electrocardiogram

When the cardiac action potentials spread through the heart, electrical current also spreads from the heart into the adjacent tissues surrounding the heart. A small portion of the current spreads all the way to the surface of the body. If electrodes are placed on the skin on opposite sides of the heart, electrical potentials generated by the current can be recorded; the recording is known as an electrocardiogram. Common abbreviations: ECG, EKG. A patient's ECG can be useful for diagnosing and monitoring many types of heart disease.

Definition source: Guyton Medical Physiology Textbook.