Harvey's Garden

Cardiac auscultation

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Heart murmurs

Heart sounds

Extra (gallop) heart sounds

Tip

  • S3: volume-overloaded
    • Three tree → tree is big and large → ventricle is large
  • S4: pressure-overloaded
    • Four door → door is hard → ventricle is stiff

S3

  • Features
    • Heard just after S2 (after opening of mitral valve)
    • Caused by reverberant sound as blood fills an enlarged LV cavity during passive diastolic filling (i.e. end systolic volume is high)
  • Associated disorders
    • Heart failure with reduced EF
    • High-output states (eg, thyrotoxicosis)
    • Mitral or aortic regurgitation
    • Teens or athletes
      • Hearts are trained to handle more blood

S4

  • Features
    • Heard just before S1 (before closing of mitral valve)
    • Caused by blood striking a stiff LV wall during atrial contraction
      • As the atria contracts in late diastole against a stiffened ventricle, it must increase its force-production, which creates turbulent blood flow.
  • Associated disorders

S2 split

  • Physiological split
    • The sound of aortic valve closure (A2) precedes the sound of pulmonary valve closure (P2) during inspiration
    • Especially pronounced among young individuals
  • Wide split
    • Caused by any condition that increases right ventricular afterload or decreases left ventricular preload
    • Causes
      • Pulmonary hypertension
      • Pulmonary valve stenosis
      • RBBB
  • Fixed split
    • ASD
  • Paradoxical split (reversed split)
    • Audible during expiration but not inspiration
      • Expiration: A2 is heard after P2 during expiration due to delayed closure of the aortic valve (split reversal)
      • Inspiration: the closure of the pulmonary valve is also delayed, resulting in A2 and P2 occurring simultaneously (i.e., a paradoxical decrease in the split during inspiration)
    • Causes
      • Aortic stenosis
      • Left bundle branch block

Jugular venous pressure

Cardiovascular examination

Normal Waveform Components

Abnormal JVP Waveforms

  • Large ‘a’ wave: Increased resistance to right atrial emptying.
    • Causes: Tricuspid stenosis, right ventricular hypertrophy, pulmonary hypertension.
  • Cannon ‘a’ waves: Very large, intermittent ‘a’ waves.
    • Pathophysiology: Right atrium contracts against a closed tricuspid valve (AV dissociation).
    • Causes: Complete heart block (third-degree), ventricular tachycardia, premature ventricular/junctional contractions.
  • Absent ‘a’ wave: No coordinated atrial contraction.
    • Cause: Atrial fibrillation.
  • Large ‘v’ wave (or c-v fusion wave):
    • Pathophysiology: Blood regurgitates into the right atrium during ventricular systole.
    • Cause: Tricuspid regurgitation.
  • Rapid/Steep ‘y’ descent (Friedreich’s sign):
    • Pathophysiology: Rapid, early diastolic filling of a stiff or non-compliant ventricle.
    • Causes: Constrictive pericarditis, restrictive cardiomyopathy.
  • Slow ‘y’ descent:
    • Pathophysiology: Obstruction of right ventricular filling.
    • Causes: Tricuspid stenosis, right atrial myxoma.
  • Blunted/Absent ‘y’ descent:
    • Pathophysiology: Impaired right ventricular filling due to external pressure.
    • Cause: Cardiac tamponade.

Pathology

Common abnormalities of the JVP waveform include:

  • Constrictive pericarditis: elevated JVP (due to increased external atrial pressure) with a prominent x (exaggerated atrial relaxation) and y (early rapid ventricular filling) descent
  • Cardiac tamponade: elevated JVP (due to increased external atrial pressure), a prominent x descent (exaggerated atrial relaxation), and a blunt or absent y descent (minimal ventricular filling)
  • Tricuspid regurgitation: prominent v wave as the blood from the right ventricle regurgitates into the right atrium during ventricular systole (atrial diastole), increasing interatrial pressure and volume
  • Tricuspid stenosis: giant a wave due to high right atrial systolic pressure
  • Atrial septal defect: v wave ≥ a wave due to the left-to-right shunting of blood
  • Third-degree atrioventricular (AV) block: cannon a waves due to the loss of AV synchronization and contraction of the atria against a closed tricuspid valve
  • Atrial fibrillation: absent a waves due to ineffective contraction of the atria
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