An electrocardiogram (EKG or ECG) is a test that checks for problems with the electrical activity of your heart. An EKG translates the heartâ€™s electrical activity into line tracings on paper. The spikes and dips in the line tracings are called waves.
The heart is a muscular pump made up of four chambers . The two upper chambers are called atria, and the two lower chambers are called ventricles. A natural electrical system causes the heart muscle to contract and pump blood through the heart to the lungs and the rest of the body.
If you have chest pain or other symptoms of heart disease, an electrocardiogram (EKG) or exercise stress test can be lifesaving. The same is true if you have a history of heart disease or are at very high risk for it. But in other cases, you should think twice.
With an EKG, electrodes attached to your chest record your heartâ€™s electrical activity. When an EKG is done as you walk or jog on a treadmill, itâ€™s called an exercise stress test. If you have symptoms of heart disease or are at high risk for it, both can help determine your chances of having a heart attack and help you and your doctor decide how to treat the problem.
But the tests are less accurate for lower-risk people and often have misleading results. Yet many people without symptoms of heart disease get the tests as part of their routine checkup. For example, in a 2010 Consumer Reports survey of nearly 1,200 people between the ages of 40 and 60 with no history of heart disease or heart-disease symptoms, 39 percent said they had undergone an EKG during the previous five years and 12 percent said they had an exercise stress test.
EKGs and exercise stress tests wonâ€™t harm you directly. But both can produce inaccurate results that trigger follow-up tests that can pose risks. Those include CT angiography, which can expose you to a radiation dose equal to 600 to 800 chest X-rays, and standard coronary angiography, an invasive procedure that exposes you to further radiation. The risk posed by any one source is uncertain, but the effect of radiation is cumulative, so itâ€™s best to avoid exposure when you can. Inappropriate testing can also lead to overtreatment with drugs or even angioplasty, a procedure that can ease the symptoms of heart disease but for many people is no better than lifestyle changes and medicationâ€”and triggers heart attacks in 1 to 2 percent of patients.
An EKG typically costs about $50 and an exercise stress test about $200 to $300, according to HealthcareBlueBook.com. But any money spent on unnecessary tests is money wasted. And subsequent interventions prompted by unneeded tests can add thousands to the tab
An EKG and exercise stress test are often necessary if you have chest pain, shortness of breath, an irregular heartbeat or palpitations, or other symptoms of heart disease. They can also make sense for people with diabetes or other risk factors who are just starting to exercise.