions on how long you will need to wear the monitor (usually 24 to 48 hours), how to keep a diary of your activities and symptoms during the test, and personal care and activity instructions, which include keeping the device dry while you are wearing it.
What are the risks of a Holter monitor?
The Holter monitor is an easy way to assess the heart’s function. Risks associated with the Holter monitor are rare.
It can be hard to keep the electrodes stuck to your skin, and extra tape may be needed. It may be uncomfortable when the sticky electrodes and tape are taken off. Prolonged application of the adhesive electrode patches may cause tissue breakdown or skin irritation at the application site.
There may be other risks depending on your specific medical condition. Be sure to discuss any concerns with your healthcare provider prior to wearing the monitor.
Certain factors or conditions may interfere with or affect the results of the Holter monitor reading. These include, but are not limited to:
- Close proximity to magnets, metal detectors, high-voltage electrical wires, and electrical appliances such as shavers, toothbrushes, and microwave ovens. Cell phones and MP3 players can also interfere with the signals and should be kept at least 6 inches away from the monitor box.
- Smoking or using other forms of tobacco
- Certain medications
- Excessive sweating, which may cause the leads to loosen or come off
What happens after a Holter monitor?
You should be able to go back your normal diet and activities, unless your healthcare provider instructs you differently.
Generally, there is no special care following a Holter monitor recording.
Notify your healthcare provider if you develop any signs or symptoms you had prior to the recording (for example, chest pain, shortness of breath, dizziness, or fainting).
Your healthcare provider may give you additional or alternate instructions after the procedure, depending on your particular situation.