QT Interval Lesson and Quiz

The QT interval represents the time of ventricular activity including both depolarization and repolarization.

It is measured from the beginning of the QRS complex to the end of the T wave. Normally, the QT interval is 0.36 to 0.44 seconds (9-11 boxes). The QT interval will vary with patient gender, age and heart rate. Another guideline is that normal QT Intervals is less than half of the R-R Interval for heart rates below 100 bpm.

QT Interval illustration

second image

EKG Basics Quiz

Table of Contents

back button next button

Conceptos Básicos ECG