Advanced Physical Diagnosis
  • Techniques
• 1st & 2nd Heart Sounds
• 2nd & 3rd Heart Sounds
• Clicks and Snaps
• Murmurs
• Rubs
  • Demonstrations
Associated Evaluations
  • Patient HX
  • Physical Exam
  • Laboratory & Imaging
Differential Dx
Evidence Base
• Accuracy in Diagnosis of Systolic Murmurs
• Accuracy in Diagnosis of Diastolic Murmurs
• Accuracy in Diagnosis of CHF
Teaching Tips
[Skill Modules >> Heart Sounds & Murmurs >> Techniques ]

Techniques: Heart Sounds & Murmurs

1st & 2nd Heart Sounds

Click to hear Split S2 extra heart sound.

Note: The first heart sound can usually be heard easily with both the bell and the diaphragm but the diaphragm is invaluable for analyzing the second heart sound, with the stethoscope usually best placed at the midleft sternal edge.

Diagram of S3 S4 heart sounds during systole and diastole.

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First Heart Sound
Loud Heart Sound
  • Hyperdynamic (fever, exercise)
  • Mitral stenosis
  • Atrial myxoma (rare)
Soft First Sound
  • Low cardiac output (rest, heart failure)
  • Tachycardia
  • Severe mitral reflux (caused by destruction of valve)
Variable Intensity of First Sound
  • Atrial fibrillation
  • Complete heart block

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Second Heart Sound

Audible expiratory splitting means > 30 msec difference in the timing of the aortic (A2) and pulmonic (P2) components of the second heart sound.

  • Splitting of S2 is best heard over the 2nd left intercostal space
  • The normal P2 is often softer than A2 and rarely audible at apex
    • Differential Diagnosis of P2 audible at apex
      • Significant pulmonary hypertension
      • Atrial septal defect
  • Findings should be present in both upright and supine positions: normal subjects may have expiratory splitting when recumbent that disappears when upright.
Split S2
Type Inspiration Expiration Cause
Normal or physiologic normal inspiration graph expiration graph  
Wide, fixed splitting inspriation graph expiration graph Atrial septal defect
Wide split, varies with inspiration inspiration graph expiration graph Pulmonary stenosis, RBBB
Paradoxical splitting inspiration graph expiration graph Hypertrophic cardiomyopathy
Loud Aortic Component of Second Sound
  • Systemic hypertension
  • Dilated aortic root
Soft Aortic Component of Second Sound
  • Calcific aortic stenosis
Loud Pulmonary Component of Second Sound
  • Pulmonary hypertension

Proceed to the next technique

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