Rhythm - EKG Basics
For ventricular rhythms, examine the R to R intervals on the ECG strip. Calipers or paper marks can be used to fix the distance for one R-R interval and then this distance can be compared to other R-R pairs. Within this web site, you will also be able to use virtual calipers.
Are they regular, meaning that each heart beat's R-R interval is equal? Small variations of up to 10% are considered equal. Is the rhythm regularly irregular? For example is there a pattern, such as increasing R-R durations? Or perhaps groups of similar intervals as illustrated on the right? Or are R-R intervals completely irregular?
For atrial rhythm, observe the P-P intervals. Are they regular (minor variations can be caused by the breath cycle)? If P-P intervals are irregular, is there a pattern?
Authors and Sources
Authors and Reviewers
- ECG heart rhythm modules: Thomas O'Brien.
- ECG monitor simulation developer: Steve Collmann
12 Lead Course: Dr. Michael Mazzini, MD.
- Spanish language ECG: Breena R. Taira, MD, MPH
- Medical review: Dr. Jonathan Keroes, MD
- Medical review: Dr. Pedro Azevedo, MD, Cardiology
- Last Update: 11/8/2021
Electrocardiography for Healthcare Professionals, 5th Edition
Kathryn Booth and Thomas O'Brien
ISBN10: 1260064778, ISBN13: 9781260064773
McGraw Hill, 2019
Rapid Interpretation of EKG's, Sixth Edition
Cover Publishing Company
12 Lead EKG for Nurses: Simple Steps to Interpret Rhythms, Arrhythmias, Blocks, Hypertrophy, Infarcts, & Cardiac Drugs
Create Space Independent Publishing
Heart Sounds and Murmurs: A Practical Guide with Audio CD-ROM 3rd Edition
Elsevier-Health Sciences Division
Barbara A. Erickson, PhD, RN, CCRN
The Virtual Cardiac Patient: A Multimedia Guide to Heart Sounds, Murmurs, EKG
Jonathan Keroes, David Lieberman
Publisher: Lippincott Williams & Wilkin)
ISBN-10: 0781784425; ISBN-13: 978-0781784429
- Project Semilla, UCLA Emergency Medicine, EKG Training Breena R. Taira, MD, MPH