What is an EKG/ECG?
An electrocardiogram (EKG or ECG) is one of the simplest and fastest tests to assess the heart. It measures and interprets the electrical activity of your child's heart.
During an EKG, staff at the Heart Institute at UPMC Children’s Hospital of Pittsburgh will:
- Place small, plastic patches — called electrodes — on certain spots of your child's chest, arms, and legs.
- Connect the lead wires from the electrodes to the EKG machine.
- Print the results for your child's doctor to review.
What Does an EKG Tracing Show?
An EKG tracing consists of spikes and valleys, each of which measures a different part of your child’s heartbeat. Changes in an EKG from the normal tracing can mean one or more heart problems.
The parts of an EKG tracing and what they measure
- P wave: The first little upward notch of the EKG tracing is the P wave. The P wave shows that the atria (the two upper chambers of the heart) are electrically stimulated to pump blood to the ventricles.
- QRS complex: The next part of the tracing — the QRS complex — is a short downward section connected to a tall upward section. It indicates that the ventricles (the two lower chambers of the heart) are electrically stimulated to pump out blood.
- ST segment: The short, flat ST segment pinpoints the amount of time from the end of the contraction of the ventricles to the beginning of the T wave.
- T wave: The upward curve — called the T wave — measures the recovery period of the ventricles.
When the doctor studies your child's EKG, he or she looks at the size and length of each part of the EKG tracing. Variations in size and length of the parts of the tracing may be significant.
The tracing for each lead of a 12-lead EKG will look different, but will have the same basic parts as described above.
Each lead of the 12-lead "looks" at a unique part of the heart. Variations in a lead may mean there's a problem with that part of your child's heart.
Can Certain Conditions Cause Changes in an EKG?
Many health conditions can cause changes in the EKG pattern, such as:
- Heart enlargement — caused by factors such as heart defects present at birth (congenital), heart valve problems, high blood pressure, congestive heart failure, or conduction disturbances.
- Ischemia — a decrease in blood flow to the heart muscle, due to partial or total clogging of the arteries.
- Conduction disorders — a defect in the heart's electrical conduction system that can make the heart beat too fast, too slow, or at an uneven rate.
- Electrolyte disturbances — an imbalance in the level of electrolytes (or chemicals) in the blood, such as potassium, magnesium, or calcium.
- Pericarditis — an inflammation or infection of the sac that surrounds the heart.
- Valve disease — a problem with one or more of the heart valves that can obstruct the blood flow within the heart.
- Chest trauma — a blunt trauma to the chest.
Why Might My Child Need an EKG?
Besides assessing the health conditions above, there are many other reasons why your child might need an EKG.
Your child's doctor may perform an EKG to:
- Get a baseline tracing of the heart's function to compare with future EKGs and track changes.
- Make sure your child doesn't have an existing heart condition that might cause complications during a procedure or surgery.
- Check the function of an implanted pacemaker.
- Measure the effectiveness of certain heart medications.
- Confirm the heart's status after a procedure such as cardiac catheterization, electrophysiology studies, or heart surgery.
Depending on the results of the EKG, doctors may order other tests or procedures to gather further diagnostic information.
Make an Appointment for an EKG
To make an appointment or learn more about EKG testing, contact the Heart Institute at UPMC Children's Hospital at 412-692-5540.
Learn More About EKGs
View our electrocardiogram (EKG) patient procedure sheet.
