Certified EkG technician (CET) Practice Exam

What is the characteristic of the EKG tracing for a patient who has atrial fibrillation?

1. Regular R-R intervals

2. R-R interval is irregularly irregular

3. Prolonged QRS intervals

4. Stable baseline with occasional extrasystoles

The correct answer is: R-R interval is irregularly irregular

Atrial fibrillation (AF) is distinguished by the chaotic electrical activity in the atria, which leads to an irregular heart rhythm. In the context of an EKG tracing, this results in R-R intervals that are not consistent—this is referred to as "irregularly irregular." The lack of a predictable pattern means that the time between beats varies, which is a hallmark of this arrhythmia. The EKG may also show the absence of distinct P waves, which are typically seen in normal sinus rhythms, and instead, the baseline may appear somewhat erratic due to the rapid and disorganized electrical activity. The irregular R-R intervals highlight the loss of coordinated contractions of the atria, which can cause the heart rate to fluctuate and further contribute to the characteristic appearance on the EKG. Other options do not accurately represent the defining features of atrial fibrillation. For instance, regular R-R intervals suggest a rhythm where intervals between heartbeats are consistent, which is not the case in AF. Prolonged QRS intervals could suggest other conduction issues but do not specifically indicate atrial fibrillation. Similarly, a stable baseline with occasional extrasystoles does not capture the primary characteristic of AF, which is the irregular rhythm rather than occasional interruptions