What is a Holter monitor?
A Holter monitor is a type of portable electrocardiogram (EKG or ECG) that continuously monitors your heart’s activity over a 24- or 48-hour period. The small device helps detect symptoms that come and go and may not show up on an ECG you have at your cardiologist’s office.
Holter monitors are one type of heart monitor (also called an event monitor) that your cardiologist can use to measure symptoms outside the office. Holter monitors can help if your symptoms are frequent. If they are not, a Holter monitor might miss them, and your provider may recommend another device that you wear for a longer period.
Why would I need a Holter monitor?
A regular ECG shows your heart’s activity at a single moment during the test. However, heart symptoms and irregular rhythms can come and go. That’s why your doctor may recommend monitoring your heartbeat over a longer period while you go about your normal daily activities.
A Holter monitor may be recommended if:
- You experience fast, slow or irregular heartbeats, also known as arrhythmias
- Your doctor needs to check if your medications are working effectively
- You have symptoms such as dizziness, fainting or a sensation that your heart is racing or skipping beats
- There’s a need to determine if your heart is receiving enough oxygen to function properly
- Your care team wants to monitor your heart rate after you have a device, such as a pacemaker, implanted
- There’s a need to monitor your heart’s activity after a heart attack
Preparing for a Holter monitor test
A Holter monitor is about the size of a deck of cards. You wear it on a belt, around your neck or with a shoulder strap, and it connects to your chest through electrodes attached with small sticky pads.
Before your appointment, your technician may ask you to avoid applying lotions, oils or other skin care products, which may interfere with the sticky pads. You should also let the technician know if you have any allergies to tapes or adhesives.
If you have hair on your chest, the technician will shave the area before attaching the electrodes.
What to expect with a Holter monitor test
During a Holter monitor test
Typically, a Holter monitor is worn for 24 to 48 hours. It will record an ECG continuously throughout that period. You will likely be asked to document your activities and symptoms in a diary while you’re wearing it so your cardiologist can compare any irregular heartbeats or symptoms picked up on the ECG with what you were doing at the time.
Your technician will give you tips for recording your activities when you receive the monitor, but here are some general tips:
- Log symptoms such as chest pain, heart fluttering or skipping a beat, dizziness and shortness of breath. Write down the time you feel symptoms and whether you were engaged in an activity.
- Note all your activities, including when you take medications, drive or sleep, and at what time those activities occur.
Tips for wearing a Holter monitor
Your technician will explain how the device works and give you instructions to follow while wearing it. In general, you will need to:
- Avoid sources of electricity: These might interfere with the monitor’s recordings, such as electric blankets, magnets, metal detectors and high-voltage areas.
- Continue your daily activities: Do all the things you normally do, including exercise, if your cardiologist asks you to, so the monitor records symptoms when they usually occur.
- Keep the monitor dry: You won’t be able to take a shower, but you may be able to take a sponge bath.
- Keep the monitor close to your body: Have it near you even while sleeping. Sleeping on your back may help keep the device close and make you feel more comfortable.
You also can’t have any X-rays while wearing the monitor.
Call your cardiologist or technician if you experience any of the following during your study:
- An electrode that falls off or makes noise
- Skin irritation or an allergic reaction caused by the adhesive patches
Understanding your Holter monitor results
Your healthcare provider will review the results of your Holter monitor test and go over them with you. The information from the test can help show if you have a heart condition and whether your current heart medications are working as they should.
If your test is “normal,” your doctor did not see any irregular heartbeats or significant changes in the ECG patterns over the study period. Abnormal results suggest that you may have an arrhythmia, such as atrial fibrillation. Your cardiologist may schedule a follow-up visit to discuss additional testing options and potential treatments.
Find a location near you
Our cardiac technicians work with cardiologists at locations across Central and North Texas. We’ll work to arrange your appointments and follow-up care at a location convenient to you.

5701 Bryant Irvin Rd Ste 302, Fort Worth, TX, 76132
5701 Bryant Irvin Rd Ste 302, Fort Worth, TX, 76132
Not accepting walk-ins

621 N Hall St Ste 500, Dallas, TX, 75226
621 N Hall St Ste 500, Dallas, TX, 75226
Not accepting walk-ins

4400 Interstate 30 W Ste 300, Greenville, TX, 75402
4400 Interstate 30 W Ste 300, Greenville, TX, 75402
Not accepting walk-ins

1575 Interstate 30 , Mesquite, TX, 75150
1575 Interstate 30 , Mesquite, TX, 75150
Not accepting walk-ins

4431 E US Hwy 287 , Midlothian, TX, 76065
4431 E US Hwy 287 , Midlothian, TX, 76065
Not accepting walk-ins

9101 N Central Expy Ste 300C, Dallas, TX, 75231
9101 N Central Expy Ste 300C, Dallas, TX, 75231
Not accepting walk-ins

301 E Ovilla Rd Ste 100, Red Oak, TX, 75154
301 E Ovilla Rd Ste 100, Red Oak, TX, 75154
Not accepting walk-ins

2360 N Interstate 35E Ste 110, Waxahachie, TX, 75165
2360 N Interstate 35E Ste 110, Waxahachie, TX, 75165
Not accepting walk-ins

1307 8th Ave Ste 406, Fort Worth, TX, 76104
1307 8th Ave Ste 406, Fort Worth, TX, 76104
Not accepting walk-ins

5308 N Galloway Ave Ste 201, Mesquite, TX, 75150
5308 N Galloway Ave Ste 201, Mesquite, TX, 75150
Not accepting walk-ins

6705 Heritage Pkwy Ste 202, Rockwall, TX, 75087
6705 Heritage Pkwy Ste 202, Rockwall, TX, 75087
Not accepting walk-ins

2608 Brockton Dr , Austin, TX, 78758
2608 Brockton Dr , Austin, TX, 78758
Not accepting walk-ins

10815 Ranch Rd 2222 , Austin, TX, 78730
10815 Ranch Rd 2222 , Austin, TX, 78730
Not accepting walk-ins

5330 Overpass Rd Ste 100, Buda, TX, 78610
5330 Overpass Rd Ste 100, Buda, TX, 78610
Not accepting walk-ins

910 E Whitestone Blvd , Cedar Park, TX, 78613
910 E Whitestone Blvd , Cedar Park, TX, 78613
Not accepting walk-ins

4945 Williams Dr , Georgetown, TX, 78633
4945 Williams Dr , Georgetown, TX, 78633
Not accepting walk-ins

3108 Ranch Rd 620 S , Lakeway, TX, 78738
3108 Ranch Rd 620 S , Lakeway, TX, 78738
Not accepting walk-ins

706 Ave G , Marble Falls, TX, 78654
706 Ave G , Marble Falls, TX, 78654
Not accepting walk-ins

2600 E Pflugerville Pkwy Bldg 1, Ste 200, Pflugerville, TX, 78660
2600 E Pflugerville Pkwy Bldg 1, Ste 200, Pflugerville, TX, 78660
Not accepting walk-ins

300A University Blvd , Round Rock, TX, 78665
300A University Blvd , Round Rock, TX, 78665
Not accepting walk-ins

403 Mallard Ln , Taylor, TX, 76574
403 Mallard Ln , Taylor, TX, 76574
Not accepting walk-ins

3333 Colorado Blvd , Denton, TX, 76210
3333 Colorado Blvd , Denton, TX, 76210
Not accepting walk-ins

201 N Interstate 35 Ste 140, Gainesville, TX, 76240
201 N Interstate 35 Ste 140, Gainesville, TX, 76240
Not accepting walk-ins

763 E US Hwy 80 Ste 240, Forney, TX, 75126
763 E US Hwy 80 Ste 240, Forney, TX, 75126
Not accepting walk-ins

7801 Lakeview Pkwy Ste 100, Rowlett, TX, 75088
7801 Lakeview Pkwy Ste 100, Rowlett, TX, 75088
Not accepting walk-ins

6257 FM 2642 Blvd Ste 100, Royse City, TX, 75189
6257 FM 2642 Blvd Ste 100, Royse City, TX, 75189
Not accepting walk-ins

3341 Unicorn Lake Blvd , Denton, TX, 76210
3341 Unicorn Lake Blvd , Denton, TX, 76210
Not accepting walk-ins

4716 Alliance Blvd Pavilion II, Ste 300, Plano, TX, 75093
4716 Alliance Blvd Pavilion II, Ste 300, Plano, TX, 75093
Not accepting walk-ins