Electrocardiography (EKG) measures the heart’s electrical activity to help evaluate its function and identify any problems that might exist. The EKG can help determine the rate and regularity of heartbeats, the size and position of the heart’s chambers, and whether there is any damage present.
How Is an EKG Done?
There is nothing painful about getting an EKG. The patient is asked to lie down, and a series of small metal tabs (called electrodes) are fixed to the skin with sticky papers. These electrodes are placed in a standard pattern on the shoulders, the chest, the wrists, and the ankles. After the electrodes are in place, the person is asked to hold still and, perhaps, to hold his or her breath briefly while the heartbeats are recorded for a short period.
The information is interpreted by a machine and drawn as a graph. The graph consists of multiple waves, which reflect the activity of the heart. The height, length, and frequency of the waves are read in the following way:
- The number of waves per minute on the graph is the heart rate.
- The distances between these waves is the heart rhythm.
- The shapes of the waves show how well the heart’s electrical impulses are working, the size of the heart, and how well the individual components of the heart are working together.
- The consistency of the waves provides relatively specific information about any heart damage present.
A person’s heartbeat should be consistent and even. EKGs look for abnormally slow and fast heart rates, abnormal rhythm patterns, conduction blocks (short-circuits of the heart’s electrical impulses that cause rhythm inconsistencies between the upper and lower chambers) — and four types of heart damage:
- ventricular hypertrophy — an abnormal thickening of the heart muscle
- ischemia — caused by an abnormally decreased blood supply
- cardiomyopathies — abnormalities in the heart muscle itself
- electrolyte and drug disturbances — these can alter the heart’s electrochemical environment
How Long Will it Take to Get Results?
Results of the EKG are available immediately. In fact, the EKG machine’s computer even provides an instant interpretation of the findings as it makes the report.
Reference ranges for heart rate and the relative lengths and sizes of the various components of the heartbeat figures vary, and diagnostic differences may be subtle, requiring an expert eye to detect them.
The experts at the CHOC Heart Institute perform thousands of EKGs a year, as well as other noninvasive cardiodiagnostic tests and procedures. In addition, the CHOC Heart Institute is the only pediatric facility in So Cal with all brand new, state of the art cardiac facilities including:
- Two Biplane cardiac catheterization labs (Hybrid Lab and EP Lab)
- Philips iE33 3-D Echocardiography
- 1.5 and 3.0 TESLA MR and CT Angiography with 3-D Image Reconstruction
- Two dedicated CV-ORs with the latest heart-lung bypass technology
- Pediatric ergometer and treadmill stress-testing
- Pediatric cardiopulmonary exercise testing (CPX)
- Certified Pediatric Cardiac clinical staff
- Pediatric Cardiac Nurse Practitioners, Social Workers and Child Life specialists to make your child and family as comfortable as possible.
Get more expert health advice delivered to your inbox monthly by subscribing to the KidsHealth newsletter here.
Learn more about CHOC’s Heart Institute
CHOC Hospital was named one of the nation’s best children’s hospitals by U.S. News & World Report in its 2024-25 Best Children’s Hospitals rankings and ranked in the cardiology and heart surgery specialties.
