Originally Posted by belindalimm
What is the explanation for a loud S1 in ASD patients?
I thought ASD results in overflow through tricuspid valve as well as mitral valve, increasing the filling of the ventricles which elevates both of the valves. In this scenario, the S1 is decreased instead of being increased. Please correct me if it makes no sense. Thanks a lot!
Generally, in the setting of ASD, the flow through mitral valve decreases, because shunt flow from LA to RA through ASD result in decreasing flow through MV. As you know, increased flow through TV makes s1 louder due to volume loading of RV. I hope this will help you.