Which conditions can be associated with a soft S1?
Other than calcific mitral stenosis, a soft S1 is usually heard in either early closure of the mitral valve (aortic
regurgitation) or late closure (prolonged P-R interval). Alternatively, a soft or absent S1 can result from
inadequate left ventricular contraction because of congestive heart failure, myocardial infarction, or left bundle branch block (where the left ventricle not only contracts ineffectively, but also late, with M1 following
T1; “M” for mitral and “T” for tricuspid).
Other than calcific mitral stenosis, a soft S1 is usually heard in either early closure of the mitral valve (aortic
regurgitation) or late closure (prolonged P-R interval). Alternatively, a soft or absent S1 can result from
inadequate left ventricular contraction because of congestive heart failure, myocardial infarction, or left bundle branch block (where the left ventricle not only contracts ineffectively, but also late, with M1 following
T1; “M” for mitral and “T” for tricuspid).