Editing First-degree atrioventricular block (section)

== Prognosis ==

Isolated first-degree heart block has no direct clinical consequences. There are no symptoms or signs associated with it. It was originally thought of as having a benign prognosis. In the [[Framingham Heart Study]], however, the presence of a prolonged PR interval or first degree AV block doubled the risk of developing [[atrial fibrillation]], tripled the risk of requiring an [[artificial pacemaker]], and was associated with a small increase in mortality. This risk was proportional to the degree of PR prolongation.<ref>{{cite journal |vauthors=Cheng S, Keyes MJ, Larson MG, McCabe EL, Newton-Cheh C, Levy D, Benjamin EJ, Vasan RS, Wang TJ | title=Long-term outcomes in individuals with prolonged PR interval or first-degree atrioventricular block | journal=JAMA | year=2009 | volume=301 | issue=24 | pages=2571–2577 | doi=10.1001/jama.2009.888| pmid=19549974 | pmc=2765917 }}</ref>

A subset of individuals with the triad of first-degree heart block, [[right bundle branch block]], and either [[left anterior fascicular block]] or [[left posterior fascicular block]] (known as [[trifascicular block]]) may be at an increased risk of progression to [[complete heart block]].<ref>{{cite web |url= https://www.lecturio.com/concepts/atrioventricular-block/ | title= Atrioventricular Block | website= The Lecturio Medical Concept Library |access-date= 3 July 2021}}</ref>