CRAT Practice Exam 2025 – Complete Guide for Test Preparation

To determine the atrial rate from a rhythm strip displaying a regular rhythm with 5 complete cycles, it's essential to understand the method of calculating the heart rate. The atrial rate refers to the number of atrial contractions (or P waves) occurring in one minute.

In this scenario, the rhythm strip shows 5 complete cycles, which represent 5 atrial contractions. The next step is to ascertain how long the rhythm strip is and to convert the number of cycles into a rate.

Assuming that the rhythm strip is recorded for a standard duration of 6 seconds (which is typical for evaluating heart rhythms), we can use the formula to calculate the rate:

1. Count the number of cycles (or P waves) over 6 seconds (which, in this case, is 5).

2. Multiply the number of cycles by 10 to extrapolate the rate over one minute (since there are 60 seconds in a minute and our strip is 6 seconds long).

Therefore:

5 cycles × 10 = 50 beats per minute.

This calculation supports the determination of the atrial rate as 50 BPM for this particular rhythm strip. In practice, a rate of 50 BPM might indicate bradycardia depending on