Free Trial #5


The nurse is caring for a client admitted to the emergency department with chest pain the following 12-lead electrocardiogram is depicted below. What is the approximate heart rate?


  1. 84-88 beats per minute
    • Rationale:
  2. 100-110 beats per minute
    • Rationale:
  3. 55-60 beats per minute
    • Rationale:
  4. Heart rate cannot be calculated on 12-lead
    • Rationale:



Heart rate can be calculated by simply counting the R-R segments in a 6-second strip for regular or irregular rhythms and multiply by 10 ( R intervals x 10). It is quickest but least accurate.

If 6-second strip is unavailable and rhythm is regular count the boxes (each large box has 5 small boxes (makes it easier to count large by 5 first, then add the smaller boxes) between an R-R interval and divide 1500 by the number of boxes. Ex: The above strip will have approximately 17.5 (nearly 18 small boxes) between two R – R intervals. 1500/17.5 = 85.7 beats/min

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