Reading An EKG Quickly


This guide was created to provide a rapid approach to reading an EKG. Often times in medicine we will have to interpret the results of an EKG quickly, and having a clear algorithm of what to do can be very useful.

Those looking for a more detailed explanation more comprehensive guide to reading an EKG should go here.


Below is a practical method to reading EKGs that covers all the most important elements.

  1. Check the patient name: this seems silly, however the first step of reading an EKG should always be to make sure you are reading the correct patient’s study.
  2. Check the heart rate: the number of QRS complexes on the 10 second strip multiplied by 6 will give you the heart rate.
  3. Sinus rhythm: p waves need to be present (look to see them in leads I, II, and III), the tracing should be positive in lead II, and negative in AVR
  4. Axis deviation: the table below helps summarize how to determine axis deviation. screen-shot-2015-12-07-at-10-33-38-am
  5. PR interval: check to make sure this distance is larger then 3 small boxes (0.12 s) below the size of one big box (0.2 s)
  6. QRS intervalthis should be less then 0.10 sec (~3 boxes)
  7. QT interval: First calculate the time between the two subsequent R-R points (time between 2 ventricular contractions) and then make sure the QT interval is less than half this amount of time. Greater than half the RR interval is referred to as a prolonged QT.
  8. ST segment: look throughout the leads for any ST segment depression or elevation.


Page Updated: 09.28.2016