Diastolic Murmurs: Aortic Regurgitation and Mitral Stenosis

Diastolic Murmurs Overview

  • Importance of Diastolic Murmurs
    • Always warrant investigation.
    • Focus on two primary types:
    • Aortic Regurgitation (Aortic Insufficiency)
    • Mitral Stenosis

Aortic Regurgitation (Aortic Insufficiency)

  • Definition: Cardiac valve problem resulting in backward flow of blood into the left ventricle.

  • Cardinal Features (Acronym: LISP T):

    • Location:
    • Best auscultated in the tricuspid area (between pulmonic and tricuspid areas).
    • Intensity:
    • Typically a soft murmur; requires careful listening to discern.
    • The intensity correlates with severity of insufficiency.
    • Shape and Pitch:
    • High-pitched, decrescendo murmur.
    • Sudden onset, starting high and then tapering off.
    • Timing:
    • Begins immediately as diastole starts (post S2).
    • Aortic valve does not close tightly; blood regurgitates into LV.

  • Additional Features:

    • Pulse Pressure:
    • Characterized by a high systolic (e.g., 130 mmHg) and low diastolic blood pressure (e.g., 50 mmHg).
    • Example of pulse pressure calculation:
      extPulsePressure=extSystolic−extDiastolic=130−50=80ext{Pulse Pressure} = ext{Systolic} - ext{Diastolic} = 130 - 50 = 80.
    • Clinical manifestations:
    • Quincke's Pulse: Visible pinkness and to-and-fro motion on nail beds due to wide excursion between systolic and diastolic pressures.
    • Demusset's Sign: Up-and-down head movement with heartbeats.
    • Muller's Sign: Pulsation of the uvula observed during examination.
    • Auscultation of peripheral arteries may reveal bruit patterns indicative of regurgitation.
    • Heart Sounds:
    • Potential for a third heart sound (S3) due to increased diastolic filling pressures, signifying left ventricular overload.

Mitral Stenosis

  • Definition: Narrowing of the mitral valve, often resulting from rheumatic heart disease.

  • Characteristics:

    • Location:
    • Best heard at the apex of the heart.
    • Intensity:
    • Generally a quiet murmur; intensity correlates with disease severity.
    • Shape and Pitch:
    • Low-frequency rumbling sound, akin to the growling of a dog.
    • Described as holodiastolic (occurring throughout diastole).

  • Epidemiology:

    • Less common due to widespread antibiotic use preventing rheumatic fever.

Conclusion

  • Key Points to Remember:
    • Focus on characteristics of diastolic murmurs: especially pulse pressure and specific auscultatory findings for accurate diagnosis.
    • Diagnosis of aortic regurgitation and mitral stenosis hinges on understanding these key features, as they manifest in clinical signs and patient conditions.