Upon review of an EKG, you notice periodic, repetitively absent QRS complexes and "grouped beating." Which of the following is the explanation?
- Third-degree heart block
- Mobitz Type II heart block
- Mobitz Type I heart block
- First-degree heart block
- Sinus tachycardia
Answer: C
Mobitz Type I heart block
I don't like the wording of this question, but typically "group beating" suggests Wenckebach. The fact that there are absent QRS complexes means there is a second or third-degree AVB. In Mobitz II, the PR intervals are the same - so no "grouped" beating, in Third degree, there is no rhyme or reason to the rhythm. In Wenckebach, the rhythm "repeats", causing a "regularly irregular" rhythm.
Know Your Content Blueprint
Mobitz Type I heart block is covered in the NCCPA™ Content Blueprint Cardiology System (16%)
View Topic: Atrioventricular block