First degree AV block nomenclature

Q: First-degree AV block is a misnomer?

A) True

B) False

Answer: A

First-degree Atrioventricular block is defined as a prolonged PR interval of >200 ms at resting heart rates. In a true sense, it is just delayed or slowed AV conduction. It is not a true block. Instead of first-degree AV block, it should be called "prolonged AV conduction." It mostly occurs in the AV node but may also occur in the His-Purkinje system.

Previously, it was thought to be completely a benign condition, but new research argues to investigate it thoroughly as it may signify a serious underlying cardiac disease.

#cardiology

References/further reading:

1. Holmqvist F, Daubert JP. First-degree AV block-an entirely benign finding or a potentially curable cause of cardiac disease? Ann Noninvasive Electrocardiol. 2013 May;18(3):215-24. doi: 10.1111/anec.12062. PMID: 23714079; PMCID: PMC6932444.

2. Liu M, Du Z, Sun Y. Prognostic significance of first-degree atrioventricular block in a large Asian population: a prospective cohort study. BMJ Open. 2022 Apr 4;12(4):e062005. doi: 10.1136/bmjopen-2022-062005. PMID: 35379649; PMCID: PMC8981319.