EKC or ECG stands for electrocardiogram. It is a recorded visual representation of the electrical impulses in the heart that make it beat. Physicians use EKGs to diagnose potential illness within the heart. This depends on observing deviations from the normal EKG reading, which is used as a baseline for diagnosis.
Normal Sinus Rhythm
A normal EKG reading is referred to as normal sinus rhythm. It is made up of waves displayed as a tracing on a metric grid. Each heartbeat consists of a P wave, a QRS complex, an ST segment, a T wave and U waves.
In normal sinus rhythm, each P wave appears as a bump in the tracing between 60 and 100 beats per minute. Normal P waves should appear less than 2.5 mm high and 0.11 seconds wide in lead II in a twelve-lead EKG.
After the P wave, there is a short straight line leading to the QRS complex.
A normal QRS complex follows the P wave and appears as a spike on the tracing. It should be less than 0.12 seconds long.
The ST segment is a straight line between the QRS complex and the T wave and should not display any elevation or depression.
Following the QRS complex, a T wave appears as a slightly smaller bump than the P wave. It should not be tall, flattened or inverted.