Texas Heart Institute Home
Continuing Medical Education
 
CME Home
Listen to podcast
 

Click on stethoscope to hear podcast.

 

Heart Sounds Podcast Series
Fixed Splitting of the Second Sound

 



When you hear the terms, wide, fixed splitting of the second heart sound, your brain should immediately convert this to "atrial septal defect." This finding on physical examination is very specific but not sensitive for atrial septal defect.

The principle is that with ventilation, right ventricular filling is accentuated, thus increasing the time for right ventricular ejection. During expiration, systemic venous filling is diminished while pulmonary venous filling of the left atrium is accentuated. With free access to the right atrium, the relatively under-filled chamber fills with shunted blood so that with inspiration or expiration, the right and left ventricles see the same amount of blood with each systole, the right ventricle seeing more. As a result, no matter whether in inspiration or expiration, the difference in time between the aortic and pulmonary valve closure sound remains very closely the same. Additionally, during physical exam of the patient, note also the visible evidence of a pulmonary valve impulse and listen for a short, midsystolic murmur. All these combine in a triumvirate of the physical diagnosis findings of atrial septal defect. 
 

Fixed Splitting of the Second Sound

 

Return to Heart Sounds Podcast Series


Updated December 2010
 
Find Us on Facebook!

Please contact our Webmaster with questions or comments.
Terms of Use and Privacy Policy
� Copyright Texas Heart Institute. All rights reserved.
Texas Heart Institute, Texas Heart, Texas Heart Institute Journal, THI, Heart Owner's, Leading With the Heart and Heart of Discovery are members of the
family of trademarks of the Texas Heart Institute.


U.S. NEWS America's Best Hospitals 2012-13