S3

• May be normal in people under 40 years of age and some trained athletes but should disappear before middle age.

• Caused by the oscillation of blood back and forth between the walls of the ventricles initiated by in-rushing blood from the atria.

Due to:

1.Rapid ventricular filling

•   Ventricular decompensation (acutely)
•   Ventricular Septal Defect

2.Severe aortic or mitral regurgitation

3.Poor Left Ventricular Function –Post MI –Dilated Cardiomyopathy  (acutely)

  Ventricular Septal Defect