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Third Heart Sound



  • The third heart sound (S3) is a pathological finding associated with rapid ventricular filling.
    • Interpretation

    • Listen for a gallop rhythm with an extra heart sound just after S2. This is best heard with the bell of the stethoscope at the apex.
    • Causes of Third Heart Sound

    • Normal in children and young adults
    • Left ventricular failure
    • Severe mitral regurgitation
    • Severe aortic regurgitation
    • Constrictive pericarditis
  • Gallop rhythms are so named due to the similarity of their cadence with that of the sound of a horse galloping.
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