Second Degree Heart Block Type I ECG Interpretation with Sample Strip
ECG Strip
Second Degree Heart Block Type I Rhythm Strip Features
Rate: The underlying rateRhythm: Irregular but with progressively longer PR interval lengthening
P Wave: Normal
PR Interval: Progressively longer until a QRS complex is missed, then cycle repeats
QRS: Normal (0.06-0.10 sec)
A prolonging P-R interval from one cardiac complex to the next, until it reaches a point where the QRS complex is non-conducted (blocked or more simply missing). Then the pattern starts over again.
Second degree Heart Block Type I Wenckebach is a condition where the atrioventricular node conducts each successive impulse earlier and earlier. The PQ interval prolongs from beat to beat up until a drop-out of one QRS complex. The following impulse will then be conducted normally and the cycle to begin again. Thus, the presence of second-degree AV block is diagnosed when one or more (but not all) of the atrial impulses fail to conduct to the ventricles.
External Source: http://www.uptodate.com/contents/second-degree-atrioventricular-block-mobitz-type-i-wenckebach-block
UpToDate
Authors and Sources
Authors and Reviewers
- ECG heart rhythm modules: Thomas O'Brien.
- ECG monitor simulation developer: Steve Collmann
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12 Lead Course: Dr. Michael Mazzini, MD.
- Spanish language ECG: Breena R. Taira, MD, MPH
- Medical review: Dr. Jonathan Keroes, MD
- Medical review: Dr. Pedro Azevedo, MD, Cardiology
- Last Update: 11/8/2021
Sources
-
Electrocardiography for Healthcare Professionals, 6th Edition
Kathryn Booth and Thomas O'Brien
ISBN10: 1265013470, ISBN13: 9781265013479
McGraw Hill, 2023 -
Rapid Interpretation of EKG's, Sixth Edition
Dale Dublin
Cover Publishing Company -
EKG Reference Guide
EKG.Academy -
12 Lead EKG for Nurses: Simple Steps to Interpret Rhythms, Arrhythmias, Blocks, Hypertrophy, Infarcts, & Cardiac Drugs
Aaron Reed
Create Space Independent Publishing -
Heart Sounds and Murmurs: A Practical Guide with Audio CD-ROM 3rd Edition
Elsevier-Health Sciences Division
Barbara A. Erickson, PhD, RN, CCRN -
The Virtual Cardiac Patient: A Multimedia Guide to Heart Sounds, Murmurs, EKG
Jonathan Keroes, David Lieberman
Publisher: Lippincott Williams & Wilkin)
ISBN-10: 0781784425; ISBN-13: 978-0781784429 - Project Semilla, UCLA Emergency Medicine, EKG Training Breena R. Taira, MD, MPH
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ECG Reference Guide
PracticalClinicalSkills.com