Electrocardiogram (ECG or EKG): References

Electrocardiogram (ECG or EKG). American Heart Association. https://www.heart.org/en/health-topics/heart-attack/diagnosing-a-heart-attack/electrocardiogram-ecg-or-ekg. Updated July 31, 2015. Accessed December 2019.

US Department of Health and Human Services. National Institutes of Health. National Heart, Lung, and Blood Institute. Electrocardiogram. https://www.nhlbi.nih.gov/health-topics/electrocardiogram. Accessed December 2019.