An electrocardiogram is a safe procedure. You'll have no risk of getting an electrical shock during the test because the electrodes placed on your body don't emit electricity. They only record the electrical activity of your heart.

You may have minor discomfort, similar to removing a bandage, when the electrodes are removed. Rarely, a reaction to the electrode adhesive may cause redness or swelling where the patches were placed.

A stress test may lead to irregular heart rhythms and, rarely, a heart attack. These effects are brought on by the exercise or medication, not the ECG itself.

A Holter monitor may cause some skin irritation if you don't move the electrodes each day.

An implantable loop recorder has a slight risk of infection because it involves a minor surgical procedure. And some people may experience a reaction to the device that causes inflammation.

Feb. 02, 2017
  1. Electrocardiogram. National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/ekg. Accessed Aug. 12, 2016.
  2. Stress testing. National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/stress/. Accessed Aug. 12, 2016.
  3. Goldman L, et al., eds. Electrocardiography. In: Goldman-Cecil Medicine. 25th ed. Philadelphia, Pa.: Saunders Elsevier; 2016. https://www.clinicalkey.com. Accessed Aug. 12, 2016.
  4. AskMayoExpert. Ambulatory heart rhythm monitoring. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2016.
  5. Barbara Woodward Lips Patient Education Center. Supraventricular tachycardia (SVT). Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2012.
  6. Chou R. Cardiac screening with electrocardiography, stress echocardiography, or myocardial perfusion imaging: Advice for high-value care from the American College of Physicians. Annals of Internal Medicine. 2015;162:438.
  7. Asirvatham SJ, et al. Electrocardiogram mapping-reentry: Final frontier? Circulation: Arrhythmia and Electrophysiology. 2014;7:760.
  8. Pfenninger JL, et al. Office electrocardiograms. In: Pfenninger and Fowler's Procedures for Primary Care. 3rd ed. Philadelphia, Pa.: Elsevier; 2011. https://www.clinicalkey.com. Accessed Aug. 12, 2016.
  9. Chen YH, et al. Soft, comfortable polymer dry electrodes for high quality ECG and EEG recording. Sensors. 2014;14:23758. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4299086/. Accessed Aug. 12, 2016.
  10. Nestler DM, et al. Impact of prehospital electrocardiogram protocol and immediate catheterization team activation for patients with ST-elevation-myocardial infarction. Circulation Cardiovascular Quality outcomes. 2011;4:640.
  11. Gibbons RJ, et al. Use of echocardiography in Olmsted County Outpatients with chest pain and normal resting electrocardiograms seen at Mayo Clinic Rochester. Mayo Clinic Proceedings. 2015;90:1492.
  12. What causes an arrhythmia? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/arr/causes. Accessed Oct. 7, 2016.
  13. Riggin EA. Allscripts EPSi. Mayo Clinic, Rochester, Minn. July 28, 2016.
  14. Riggin EA. Allscripts EPSi. Mayo Clinic, Rochester, Minn. Sept. 29, 2016.
  15. Murphy JG, et al., eds. Indications for invasive and noninvasive electrophysiologic testing. In: Mayo Clinic Cardiology: Concise Textbook. 4th ed. New York, N.Y.: Oxford University Press; 2013.
  16. Gerstenfeld EP, et al. Atrial fibrillation ablation: Indications, emerging techniques and follow-up. Progress in Cardiovascular Diseases. 2015;58:202.