How to Obtain Rate and Rhythm
From Ask Dr Wiki
What is the Rate
The normal range is from 60 to 100 bpm. There are several ways to calculate the rate that are listed below. To calculate the atrial rate you can locate two consecutive p waves and measure the number of large boxes between them. If there is 1 large box between the p waves then the rate is 300 bpm, 2 large boxes equals 150 bpm, 3 large boxes equals 75 bpm, 4 large boxes equals 60 bpm, 5 large boxes equals 50 bpm, and 6 large boxes equals 40 bpm. To calculate the ventricular rate measure the distance between the R to R intervals and apply the same rules.
What is the Rhythm
- The first step to determining the rhythm is to determine if the rhythm is regular or irregular. If the rhythm is fast (rate > 100 bpm) and irregular your differential should include Atrial Fibrillation, Multifocal Atrial Tachycardia , or Atrial Flutter with a variable rate (alternating between 2:1, 3:1, and 4:1). If the rhythm is fast and regular your differential should include Sinus Tachycardia, AVNRT, AVRT, and Atrial Flutter.
The next step in reading an EKG is How to Measure Intervals.