Electrocardiogram (ECG)

Definition

An electrocardiogram (ECG) is a medical test that records the electrical activity of the heart over a period of time. It is used to diagnose and monitor heart conditions by displaying this activity as waveforms on a graph.

5 Must Know Facts For Your Next Test

1. The ECG can detect various cardiac abnormalities such as arrhythmias, myocardial infarctions, and electrolyte imbalances.
2. Electrodes are placed on the skin to measure the heart's electrical signals during an ECG.
3. The standard ECG has 12 leads, which provide different views of the heart's electrical activity.
4. P waves, QRS complexes, and T waves are key components analyzed in an ECG readout.
5. The first practical ECG was developed by Willem Einthoven, who won a Nobel Prize for his work.

Review Questions

• What does an electrocardiogram (ECG) measure?
• How many leads are used in a standard ECG?
• Name three types of information or conditions that an ECG can help diagnose.

Related terms

Arrhythmia: An irregular heartbeat that can be detected using an ECG.

Myocardial Infarction: A condition commonly known as a heart attack, detectable through changes in the ECG.

P Wave: The part of an ECG tracing that represents atrial depolarization.