BACK TOTOP Browse A-ZSearchBrowse A-ZABCDEFGHIJKLMNOPQRSTUVWXYZ0-9 E-mail FormEmail ResultsName:Email address:Recipients Name:Recipients address:Message: Print-FriendlyBookmarksbookmarks-menuElectrocardiogramECG; EKGAn electrocardiogram (ECG) is a test that records the electrical activity of the heart.Related video goes here for no-HTML5 browsers How the Test is Performed You will be asked to lie down. The health care provider will clean several areas on your arms, legs, and chest, and then will attach small patches called electrodes to those areas. It may be necessary to shave or clip some hair so the patches stick to the skin. The number of patches used may vary.The patches are connected by wires to a machine that turns the heart's electrical signals into wavy lines, which are often printed on paper. The doctor reviews the test results.You will need to remain still during the procedure. The provider may also ask you to hold your breath for a few seconds as the test is being done. It is important to be relaxed and warm during an ECG recording because any movement, including shivering, can alter the results. Sometimes this test is done while you are exercising or under light stress to look for changes in the heart. This type of ECG is often called a stress test. How to Prepare for the Test Make sure your provider knows about all the medicines you are taking. Some drugs can interfere with test results.Do not exercise or drink cold water immediately before an ECG because these actions may cause false results. How the Test will Feel An ECG is painless. No electricity is sent through the body. The electrodes may feel cold when first applied. In rare cases, some people may develop a rash or irritation where the patches were placed. Why the Test is Performed An ECG is used to measure:Any damage to the heart How fast your heart is beating and whether it is beating normally The effects of drugs or devices used to control the heart (such as a pacemaker) PacemakerA pacemaker is a small, battery-operated device. This device senses when your heart is beating too slowly. It sends a signal to your heart that mak...ImageRead Article Now Book Mark Article The size and position of your heart chambers An ECG is often the first test done to determine whether a person has heart disease. Your provider may order this test if:Heart diseaseCoronary heart disease is a narrowing of the blood vessels that supply blood and oxygen to the heart. Coronary heart disease (CHD) is also called co...ImageRead Article Now Book Mark Article You have chest pain or palpitations Chest painChest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.ImageRead Article Now Book Mark Article PalpitationsPalpitations are feelings or sensations that your heart is pounding or racing. They can be felt in your chest, throat, or neck. You may:Have an unpl...ImageRead Article Now Book Mark Article You are scheduled for surgery You have had heart problems in the past You have a strong history of heart disease in the family Normal Results Normal test results most often include:Heart rate: 60 to 100 beats per minute Heart rhythm: Consistent and even What Abnormal Results Mean Abnormal ECG results may be a sign of:Damage or changes to the heart muscle Changes in the amount of the electrolytes (such as potassium and calcium) in the blood Congenital heart defect Enlargement of the heart Enlargement of the heartCardiomyopathy is disease in which the heart muscle becomes weakened, stretched, or has another structural problem. Dilated cardiomyopathy is a condi...ImageRead Article Now Book Mark Article Fluid or swelling in the sac around the heart Inflammation of the heart (myocarditis) Inflammation of the heartPericarditis is a condition in which the sac-like covering around the heart (pericardium) becomes inflamed.ImageRead Article Now Book Mark Article Past or current heart attack Heart attackMost heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. ...ImageRead Article Now Book Mark Article Poor blood supply to the heart arteries Abnormal heart rhythms (arrhythmias) ArrhythmiasAn arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregul...ImageRead Article Now Book Mark Article Some heart problems that can lead to changes on an ECG test include:Atrial fibrillation/flutter Atrial fibrillation/flutterAtrial fibrillation (Afib) and atrial flutter are common types of abnormal heart rhythms (arrhythmias) which affect the upper chambers (atria) of the...ImageRead Article Now Book Mark Article Heart attack Heart failure Heart failureHeart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...ImageRead Article Now Book Mark Article Multifocal atrial tachycardia Multifocal atrial tachycardiaMultifocal atrial tachycardia (MAT) is a rapid heart rate. It occurs when too many signals (electrical impulses) are sent from the upper heart (atri...ImageRead Article Now Book Mark Article Paroxysmal supraventricular tachycardia Paroxysmal supraventricular tachycardiaParoxysmal supraventricular tachycardia (PSVT) is episodes of a rapid heart rate that start in a part of the heart above the ventricles. "Paroxysmal...ImageRead Article Now Book Mark Article Sick sinus syndrome Sick sinus syndromeNormally, the heartbeat starts in an area in the top chambers of the heart (atria). This area is the heart's pacemaker. It is called the sinoatrial...ImageRead Article Now Book Mark Article Wolff-Parkinson-White syndromeWolff-Parkinson-White syndromeWolff-Parkinson-White (WPW) syndrome is a condition in which there is an extra electrical pathway in the heart that leads to periods of rapid heart r...ImageRead Article Now Book Mark Article Risks There are no risks. Considerations The accuracy of the ECG depends on the condition being tested. A heart problem may not always show up on the ECG. Some heart conditions never produce any specific ECG changes.Open ReferencesReferencesBrady WJ, Harrigan RA, Chan TC. Basic electrocardiographic techniques. In: Roberts JR, Custalow CB, Thomsen TW, eds. Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 14.Ganz L, Link MS. Electrocardiography. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 48.Mirvis DM, Goldberger AL. Electrocardiography. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 14. AllVideoImagesTogElectrocardiogramAnimation Related video goes here for no-HTML5 browsersElectrocardiogram - Animation If your heart has been beating too fast, or you've been having chest pain, both you and your doctor will want to find out what's causing the problem so you can get it treated. One way to diagnose heart problems is with a test of the heart's electrical activity, called an electrocardiogram or ECG, or EKG for short. Your heart is controlled by an electrical system, much like the electricity that powers the lights and appliances in your home. Electrical signals make your heart contract so that it can pump blood out to your body. Heart disease, abnormal heart rhythms, and other heart problems can affect those signals. Using an ECG, your doctor can identify problems in your heart's electrical system and diagnose heart disease. So, how is an ECG done? First you'll lie down on a table. You'll have to lie very still while the test is done. Small patches, called electrodes, will be attached to several places on your arms, legs, and chest. The patches won't hurt, but some of the hair in those areas may be shaved so the patches will stick to your skin. The patches are then attached to a machine. You'll notice that when the machine is turned on, it produces wavy lines on a piece of paper. Those lines represent the electrical signals coming from your heart. If the test is normal, it should show that your heart is beating at an even rate of 60 to 100 beats per minute. Many different heart conditions can show up on an ECG, including a fast, slow, or abnormal heart rhythm, a heart defect, coronary artery disease, heart valve disease, or an enlarged heart. An abnormal ECG may also be a sign that you've had a heart attack in the past, or that you're at risk for one in the near future. If you're healthy and you don't have any family or personal history of heart disease, you don't need to have an ECG on a regular basis. But if you are having heart problems, your doctor may recommend getting this test. An ECG is pretty accurate at diagnosing many types of heart disease, although it doesn't always pick up every heart problem. You may have a perfectly normal ECG, yet still have a heart condition. If your test is normal but your doctor suspects that you have a heart problem, he may recommend that you have another ECG, or a different type of test to find out for sure.Electrocardiogram (ECG) test overviewAnimation Related video goes here for no-HTML5 browsersElectrocardiogram (ECG) test overview - Animation Action potentials generated by heart cells produce weak electrical currents that spread throughout the body. These currents can be detected at the surface of the body and amplified using an instrument known as an electrocardiograph. The graphic recording produced by an electrocardiograph of the heart electric activity is called an electrocardiogram, or ECG.ECG - illustration The electrocardiogram (ECG) is used extensively in the diagnosis of heart disease, from congenital heart disease in infants to myocardial infarction and myocarditis in adults. Several different types of electrocardiogram exist.ECGillustrationAtrioventricular block - ECG tracing - illustration This picture shows an ECG (electrocardiogram, EKG) of a person with an abnormal rhythm (arrhythmia) called an atrioventricular (AV) block. P waves show that the top of the heart received electrical activity. Each P wave is usually followed by the tall (QRS) waves. QRS waves reflect the electrical activity that causes the heart to contract. When a P wave is present and not followed by a QRS wave (and heart contraction), there is an atrioventricular block, and a very slow pulse (bradycardia).Atrioventricular block - ECG tracingillustrationHigh blood pressure tests - illustration Routine lab tests are recommended before beginning treatment of high blood pressure to determine organ or tissue damage or other risk factors. These lab tests include urinalysis, blood cell count, blood chemistry (potassium, sodium, creatinine, fasting glucose, total cholesterol and HDL cholesterol), and an ECG (electrocardiogram). Additional tests may be recommended based on your condition.High blood pressure testsillustrationElectrocardiogram (ECG) - illustration An electrocardiogram is a test that measures the electrical activity of the heart. This includes the rate and regularity of beats as well as the size and position of the chambers, any damage to the heart, and effects of drugs or devices to regulate the heart.Electrocardiogram (ECG)illustrationECG electrode placement - illustration An ECG is very useful in determining whether a person has heart disease. During an ECG electrodes are affixed to each arm and leg and to the chest. ECG electrode placementillustrationElectrocardiogramAnimation Related video goes here for no-HTML5 browsersElectrocardiogram - Animation If your heart has been beating too fast, or you've been having chest pain, both you and your doctor will want to find out what's causing the problem so you can get it treated. One way to diagnose heart problems is with a test of the heart's electrical activity, called an electrocardiogram or ECG, or EKG for short. Your heart is controlled by an electrical system, much like the electricity that powers the lights and appliances in your home. Electrical signals make your heart contract so that it can pump blood out to your body. Heart disease, abnormal heart rhythms, and other heart problems can affect those signals. Using an ECG, your doctor can identify problems in your heart's electrical system and diagnose heart disease. So, how is an ECG done? First you'll lie down on a table. You'll have to lie very still while the test is done. Small patches, called electrodes, will be attached to several places on your arms, legs, and chest. The patches won't hurt, but some of the hair in those areas may be shaved so the patches will stick to your skin. The patches are then attached to a machine. You'll notice that when the machine is turned on, it produces wavy lines on a piece of paper. Those lines represent the electrical signals coming from your heart. If the test is normal, it should show that your heart is beating at an even rate of 60 to 100 beats per minute. Many different heart conditions can show up on an ECG, including a fast, slow, or abnormal heart rhythm, a heart defect, coronary artery disease, heart valve disease, or an enlarged heart. An abnormal ECG may also be a sign that you've had a heart attack in the past, or that you're at risk for one in the near future. If you're healthy and you don't have any family or personal history of heart disease, you don't need to have an ECG on a regular basis. But if you are having heart problems, your doctor may recommend getting this test. An ECG is pretty accurate at diagnosing many types of heart disease, although it doesn't always pick up every heart problem. You may have a perfectly normal ECG, yet still have a heart condition. If your test is normal but your doctor suspects that you have a heart problem, he may recommend that you have another ECG, or a different type of test to find out for sure.Electrocardiogram (ECG) test overviewAnimation Related video goes here for no-HTML5 browsersElectrocardiogram (ECG) test overview - Animation Action potentials generated by heart cells produce weak electrical currents that spread throughout the body. These currents can be detected at the surface of the body and amplified using an instrument known as an electrocardiograph. The graphic recording produced by an electrocardiograph of the heart electric activity is called an electrocardiogram, or ECG.ECG - illustration The electrocardiogram (ECG) is used extensively in the diagnosis of heart disease, from congenital heart disease in infants to myocardial infarction and myocarditis in adults. Several different types of electrocardiogram exist.ECGillustrationAtrioventricular block - ECG tracing - illustration This picture shows an ECG (electrocardiogram, EKG) of a person with an abnormal rhythm (arrhythmia) called an atrioventricular (AV) block. P waves show that the top of the heart received electrical activity. Each P wave is usually followed by the tall (QRS) waves. QRS waves reflect the electrical activity that causes the heart to contract. When a P wave is present and not followed by a QRS wave (and heart contraction), there is an atrioventricular block, and a very slow pulse (bradycardia).Atrioventricular block - ECG tracingillustrationHigh blood pressure tests - illustration Routine lab tests are recommended before beginning treatment of high blood pressure to determine organ or tissue damage or other risk factors. These lab tests include urinalysis, blood cell count, blood chemistry (potassium, sodium, creatinine, fasting glucose, total cholesterol and HDL cholesterol), and an ECG (electrocardiogram). Additional tests may be recommended based on your condition.High blood pressure testsillustrationElectrocardiogram (ECG) - illustration An electrocardiogram is a test that measures the electrical activity of the heart. This includes the rate and regularity of beats as well as the size and position of the chambers, any damage to the heart, and effects of drugs or devices to regulate the heart.Electrocardiogram (ECG)illustrationECG electrode placement - illustration An ECG is very useful in determining whether a person has heart disease. During an ECG electrodes are affixed to each arm and leg and to the chest. ECG electrode placementillustration Tests for Electrocardiogram ElectrocardiogramRelated Information Exercise stress test(Medical Test)Holter monitor (24h)(Medical Test)Chest pain(Symptoms)Heart palpitations(Symptoms)Dilated cardiomyopathy(Condition)Arrhythmias(Condition)Pulse - bounding(Symptoms)Ectopic heartbeat(Condition)Stable angina(Condition)Pericarditis(Condition)Coronary artery disease - InDepth(In-Depth)Heart attack and acute coronary syndrome - InDepth(In-Depth)Eating disorders - InDepth(In-Depth) Review Date: 5/8/2022 Reviewed By: Michael A. Chen, MD, PhD, Associate Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language. © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited. © 1997- All rights reserved. A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.Content is best viewed in IE9 or above, Firefox and Google Chrome browser.
ElectrocardiogramECG; EKGAn electrocardiogram (ECG) is a test that records the electrical activity of the heart.Related video goes here for no-HTML5 browsers How the Test is Performed You will be asked to lie down. The health care provider will clean several areas on your arms, legs, and chest, and then will attach small patches called electrodes to those areas. It may be necessary to shave or clip some hair so the patches stick to the skin. The number of patches used may vary.The patches are connected by wires to a machine that turns the heart's electrical signals into wavy lines, which are often printed on paper. The doctor reviews the test results.You will need to remain still during the procedure. The provider may also ask you to hold your breath for a few seconds as the test is being done. It is important to be relaxed and warm during an ECG recording because any movement, including shivering, can alter the results. Sometimes this test is done while you are exercising or under light stress to look for changes in the heart. This type of ECG is often called a stress test. How to Prepare for the Test Make sure your provider knows about all the medicines you are taking. Some drugs can interfere with test results.Do not exercise or drink cold water immediately before an ECG because these actions may cause false results. How the Test will Feel An ECG is painless. No electricity is sent through the body. The electrodes may feel cold when first applied. In rare cases, some people may develop a rash or irritation where the patches were placed. Why the Test is Performed An ECG is used to measure:Any damage to the heart How fast your heart is beating and whether it is beating normally The effects of drugs or devices used to control the heart (such as a pacemaker) PacemakerA pacemaker is a small, battery-operated device. This device senses when your heart is beating too slowly. It sends a signal to your heart that mak...ImageRead Article Now Book Mark Article The size and position of your heart chambers An ECG is often the first test done to determine whether a person has heart disease. Your provider may order this test if:Heart diseaseCoronary heart disease is a narrowing of the blood vessels that supply blood and oxygen to the heart. Coronary heart disease (CHD) is also called co...ImageRead Article Now Book Mark Article You have chest pain or palpitations Chest painChest pain is discomfort or pain that you feel anywhere along the front of your body between your neck and upper abdomen.ImageRead Article Now Book Mark Article PalpitationsPalpitations are feelings or sensations that your heart is pounding or racing. They can be felt in your chest, throat, or neck. You may:Have an unpl...ImageRead Article Now Book Mark Article You are scheduled for surgery You have had heart problems in the past You have a strong history of heart disease in the family Normal Results Normal test results most often include:Heart rate: 60 to 100 beats per minute Heart rhythm: Consistent and even What Abnormal Results Mean Abnormal ECG results may be a sign of:Damage or changes to the heart muscle Changes in the amount of the electrolytes (such as potassium and calcium) in the blood Congenital heart defect Enlargement of the heart Enlargement of the heartCardiomyopathy is disease in which the heart muscle becomes weakened, stretched, or has another structural problem. Dilated cardiomyopathy is a condi...ImageRead Article Now Book Mark Article Fluid or swelling in the sac around the heart Inflammation of the heart (myocarditis) Inflammation of the heartPericarditis is a condition in which the sac-like covering around the heart (pericardium) becomes inflamed.ImageRead Article Now Book Mark Article Past or current heart attack Heart attackMost heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. ...ImageRead Article Now Book Mark Article Poor blood supply to the heart arteries Abnormal heart rhythms (arrhythmias) ArrhythmiasAn arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregul...ImageRead Article Now Book Mark Article Some heart problems that can lead to changes on an ECG test include:Atrial fibrillation/flutter Atrial fibrillation/flutterAtrial fibrillation (Afib) and atrial flutter are common types of abnormal heart rhythms (arrhythmias) which affect the upper chambers (atria) of the...ImageRead Article Now Book Mark Article Heart attack Heart failure Heart failureHeart failure is a condition in which the heart is no longer able to pump oxygen-rich blood to the rest of the body efficiently. This causes symptom...ImageRead Article Now Book Mark Article Multifocal atrial tachycardia Multifocal atrial tachycardiaMultifocal atrial tachycardia (MAT) is a rapid heart rate. It occurs when too many signals (electrical impulses) are sent from the upper heart (atri...ImageRead Article Now Book Mark Article Paroxysmal supraventricular tachycardia Paroxysmal supraventricular tachycardiaParoxysmal supraventricular tachycardia (PSVT) is episodes of a rapid heart rate that start in a part of the heart above the ventricles. "Paroxysmal...ImageRead Article Now Book Mark Article Sick sinus syndrome Sick sinus syndromeNormally, the heartbeat starts in an area in the top chambers of the heart (atria). This area is the heart's pacemaker. It is called the sinoatrial...ImageRead Article Now Book Mark Article Wolff-Parkinson-White syndromeWolff-Parkinson-White syndromeWolff-Parkinson-White (WPW) syndrome is a condition in which there is an extra electrical pathway in the heart that leads to periods of rapid heart r...ImageRead Article Now Book Mark Article Risks There are no risks. Considerations The accuracy of the ECG depends on the condition being tested. A heart problem may not always show up on the ECG. Some heart conditions never produce any specific ECG changes.Open ReferencesReferencesBrady WJ, Harrigan RA, Chan TC. Basic electrocardiographic techniques. In: Roberts JR, Custalow CB, Thomsen TW, eds. Roberts and Hedges' Clinical Procedures in Emergency Medicine and Acute Care. 7th ed. Philadelphia, PA: Elsevier; 2019:chap 14.Ganz L, Link MS. Electrocardiography. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 48.Mirvis DM, Goldberger AL. Electrocardiography. In: Libby P, Bonow RO, Mann DL, Tomaselli GF, Bhatt DL, Solomon SD, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Philadelphia, PA: Elsevier; 2022:chap 14.