What is an electrocardiogram (ECG)?
An electrocardiogram is commonly called an ECG or EKG and it is a simple test used to check the rhythm and electrical activity of your heart. Sensors attached to the skin are used to detect the electrical signals your heart produces each time it beats. A machine records these signals, and the doctor sees if they are abnormal.
The electrocardiogram can be ordered by a cardiologist or any doctor who thinks you have a heart problem, including your GP. This test can be done by a hospital, clinic, or healthcare professional who is specially trained in surgery by your GP. Despite the similar name, the electrocardiogram is not the same as the echocardiogram, which is a scan of the heart.
Natural electrical impulses coordinate the contractions of different parts of the heart, causing blood to flow. An electrocardiogram records these impulses to show the strength and timing of the electrical impulses as the heartbeats, the rhythm of the heartbeat (constant or irregular), and the passage through different parts of the heart. Changes in the ECG indicate heart conditions.
Why is an electrocardiogram done?
Your doctor may recommend an electrocardiogram to assess the health of your heart. This is a common part of checkups, especially for those over 40.
An electrocardiogram by itself does not diagnose all types of heart conditions or predict future heart problems. Provides important information about your heart health-related to your age, physical exam, medical history, and other tests.
- Identify abnormal heart rhythms that cause blood to clot.
- Identifying heart problems includes a recent or ongoing heart attack, abnormal heart rhythms (arrhythmia), coronary artery occlusion, damaged areas of the heart muscle (from a previous heart attack), inflammation of the broken heart, and shock around the heart.
- Identify non-cardiac conditions such as electrolyte imbalance and lung and lung diseases.
- Heart attack, the progression of heart disease, or recovery from the effect of certain medications or pacemakers.
- Eliminate hidden heart disease in patients undergoing surgery.
When are ECGs needed?
In some cases, having this test is very important. If you have symptoms of high blood pressure or heart disease, chest pain, shortness of breath, irregular heartbeat, or large heartbeat, you may need an electrocardiogram. You may need screenings or tests for professional purposes or if you have a personal or family history of heart disease, diabetes, or other accidents and want to start exercising.
How the test is done
You will be asked to remove all clothing and jewelry from your waist (including women’s bras) to place electrodes on specific areas of the chest wall, arms, and legs. The electrodes are held in place by rubber bands, suction cups, or adhesive pads.
Sometimes it is necessary to shave the skin where the electrode recording patches are placed to easily detect the electrical signal and reduce discomfort when removing the patches. For a standard 12-bottle ECG, the electrodes are placed in 4 positions on the 4 extremities and 6 on the chest wall. Sometimes additional leads are added for a 15-lead electrocardiogram.
You will be prompted to remain normal when the machine is turned on, and typically a sample (usually 3-4 seconds) from each electrode site is recorded. The electrocardiogram is usually constantly monitoring and may ask you to hold your breath for a short time during the procedure (to stop chest wall movement that interferes with the signal). The machine captures the electrical activity of the wires and then produces a graph with an up and down row that looks a bit like a geographic map but indicates the activity of your heart.
Types of electrocardiogram
The types of ECG are:
- Standard (resting) ECG: The electrocardiogram measures the electrical activity of your heart while you lie down or rest in a semi-reclined position. This is the most common type of ECG.
- Stress test (exercise ECG or tape test): This usually involves taking an electrocardiogram on a treadmill while you exercise. Show how exercise affects your heart. Helps diagnose and diagnose coronary artery disease and other types of heart disease. Medications are sometimes given instead of mimicking the effect of exercise on the heart.
- Holter monitor (24-hour ECG or ambulatory ECG): This includes the use of an electronic electrocardiogram recorder 24 hours a day. It records the electrical activity of your heart for 24 hours. It can help diagnose arrhythmias (irregular or abnormal heartbeats).
- Cardiac event recorders record an electrocardiogram for an extended period, a year or more. Portable cardiac event recorders record the electrical activity of the heart when you have symptoms. Adjustable loop recorders are mounted under the skin on your chest. They constantly record the electrical activity of your heart.
Results of ECG
For most people, an electrocardiogram is just a series of lines. However, each line corresponds to an electrical signal sent from the heart. Doctors can read and understand these lines, which indicate the general condition of the heart.
The operating physician or healthcare professional places the electrodes on a person’s skin, usually around the chest, and at 10 different points on the extremities. Each beat sends an electrical impulse. These electrodes select this pulse and record the activity as a waveform on a graph.
All of these take place in the eyelid, so an EKG is very important. An ECG can capture all these little details and record them for the doctor to analyze.
Risk factors of ECG
Electrocardiograms (EKGs) are safe, non-invasive, painless, and accident-free tests. The electrodes (adhesive patches) that connect the sensors to your chest do not send electrical shocks. People who undergo stress tests have a higher risk of having a heart attack, but this is related to exercise, not the EKG.
You may develop a mild rash or irritation of the skin where the electrodes are placed. If paste or gel is used to place the electrodes, you may have an allergic reaction. This irritation usually disappears without the need for treatment, once the patches are removed.
Specialists who handle ECG
- Cardiac surgeons specialize in the surgical treatment of the heart and its vascular conditions. They are also known as cardiothoracic surgeons.
- Pediatric cardiologists and cardiologists are interns or pediatricians who specialize in diagnosing and treating diseases or situations of the heart and its blood vessels.
- Emergency medicine specialists specialize in the diagnosis and treatment of sudden illness or injury and difficulties of chronic illness.
- Interventional cardiologists are cardiologists who specialize in diagnosing and treating conditions and diseases of the heart and its blood vessels. They use catheter-based non-surgical procedures and imaging techniques.
- Primary care providers include interns, family practitioners (family medicine physicians), pediatricians, geriatricians, physician assistants (PA), and nurse practitioners (NP). Primary care providers provide comprehensive health services and treat a wide variety of ailments and conditions.
- Thoracic surgeons train in the surgical treatment of diseases of the chest, including the blood vessels, heart, lungs, and esophagus. They are also known as cardiothoracic surgeons.