Atrial Septal DefectThis is an auscultation example of an atrial septal defect as heard at the pulmonic position. Atrial Septal Defect is a congenital condition associated with abnormal blood flow between the left atrium and the right atrium. Before birth there is a large connection between right and left atria. During development of the fetus the connection gradually disappears. However, in some cases the opening persists and is known as an atrial septal defect. Both the first and second heart sounds are split. The second heart sound splitting is fixed at 80 milliseconds. There is a brief diamond shaped murmur in early systole and another brief diamond shaped murmur in early diastole In the anatomy video you see an enlarged right atrium and right ventricle. You see turbulent blood flow across the tricuspid valve between the right atrium and the right ventricle (the diastolic murmur). This is caused by blood flow from the left atrium into the right atrium through the atrial septal defect. There is further turbulent flow into the pulmonary artery causing the systolic murmur.
Half Speed Patient Sounds
The patient's position should be supine.
Systole:Diamond shaped, brief, early murmur
Diastole:Diamond shaped, brief, early murmur
Observe Cardiac Animation
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
Electrocardiography for Healthcare Professionals, 5th Edition
Kathryn Booth and Thomas O'Brien
ISBN10: 1260064778, ISBN13: 9781260064773
McGraw Hill, 2019
Rapid Interpretation of EKG's, Sixth Edition
Cover Publishing Company
12 Lead EKG for Nurses: Simple Steps to Interpret Rhythms, Arrhythmias, Blocks, Hypertrophy, Infarcts, & Cardiac Drugs
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