First Degree Heart Block | Reference Guide
EKG FeaturesRate: The underlying rate
P Wave: Normal
PR Interval: Prolonged (>0.20 sec)
QRS: Normal (0.06-0.10 sec)
Will look like a typical sinus rhythm. The P-R interval will be constant throughout the tracing and measure greater than 0.20 seconds.
A first degree Heart block occurs when electrical impulses moving through the Atrioventricular (AV) node are delayed (but not blocked). First degree indicates slowed conduction without missed beats.
External Source: http://www.uptodate.com/contents/first-degree-atrioventricular-block
EKG Tracing Example
Authors and ReviewersAuthored by Thomas O'Brien
Medically reviewed by Dr. Jonathan Keroes, MD
Last Update: 11/8/2021