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CHEST PAIN? CALL 911 — DO NOT USE DOD

If you have chest pain, pressure, tightness, palpitations with lightheadedness, sudden shortness of breath, jaw or arm pain, or any symptom of a possible cardiac event — call 911 or go to the nearest emergency room immediately. An EKG through DOD is not appropriate for emergency cardiac evaluation. DOD is strictly a non-emergency service.

Modality Education

EKG Education Guide

An electrocardiogram (EKG or ECG) is a non-invasive diagnostic test that records the electrical activity of the heart over a period of time. A standard 12-lead EKG uses electrodes placed on the chest, arms, and legs to detect the heart's electrical signals from multiple perspectives.

Educational content only. DOD reviews non-emergency EKG order requests only. For any possible cardiac emergency, call 911 immediately. DOD does not perform or interpret EKG tracings.

Quick Answer

An EKG records the heart's electrical activity using electrodes placed on the skin. It does not send electricity into the body and does not use ionizing radiation. A standard 12-lead EKG takes only a few minutes and is painless. EKG interpretation is performed by a licensed provider or cardiologist who reviews the waveform tracings. Provider orders may be required at outpatient diagnostic facilities. DOD can review non-emergency EKG order requests for eligible patients in supported states. For any cardiac symptoms — especially chest pain — call 911 immediately.

How an EKG Works

The heart generates electrical impulses that trigger each heartbeat. These electrical signals can be detected at the skin surface using electrodes. A standard 12-lead EKG places 10 electrodes (4 on the limbs, 6 on the chest) that together record electrical activity from 12 different "leads" or viewpoints. Each lead records the electrical activity from a different direction, providing a comprehensive electrical map of the heart's activity.

The EKG machine records these signals and produces a waveform tracing on paper or digital display. The waveform shows distinct components — P wave, QRS complex, T wave, and intervals between them — each corresponding to different phases of the cardiac cycle. According to MedlinePlus (NIH), an EKG is a safe, quick, and painless procedure that involves no radiation and no electrical current administered to the patient.

What an EKG May Provide Information About

A licensed provider interprets EKG results in the context of the patient's clinical presentation. EKG tracings may provide information about:

Heart rate and rhythm
Timing of electrical conduction through the heart chambers
Certain abnormalities in heart rhythm (arrhythmias)
Electrical conduction system abnormalities
Heart axis orientation
Signs that may be consistent with prior cardiac events (in appropriate clinical context)

EKG results require interpretation by a licensed provider. An EKG alone does not establish a diagnosis — it provides one piece of clinical information that providers use alongside history, physical examination, and other tests.

Frequently Asked Questions — EKG

Sources and Further Reading

Author: DOD Editorial Team
Last Updated: May 2026

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Educational content only. DOD does not perform or interpret EKG tracings. For any cardiac emergency, call 911 immediately. All clinical decisions should be made by qualified licensed healthcare providers.

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