Second Degree Heart Block Type II ECG

ECG Strip

Second Degree Heart Block Type II Rhythm Strip Features

Rate: Characterized by Atrial rate usually faster than ventricular rate (usually slow)
Rhythm: Regular (atrial) and irregular (ventricular)
P Wave: Normal form, but more P waves than QRS complexes
PR Interval: Normal or prolonged
QRS: Normal or wide
A constant P-R interval with missing QRS complexes. Occurring in a specific pattern in a ratio with the P waves.
Second degree Heart Block Mobitz II is characterized by intermittently non-conducted P waves which are not preceded by PR prolongation and are not followed by PR shortening. Mobitz II is usually caused by conduction failure/delay of the His-Purkinje system. In three out of four cases, this conduction block is located distal to the Bundle of His, creating wide QRS complexes. In the other 25% of cases, the block is located within the Bundle of His, producing narrower QRS complexes.
External Source: http://http://texasheart.org/HIC/Topics/Cond/bbblock.cfm
Texas Heart Institute

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Authors and Sources

Authors and Reviewers

ECG heart rhythm modules: Thomas O'Brien.
ECG monitor simulation developer: Steve Collmann
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
ECG Reference Guide
PracticalClinicalSkills.com