How is S1 in mitral stenosis (MS)?
Booming (in 90% of the patients). A loud S1 should always alert the clinician to the possibility of MS and
thus prompt a search for its associated diastolic rumble. Conversely, a soft S1 argues against the presence of uncomplicated MS (i.e., one where the valve is still relatively pliable). The loud S1 is usually the result of:
Thickening of the mitral leaflets: In the late stages of MS, however, leaflets can become stiff and poorly mobile, which, in turn, softens S1 and eventually eliminates it.
High atrioventricular pressure gradient: This is produced by the stenotic valve and keeps the A-V leaflets maximally separated at the onset of ventricular contraction.
Booming (in 90% of the patients). A loud S1 should always alert the clinician to the possibility of MS and
thus prompt a search for its associated diastolic rumble. Conversely, a soft S1 argues against the presence of uncomplicated MS (i.e., one where the valve is still relatively pliable). The loud S1 is usually the result of:
Thickening of the mitral leaflets: In the late stages of MS, however, leaflets can become stiff and poorly mobile, which, in turn, softens S1 and eventually eliminates it.
High atrioventricular pressure gradient: This is produced by the stenotic valve and keeps the A-V leaflets maximally separated at the onset of ventricular contraction.