Heartsounds in mitral regurgitation

What are the causes of soft S1 in mitral regurgitation

• It is due to the incomplete opposition of valve cusps
• There is partial closure of mitral valve orifice at the onset of ventricular systoli

Causes of loud S1 in MR

• Co-existing mitral stenosis
• MVP – MR
• MR due to papillary muscle dysfunction

What are the causes of left ventricular S3 in MR

• It is due to elevated left ventricular end diastolic volume (LVEDV)
• Due to left ventricular dysfunction – LV dysfunction