An electrocardiogram (e-lek-tro-KAR-de-o-gram), also called an EKG or ECG, is a simple, painless test that records the heart's electrical activity. To understand this test, it helps to understand how the heart works.
With each heartbeat, an electrical signal spreads from the top of the heart to the bottom. As it travels, the signal causes the heart to contract and pump blood. The process repeats with each new heartbeat.
The heart's electrical signals set the rhythm of the heartbeat. For more detailed information and animations, go to the Health Topics How the Heart Works article.
An EKG shows:
Doctors use EKGs to detect and study many heart problems, such as heart attacks, arrhythmias (ah-RITH-me-ahs), and heart failure. The test's results also can suggest other disorders that affect heart function.
Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Electrocardiogram, visit www.clinicaltrials.gov.
September 4, 2012
Silent heart attacks are common and predict risk of death, MRI diagnosis shows
Magnetic resonance imaging (MRI) is more effective than electrocardiography (ECG) at identifying "silent" heart attacks, also known as unrecognized myocardial infarctions, according to a study performed by National Institutes of Health researchers and international colleagues.
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