Heart Sounds Lecture Notes

Introduction

• Presented by Sarah from RegisterNurseRN.com
• Focus: Basics of heart sounds (S1, S2) and extra heart sounds (S3, S4, heart murmurs)
• Practical assessment demonstration in the next video
• Quiz available on website to test knowledge

Purpose of Listening to Heart Sounds

• Assess closure of heart valves
• Provides insights into heart health
• Focus on four valves categorized into:
  • Atrioventricular (AV) valves:
    • Tricuspid
    • Mitral (also known as bicuspid)
  • Semilunar (SL) valves:
    • Aortic
    • Pulmonic

Heart Sounds Explained

• S1 (lub): Closure of tricuspid and mitral valves
• S2 (dub): Closure of aortic and pulmonic valves
• Recognize phases:
  • Diastole: Heart relaxation
  • Systole: Heart contraction

Heart Anatomy and Blood Flow

• Key structures:
  • Superior and inferior vena cava
  • Right and left atrium and ventricles
  • Tricuspid, pulmonic, bicuspid, and aortic valves
  • Pulmonary artery and vein
• Blood flow process:
  • Deoxygenated blood returns via vena cava -> right atrium -> tricuspid valve -> right ventricle
  • During diastole, blood flows passively until AV valves close at S1 (beginning of systole)
  • Ventricle contracts, SL valves open, blood exits to lungs for oxygenation
  • Oxygenated blood returns via pulmonary vein -> left atrium -> bicuspid valve -> left ventricle
  • Blood exits to body through aortic valve during systole

Stethoscope Basics

• Diaphragm: High-pitched sounds (S1, S2, aortic and pulmonic murmurs)
• Bell: Low-pitched sounds (S3, S4, mitral stenosis murmurs)
• Inch chest piece across the chest instead of lifting

Patient Positioning

• Positioning affects sound clarity
• Techniques:
  • Start with patient lying down or sitting
  • For S3, S4, and mitral murmurs, turn patient on left side
  • For aortic and pulmonic valve sounds, have patient sit up and lean forward

Anatomical Landmarks for Auscultation

• Mnemonic: All Patients Take Medicine
  • Aortic valve: 2nd intercostal space, right sternal border
  • Pulmonic valve: 2nd intercostal space, left sternal border
  • Tricuspid valve: 4th intercostal space, left sternal border
  • Mitral valve: 5th intercostal space, mid-clavicular line
• Listen with diaphragm for S1 and S2

Distinguishing S1 and S2

• S1 louder at apex (mitral area)
• S2 louder at base (aortic and pulmonic areas)
• Use EKG R-wave or carotid pulsation to identify S1

Extra Heart Sounds

• S3: Occurs after S2, indicates fluid overload or heart failure
  • Best heard on left side with bell
• S4: Occurs before S1, due to atrial contraction against resistant ventricles

Heart Murmurs

• Turbulent blood flow through heart chambers or valves
• Graded I to VI based on loudness
  • Grade I: Hard to hear
  • Grade VI: Loudest, heard with stethoscope lifted off chest

Conclusion

• Review basics of heart sounds for exams and practice
• Participate in quizzes for reinforcement
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