Question

When analyzing an electrocardiographic (ECG) rhythm strip of a patient with a regular heart rhythm, the nurse counts 30 small blocks from one R wave to the next. The nurse calculates the patient's heart rate as:

A) 50 beats per minute
B) 75 beats per minute
C) 100 beats per minute
D) 120 beats per minute

Answer 1

The patient's heart rate calculated from an ECG strip with 30 small blocks between R waves is 50 beats per minute. This is determined by dividing 1500 small blocks (representing one minute) by the number of small blocks in the R-R interval.

Step-by-step explanation:

When analyzing an electrocardiographic (ECG) rhythm strip, if a nurse counts 30 small blocks from one R wave to the next, the patient's heart rate can be calculated using the standard ECG grid where each small block is 0.04 seconds. Since there are 1500 small blocks in one minute (60 seconds), the heart rate is determined by dividing 1500 by the number of small blocks between R waves. In this case:

1500 small blocks/min ÷ 30 small blocks/R-R interval = 50 beats per minute.

Therefore, the correct calculation of this patient's heart rate would be 50 beats per minute, which falls below the normal resting heart rate range of 60-100 beats per minute indicating that the patient might have bradycardia if this rate is observed at rest.