An electrocardiogram, also called an EKG or ECG, is a simple test that detects and records the electrical activity of the heart. It is used to detect and locate the source of heart problems.
Electrical signals in the heart trigger heartbeats. These signals start at the top of the heart in an area called the right atrium. (Read about "The Heart & Its Valves") The electrical signals travel from the top of the heart to the bottom. They cause the heart muscle to contract as they travel through the heart. As the heart contracts, it pumps blood out to the rest of the body. (Read about "The Heart & Cardiovascular System")
An EKG shows how fast the heart is beating. It shows the heart's rhythm, whether it is steady or irregular. It also records the strength and timing of the electrical signals as they pass through each part of the heart.
EKG recordings of this electrical activity can help reveal a number of heart problems, including but not limited to:
An EKG can also identify an area of the heart that is receiving less blood flow than is should, which can be an indication of a higher risk of a heart attack.
During an EKG, a technician first attaches soft patches called electrodes to the skin of the chest, arms and legs. These electrodes are about the size of a quarter. To help an electrode stick to the skin, the technician may have to shave a patch of hair where the electrode will be attached.
After the electrodes are placed on the skin, you lie still on a table for a few minutes while the electrodes detect the electrical signals of the heart. A machine then records these signals on graph paper or displays them on a screen.
The entire test takes about 10 minutes. After the test, the electrodes are removed from the skin and discarded.
Hammond-Henry Hospital Cardiopulmonary Services
600 North College Avenue
Geneseo, IL 61254