Can S3 be present in aortic stenosis?

Can S3 be present in aortic stenosis ? If yes why?

the presence of a third heart sound (S3) can be detected in patients with aortic stenosis, although it’s less common and typically occurs in advanced stages or in specific clinical circumstances.

The S3 heart sound is associated with rapid filling of the ventricle during early diastole. In the context of aortic stenosis, where the aortic valve is narrowed and impedes blood flow from the left ventricle into the aorta, rapid ventricular filling during early diastole may be restricted. This reduced filling can diminish the likelihood of a prominent S3.

However, in certain situations, an S3 can still be heard in aortic stenosis:

  1. Severe Aortic Stenosis with Increased Flow:
  • In severe cases of aortic stenosis, the left ventricle may hypertrophy (enlarge) in response to the increased workload required to pump blood through the narrowed aortic valve.
  • The hypertrophied ventricle may have increased stiffness, resulting in impaired ventricular compliance and a more abrupt diastolic filling phase, potentially producing an audible S3.
  1. Associated Conditions:
  • Patients with aortic stenosis may have concurrent conditions, such as heart failure or volume overload, which can cause increased blood volume and flow into the ventricle during diastole. This increased flow can contribute to the development of an S3.
  1. Differential Diagnoses:
  • It’s important to consider that an audible S3 in a patient with suspected aortic stenosis could also be due to another cardiac pathology, such as mitral regurgitation, ventricular septal defect, or left-to-right shunting.

In summary, while aortic stenosis primarily results in turbulent blood flow across the aortic valve and often reduces the likelihood of an audible S3 due to impaired ventricular filling, certain circumstances, such as severe aortic stenosis with increased flow or associated conditions, can lead to the presence of an S3. Clinical evaluation, including thorough auscultation and diagnostic tests, is essential for accurately identifying and interpreting heart sounds in patients with cardiac conditions like aortic stenosis.