Interval Measurement - Certified Ekg Technician Cet
- An EKG technician is measuring intervals on a patient with atrial fibrillation. The ventricular rate is irregularly irregular at 80-140 bpm, and QRS complexes vary between 0.08-0.10 seconds. There are no discernible P waves. Which measurement approach is most appropriate for this rhythm? Answer: Document absent PR intervals and report QRS range as 0.08-0.10 seconds In atrial fibrillation, P waves are absent so PR intervals cannot be measured. The appropriate approach is to document this absence and report the range of QRS measurements observed. Choice A attempts to measure non-existent PR intervals. Choice B omits documentation of the variation observed. Choice C unnecessarily complicates documentation when a range is more informative.
- An EKG technician notices that in leads V1-V3, the QRS duration measures 0.14 seconds, while in leads V4-V6, it measures 0.09 seconds. The PR interval is consistently 0.18 seconds across all leads. What is the most likely explanation for this finding, and how should intervals be reported? Answer: Possible bundle branch block pattern; report QRS as 0.14 seconds representing maximum duration This pattern suggests a bundle branch block where some leads show the complete QRS duration while others show incomplete electrical activity. The widest QRS (0.14 seconds) represents the true duration of ventricular depolarization and should be reported. Choice A may be considered but the pattern is more consistent with BBB. Choice B incorrectly uses narrower measurements. Choice D assumes artifact without considering pathological causes.