Just like your computer or your coffee pot, your cardiovascular system uses electric power. One big difference is that the heart furnishes its own electricity! With each beat, electrical impulses run from the top to the bottom of your heart. This makes your heart contract and pump blood. Your doctor can use a test called an electrocardiogram—often referred to as an EKG or ECG—to check the function of this wiring system. When you go for the test, a nurse or technician will attach about 12 soft, sticky patches to your body. Each patch holds an electrode that monitors your heart’s electrical activity. EKGs help your doctor detect or diagnose a wide variety of heart problems, from irregular heartbeats to heart attack. He or she may order an EKG for the following reasons. As Part of a Routine Health Exam Because they cost little and don’t require incisions or needles, doctors often use EKGs to screen for heart disease in people who have no symptoms. You might receive one during your regular physical exam, especially if you have a close family member with heart disease. Keep in mind that EKG results tend to be more accurate in people with a high risk of heart disease. In healthy people with no symptoms, the test sometimes gives false positives. This can lead to more testing and potentially invasive and unnecessary treatments. Before you have a medical test, make sure you ask your doctor why you need it. Ask him or her to explain all the potential benefits and risks. Together, you can make the best choice for you and your health. If You Have Symptoms of a Heart Problem Heart disease causes many symptoms—some of which are similar to signs of other diseases. If you have any of the following problems, your doctor may run an EKG to see if heart trouble is the culprit: Chest pain Fatigue Pounding, racing or fluttering heartbeats Trouble breathing Weakness Different heart problems change the heart’s electrical pattern in different ways. EKG results can help your doctor identify and diagnose: Arrhythmia, or irregular heartbeat Congenital heart defects Coronary artery disease, or a lack of blood flow to the heart Heart failure, when your heart can’t pump enough blood through your body Pericarditis, an infection or inflammation of the fluid around the heart Problems with the valves in your heart Thick or enlarged heart muscles, a condition called cardiomyopathy To See If You’ve Had a Heart Attack When you arrive at the emergency room with symptoms of a heart attack, an EKG is often the first test you’ll undergo. Your doctor can tell from the electrical impulses of your heart whether you’ve had a heart attack or another heart problem. The results are even more helpful if your doctor can compare them to an EKG you had earlier. To Check Up on Your Treatment If you’ve already received a diagnosis of heart disease, your doctor may perform an EKG when you come in for a visit. The results tell him or her how well your medications, pacemaker, or other treatments are working. You might also get an EKG before major surgery, to make sure it is safe for you to have anesthesia. When Starting a New Exercise Routine Most healthy people can safely do moderate exercise without heart tests. But if you have diabetes or another chronic condition and have decided to start a new routine, your doctor may advise an EKG to rule out any hidden heart problems that might worsen during physical activity. Key Takeaways Before an EKG, ask your doctor to explain why you need it, as well as the test’s potential benefits and risks, so you can make informed health decisions. If you experience heart disease symptoms, contact your doctor. He or she may run an EKG to diagnose the problem. If you have a chronic condition and want to start a new exercise routine, ask your doctor whether an EKG is necessary to rule out hidden heart problems.