University:
West Coast University
Course:
NURS 110 | Introduction to Professional Nursing
Academic year:

2021
Views:

126

Pages:

2
Author:

Dawson Thornton

Rate Measurement The patient’s heart rate reveals a great deal of information. If the rate is slow (under 60 beats per minute), we call it bradycardia. If the heart rate is fast (over 100 beats per minute), then it is called tachycardia. ECG monitors display the heart rate. When an ECG strip is printed, most printers provide heart rate information at the top of the strip. Never the less, you might be in a situation where you must calculate the heart rate from the ECG recording. There are numerous methods and formulas, which can be used to calculate a heart rate from the ECG. Three methods for heart rate calculation are presented below. The Six Second Method This method can be used with either regular or irregular rhythms and provides a rough estimate (but not precise) of heart rate. Print a 6 second strip (see text box if you are not sure how to do this). Count the number of R waves in a 6 second strip and multiply by 10. For example, if there are seven (7) R waves in a 6 second strip, the heart rate is approximately 70 or (7x10=70). Let’s give it a try. Look at the rhythm below and count all the R waves. Large Box Method Count the number of large squares between two consecutive R waves. Divide this number into 300 for a ventricular rate. For example, if there are four large squares between regular QRS complexes, the heart rate is 75 (300/4=75). For an atrial rate, count the number of large boxes between two consecutive P waves and also divide into 300. Small Box Method This method also uses an “R to R” or “P to P” measurement, but is more precise because we use the smaller ECG boxes to help us calculate the heart rate. To calculate the ventricular rate, count the number of small boxes between two consecutive R waves and divide by 1500. To calculate the atrial rate, count the number of large boxes between two consecutive P waves and divide by 1500. For example, if there are two small squares between regular QRS complexes, the heart rate is 75 (1500/20 = 75). 9 Quick Method (used when rhythm is regular) Find an R wave that falls on a thick vertical line and count the number of boxes until the next Rwave. The duration between two consecutive R-waves is referred to as the RR interval. Then use the number range above, counting down for each large box. o 1 Box = 300 beats per minute (bpm) o 2 Boxes = 150 beats per minute (bpm) o 3 Boxes = 100 beats per minute (bpm) o 4 Boxes = 75 beats per minute (bpm) o 5 Boxes = 60 beats per minute (bpm) o 6 Boxes = 50 beats per minute (bpm)