Here at the “Cardiac Care 101” corner of the A&K Global Health blog, we’ve recently been sharing about how the heart works and how to recognize and treat the most common heart diseases. These posts often reference the two most common cardiac diagnostic tools: ECGs and echoes. Today, we explain what these terms mean, what information these tests provide to doctors, and what the test experience involves for patients.
What is an ECG (electrocardiogram)?
An ECG detects heart abnormalities. It records the electrical activity of the heart, and can detect any abnormal rhythm (arrhythmia), infarct (heart attack), or hypertrophy (enlargement) of the heart. Although it may look scary with all the metal electrodes stuck to the arms, legs, and chest, the test is both painless and harmless. Wires from these electrodes are connected to the ECG machine, which detects the electrical activity that occurs at each heartbeat. This activity is then recorded onto a paper, allowing doctors to make a diagnosis.
- A Treadmill Test (TMT) is a specialized kind of ECG, conducted while the patient is exercising on the treadmill. Blood pressure is also recorded regularly during this test. A TMT is done to detect the severity of heart disease, when there are minimal or no symptoms, but abnormality is suspected based on the results of the standard ECG.
- Patients who complain of a pounding heartbeat that comes and goes may benefit from a Holter Monitor test. In this ECG variant, the patient wears a monitor for 24-48 hours that continuously records cardiac activity as they go about their usual routine.
What is an echo (echocardiogram)?
An echo takes a picture of the heart using high-frequency sound waves. This picture shows the shape and size of the valves and the heart chambers, the functioning of the heart, and the blood flow. Like the ECG, this is also a painless test where some gel is placed on the patient’s chest, and a probe (transducer) is moved over the chest to view the heart from different directions.
- A transesophageal echo, or TEE, is a special kind of echo in which a tube (endoscope) is used to guide the transducer down the esophagus. The TEE provides doctors with more detailed information about the heart than a standard echo. This test may be done in cases of aneurysm, other heart or blood vessel diseases, or to guide cardiac catheterization.
- A fetal echo is performed in order to examine an unborn baby’s heart during the second trimester of pregnancy. This test is used to detect congenital heart diseases.
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