What is an Electrocardiogram (ECG or EKG)? Purpose, Procedure & Results

An electrocardiogram, commonly called an ECG or EKG, is a simple test that records the electrical activity of your heart. Think of it as taking a snapshot of how your heart beats and whether it's working properly. This painless test takes just a few minutes and can reveal important information about your heart's rhythm, rate, and overall health.

What is an Electrocardiogram (ECG or EKG)?

An ECG is a medical test that measures the electrical signals your heart produces with each heartbeat. Your heart creates these electrical impulses naturally to coordinate the pumping of blood through your body. The test records these signals on paper or a computer screen as wavy lines.

The terms ECG and EKG mean exactly the same thing. ECG comes from "electrocardiogram" in English, while EKG comes from the original German word "elektrokardiogramm." Both names are used interchangeably in medical settings, so don't worry if you hear different healthcare providers use different terms.

During the test, small sticky patches called electrodes are placed on your chest, arms, and legs. These electrodes act like tiny antennas that pick up your heart's electrical activity. The machine then translates these signals into a visual pattern that doctors can read and interpret.

Why is an Electrocardiogram (ECG or EKG) Done?

Doctors use ECGs to check how well your heart is working and to spot potential problems. This test can detect irregular heartbeats, heart attacks, and other heart conditions that might not cause obvious symptoms right away.

Your doctor might recommend an ECG if you're experiencing symptoms that could be related to your heart. These symptoms can feel concerning, but remember that many heart rhythm issues are treatable when caught early:

• Chest pain or discomfort
• Shortness of breath during normal activities
• Dizziness or feeling lightheaded
• Heart palpitations or feeling like your heart is racing
• Fainting spells or feeling like you might faint
• Unusual fatigue that doesn't improve with rest

ECGs are also used as routine screening tools during physical exams, especially if you have risk factors for heart disease. Your doctor might order one before surgery to make sure your heart can handle the procedure safely.

Sometimes, doctors use ECGs to monitor how well heart medications are working or to check for side effects from certain drugs. This helps ensure your treatment plan is working as intended and keeps you safe.

What is the Procedure for an ECG?

The ECG procedure is straightforward and completely painless. You'll lie comfortably on an examination table while a healthcare technician places small electrodes on your skin. The entire process typically takes about 5 to 10 minutes from start to finish.

Here's what happens during your ECG, step by step:

1. You'll be asked to undress from the waist up and put on a hospital gown
2. The technician will clean areas of your skin where electrodes will be placed
3. Small sticky patches (electrodes) are attached to your chest, arms, and legs
4. Wires from the electrodes connect to the ECG machine
5. You'll lie still and breathe normally while the machine records your heart's activity
6. The recording usually takes about 10 seconds to a few minutes
7. The electrodes are removed and you can get dressed

The most important thing during the test is to stay as still as possible and breathe normally. Movement can interfere with the recording, but don't worry if you need to cough or shift slightly. The technician will let you know if they need to repeat any part of the test.

How to Prepare for Your ECG

The good news is that ECGs require very little preparation on your part. You can eat and drink normally before the test, and you don't need to avoid any medications unless your doctor specifically tells you to.

There are a few simple things you can do to help ensure the best possible test results:

• Wear comfortable, loose-fitting clothing that's easy to remove from the waist up
• Avoid using lotions, oils, or powders on your chest and arms on the day of the test
• Let your doctor know about all medications you're taking, including over-the-counter drugs
• Remove jewelry from your neck, wrists, and ankles before the test
• Try to stay calm and relaxed, as anxiety can sometimes affect heart rhythm

If you have a lot of chest hair, the technician might need to shave small areas where the electrodes will be placed. This helps the electrodes stick properly and get a clear reading. Don't worry about this process - it's completely normal and necessary for accurate results.

How to Read Your ECG Results

Your ECG results will show several waves and lines that represent different parts of your heart's electrical activity. While these patterns might look complex, your doctor will explain what they mean in simple terms and whether anything needs attention.

A normal ECG typically shows a regular pattern with specific waves labeled P, QRS, and T. The P wave represents the electrical activity in your heart's upper chambers, the QRS complex shows activity in the lower chambers, and the T wave represents the heart muscle resetting for the next beat.

Your doctor will look at several key aspects of your ECG results:

• Heart rate - how fast or slow your heart is beating
• Heart rhythm - whether your heartbeat is regular or irregular
• Wave patterns - the shape and timing of electrical waves
• Intervals - the time between different parts of each heartbeat
• Axis - the direction of electrical flow through your heart

Normal ECG results mean your heart's electrical system is working properly. However, it's important to remember that a normal ECG doesn't rule out all heart problems, especially if symptoms come and go. Your doctor might recommend additional tests if needed.

What Do Abnormal ECG Results Mean?

Abnormal ECG results don't automatically mean you have serious heart disease. Many factors can cause changes in your ECG, including medications, electrolyte imbalances, or even your position during the test. Your doctor will consider your symptoms, medical history, and other factors when interpreting your results.

Some common abnormal findings include irregular heart rhythms, signs of previous heart attacks, or evidence that parts of your heart aren't getting enough oxygen. These findings help guide your doctor toward the most appropriate next steps for your care.

Here are some conditions that might show up on an ECG:

• Atrial fibrillation - an irregular, often rapid heart rate
• Heart block - delayed electrical signals between heart chambers
• Ischemia - reduced blood flow to parts of the heart muscle
• Left ventricular hypertrophy - thickening of the heart's main pumping chamber
• Electrolyte imbalances - changes in blood minerals that affect heart rhythm

If your ECG shows abnormalities, your doctor might recommend additional tests like an echocardiogram, stress test, or blood work. These tests provide more detailed information about your heart's structure and function.

What Are the Risk Factors for Abnormal ECG Results?

Several factors can increase your likelihood of having abnormal ECG results. Understanding these risk factors can help you and your doctor make informed decisions about your heart health and future testing needs.

Age is one of the most significant risk factors, as your heart's electrical system can change over time. However, many older adults have completely normal ECGs, so age alone doesn't determine your results.

Medical conditions that commonly affect ECG results include:

• High blood pressure - can cause changes in heart muscle thickness
• Diabetes - may damage blood vessels that supply the heart
• Heart disease - including previous heart attacks or coronary artery disease
• Thyroid disorders - can speed up or slow down heart rate
• Sleep apnea - affects oxygen levels and can strain the heart
• Kidney disease - can cause electrolyte imbalances

Lifestyle factors also play a role in your ECG results. Smoking, excessive alcohol consumption, and lack of physical activity can all affect your heart's electrical activity over time.

Certain medications can also influence your ECG, including some blood pressure medications, antidepressants, and antibiotics. Always tell your doctor about all medications and supplements you're taking.

Are There Any Risks or Side Effects from an ECG?

ECGs are extremely safe procedures with virtually no risks or side effects. The test only records your heart's electrical activity and doesn't send any electricity into your body. You won't feel any sensations during the test itself.

The only minor inconvenience you might experience is slight skin irritation where the electrodes were placed. This is usually very mild and goes away quickly. Some people with sensitive skin might notice small red marks that fade within a few hours.

If hair was shaved for electrode placement, you might feel slight irritation as it grows back. This is completely normal and temporary. Using a gentle moisturizer can help if your skin feels dry or irritated.

There are no restrictions on your activities after an ECG. You can return to your normal routine immediately, including driving, working, and exercising. The test won't affect your energy levels or how you feel.

When Should I See a Doctor About My ECG Results?

Your doctor will typically discuss your ECG results with you shortly after the test, either during the same visit or within a few days. If your results are normal, you might not need any follow-up beyond your regular checkups.

However, you should contact your doctor promptly if you develop new symptoms after your ECG, especially if you're waiting for results or have been told you need additional testing. Don't wait if you experience chest pain, severe shortness of breath, or fainting.

Signs that warrant immediate medical attention include:

• Severe chest pain or pressure
• Difficulty breathing or shortness of breath at rest
• Fainting or near-fainting episodes
• Rapid heart rate that doesn't slow down with rest
• Chest pain that spreads to your arm, jaw, or back

If you have questions about your ECG results or what they mean for your health, don't hesitate to ask your doctor. Understanding your results can help you make informed decisions about your care and give you peace of mind.