Murmur is an auscultatable sound caused by turbulent flow of blood, caused by stenosis (i.e. restriction of heart valve opening) or regurgitation (i.e. allowing backflow of blood through an incompetent valve that incompletely closses). This can occur within or outside the heart. Murmurs can be physiological (benign) or pathological (abnormal).

HS is shorthand for heart sounds. HSDNM is shorthand for Heart sounds dual, no murmurs. 0m or 0 murmurs (with the 0 superscripted) is shorthand for no murmurs.

• Systolic murmurs, which occur after S1. As the S/L valves are open, and the A/V valves are closed, it can be caused by:
  • S/L stenosis, including:
    • Aortic valve stenosis
    • Pulmonary valve stenosis
  • A/V regurgitation, including:
    • Tricuspid valve regurgitation
    • ​​Mitral valve regurgitation
• Diastolic murmurs, which occur after S2. As the A/V valves are open, and the S/L valves are closed, it can be caused by:
  • A/V stenosis, including:
    • Tricuspid valve stenosis
    • Mitral valve stenosis
  • S/L regurgitation, including:
    • Aortic valve regurgitation
    • Pulmonary valve regurgitation, which is a diastolic decrescendo murmur best heard at the left lower sternal border
• Continuous murmurs

The region where a heart murmur can be best heard roughly reflects a specific part of the heart, including:

• Aortic region, at the RHS 2nd intercostal space parasternal
• Pulmonic region, at the LHS 2nd intercostal space parasternal
• Tricuspid region, at the LHS 4/5th intercostal space parasternal
• Mitral region (aka apex), at the LHS 5th intercostal space mid-clavicular. It is known as the "apex" as it correlates with the apex of the heart

Source: Pinimg

Murmurs will radiate generally in the direction of blood flow.

• Heart sounds
• Aortic stenosis (most common)
• Mitral regurgitation (most common)