1. Fast & Easy ECGs, 2nd E – A Self-Paced Learning Program4
Heart Rate
Fast & Easy ECGs, 2nd E – A Self-Paced Learning Program

2. Dysrhythmias Irregularities in heart rate or rhythm
Some are of little significance whereas others are life threatening
Instructional point:
Emphasize that whenever dysrhythmias are present the patient must be assessed. Part of this assessment should include checking the patient’s pulse. I

3. Determining the Heart Rate
Is one of first steps in analyzing an ECG tracing
Answer: slow
Instructional points:
A quick assessment of the heart rate can be done by looking at the space between QRS complexes. More space indicates a slow heart rate while less space indicates a faster heart rate.
Heart rate x stroke volume = cardiac output. A very slow or fast heart rate can cause cardiac output to decrease by lowering the rate or decreasing the stroke volume. Compromised cardiac output requires immediate treatment. I

4. Determining the Heart Rate
Begin by quickly checking ECG monitor or tracing to see if rate is slow, normal or fast

5. Calculating Heart Rate
Several methods can be used including:
6-Second Interval x 10 Method
300, 150, 100, 75, 60, 50 Method
1500 Method
Rate Calculator
Instructional point:
The P waves can be counted to determine the atrial rate and the QRS complexes counted to determine the ventricular rate. I

6. 6-Second Interval x 10 Method
Quick, easy and does not require tools or devices
Multiply by 10 the number of QRS complexes found in a 6 second portion of the ECG tracing
Instructional points:
Typically there are markings on the top and/or bottom indicating each 3-second block of time. Two of these successive (adjacent to each other) blocks of time equal six seconds. When you multiply that amount of time by ten, it represents 60 seconds or one minute.
With very irregular rhythms try using a 12 second area of the tracing, count the number of QRS complexes (and/or P waves) multiply them by 5 (instead of 10). I

7. Practice Makes Perfect
For this tracing, determine the heart rate using the 6-second interval x 10 method
Answer: 200 beats per minute. I

8. Practice Makes Perfect
For this tracing, determine the heart rate using the 6-second interval x 10 method
Answer: 140 beats per minute. I

9. Practice Makes Perfect
For this tracing, determine the heart rate using the 6-second interval x 10 method
Answer: 50 beats per minute. I

10. 300, 150, 100, 75, 60, 50 Method
Quick, fairly accurate, requires no special tools, or calculations
Cannot be used with irregular rhythms
Find an R wave located on a bold line. Then find the next consecutive R wave. Bold line it falls on (or is closest to) represents the heart rate

11. 300, 150, 100, 75, 60, 50 Method
In this example: the 2nd R waves falls between the 4th and 5th bold line. As such the heart rate is between 60 and 75 BPM
If the 2nd R wave does not fall on a bold line the heart rate can be approximated

12. 300, 150, 100, 75, 60, 50 Method
If the second R wave falls in between two bold lines the heart rate can be more precisely determined using the identified values for each thin line
Instructional point:
It may be hard for the student to remember these values; for this reason the student may want to carry a card with those numbers listed. I

13. Practice Makes Perfect
For this tracing, determine the heart rate using the 300, 150, 100, 75, 60, 50 method
Answer: 125 beats per minute I

14. Practice Makes Perfect
For this tracing, determine the heart rate using the 300, 150, 100, 75, 60, 50 method
Answer: 75 beats per minute I

15. Practice Makes Perfect
For this tracing, determine the heart rate using the 300, 150, 100, 75, 60, 50 method
Answer: 41 beats per minute I

16. 1500 Method
Most accurate and requires no special tools but math calculation must be done to determine heart rate
Cannot be used with irregular rhythms
Count the number of small squares between two consecutive R waves and divide 1500 by that number
Instructional point:
An example is if you have 20 small squares (which is equal to four large boxes) the heart rate is 75 beats per minute (we arrive at this by dividing 1500 by 20). This can be used to calculate the atrial rate as well by measuring the number of small squares between the peaks of two consecutive P waves. I

17. Practice Makes Perfect
For this tracing, determine the heart rate using the 1500 method
Answer: 41 beats per minute I

18. Practice Makes Perfect
For this tracing, determine the heart rate using the 1500 method
Answer: 94 beats per minute I

19. Practice Makes Perfect
For this tracing, determine the heart rate using the 1500 method
Answer: 59 beats per minute I

20. Rate Calculators Easy to use but not always available
Ineffective on irregular rhythms where a consistent baseline is not present
Position the “start mark” on an R wave
Then find the next consecutive R wave – where it lines up is the approximate heart rate

21. Heart Rates Average adult has a heart rate of 60-100 BPM
Heart rate < 60 BPM called bradycardia
Heart rate > 100 BPM called tachycardia
Instructional point:
Both bradycardia and tachycardia can occur for many reasons. I

22. Summary
One of the 9 steps to analyzing an ECG rhythm is to determining the heart rate
To determine the heart rate first check to see if the rate is slow, normal or fast
Several techniques can be used to determine the heart rate
Instructional point:
If a dysrhythmia is present, compare your finding with your assessment of the patient. I

23. Summary
The 6-second interval x 10 method multiplies by 10 the number of QRS complexes found in a 6-second portion of the ECG tracing
The 300, 150, 100, 75, 60, 50 method involves locating an R wave on a bold line on the ECG paper, then finding the next consecutive R wave and using the 300, 150, 100, 75, 60, 50 values for subsequent bold lines to determine the rate
To use the 1500 method count the number of small squares between two consecutive R waves and divide 1500 by that number
Instructional point:
Remind the students that the QRS complexes are counted to determine the ventricular rate and the P waves are counted to determine the atrial rate. I

24. Summary
A heart rate less than 60 beats per minute is called bradycardia
A heart rate greater than 100 beats per minute is called tachycardia
Instructional point:
Remind the students that both extremely slow and fast heart rates can result in decreased cardiac output. I