First Heart Sound plus Aortic Ejection ClickA single first heart sound (S1) followed by an aortic ejection click (AEC) can also mimic a split first heart sound. An AEC follows S1 by 50 milliseconds. An aortic ejection click is caused by thickened aortic valve leaflets. This is commonly seen in a bicuspid aortic valve, a congenital abnormality where someone is born with two aortic valve leaflets instead of the normal three. Listen carefully to the second sound of the pair. If it is an AEC it will have a shorter duration and a higher pitch than the first sound of the pair (S1). The AEC is best heard at the Aortic valve area where splitting of S1 is not heard.
Half Speed Patient Sounds
The patient's position should be sitting.
Auscultation TipsSystole:high-pitched sound, early in systole, short duration
Observe Cardiac Animation
An aortic ejection click is caused by thickened aortic valve leaflets. This is commonly seen in a bicuspid aortic valve, a congenital abnormality where someone is born with two aortic valve leaflets instead of the normal three.
Return to Reference Guide Index Page
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
First Heart Sound plus Aortic Ejection Click | #43