What are the two sets of triplets found after an R wave?

What are the two sets of triplets found after an R wave?

• A. 300, 250, 150
• B. 300, 150, 100
• C. 75, 100, 50
• D. 300, 150, 75

Answer: (B)

The correct answer identifies the relationship between heart rate and the intervals present on an electrocardiogram (EKG). The two sets of triplets mentioned refer to the commonly used method of estimating heart rate by counting the number of large boxes between R waves.

In this context, the triplet of values typically represents the number of large boxes that correlate with specific heart rates: if one large box equals 300 beats per minute (bpm), two large boxes represent 150 bpm, and three large boxes correspond to 100 bpm. Each of these values reflects a specific heart rate based on the formula used in the 1500 method for calculating heart rate, where the full EKG grid is utilized.

The answer outlines a logical progression in heart rates using intervals that a clinician can intuitively grasp when assessing an EKG rhythm quickly. This familiarity serves as a foundational tool in emergency and clinical practices to identify rates efficiently.