How to describe Heart Murmur

A heart murmur is produced by turbulent flow across an abnormal valve, septal defect or outflow obstruction, or by increased volume or velocity of flow through normal value. The cause of murmur can be summarized as

1. Due to increased blood flow from a normal or abnormal orifice
2. Through a narrowed orifice to a dilated chamber
3. Backflow flow through an incompetent valve

Types of Heart Murmur

• Innocent murmur:
  • Always systolic & without evidence of physiological/structural abnormalities.
• Functional murmur:
  • Associated with physiological alterations such as
    • High cardiac output states like exercise,
    • Anemia,
    • Hyperthyroidism
    • Increased blood volume associated with pregnancy.
• Pathologic murmur:
  • Caused by structural abnormalities in valves or chambers: Stenosis, regurgitation,

Describing a Heart Murmur

Timing of Heart Murmur

• Systolic:
  • Heard during systole (between S1 and S2 heart sound)
  • If possible note: Early, Late or Pan
• Diastolic:
  • Heard during diastole (between S2 and S1 heart sound)
  • If possible note: Early, Late or mid-diastolic
• Continuous:
  • Heard in both systole and diastole

Shape/Pattern of Cardiac murmur

• Crescendo/Decrescendo
  • Diamond-shaped murmur; ejection type murmur
  • Primary causes: Stenotic valves
• Holosystolic
  • Pansystolic murmur
• Decrescendo
  • Primary causes: Aortic and pulmonic regurgitation, Mitral and tricuspid stenosis
    

Murmur Characteristics

Quality of Murmur

• Sound
• Musical
• Blowing
• Harsh
• Rumbling

Pitch of murmur

• High
• Medium
• Low
• Loud or soft

Location

• Area of maximal intensity like aortic, tricuspid,pulmonary area, mitral area.

Radiation

• May be heard in another place on precordium or neck, back or axilla

Freeman and Levine Grading of Intensity of Heart Murmur

• Grade 1 – Very faint, heard only after the listener has “tuned in;” may not be heard in all positions
• Grade 2 – Quiet, but heard immediately after placing the stethoscope on the chest
• Grade 3 – Moderately loud
• Grade 4 – Loud, with a palpable thrill
• Grade 5 – Very loud, with thrill. May be heard when a stethoscope is partly off the chest
• Grade 6 – Very loud, with thrill. May be heard with stethoscope just removed from and not touching the skin.

Effect of Maneuvers on Heart Murmur

• Inspiration (Increase venous return to right atrium)
  • Increase intensity of right heart sounds
• Handgrip (Increase afterload)
  • Increase the intensity of MR, AR, and VSD murmurs
  • Decrease intensity of hypertrophic cardiomyopathy and AS murmurs
  • MVP: later onset of click/murmur
• Valsalva (phase II), standing up (increase preload)
  • Increase the intensity of most murmurs (including AS)
  • Decrease intensity of hypertrophic cardiomyopathy murmur
  • MVP: earlier onset of click/murmur
• Rapid squatting (increased venous return, increase preload, increase afterload)
  • Increase intensity of hypertrophic cardiomyopathy murmur
  • Decrease intensity of MR, AR, and VSD murmurs
  • MVP: later onset of click/murmur

Differential Diagnosis of Continuous murmur and Holosystolic Murmur

Read More about Valvular Heart Disease

1. Aortic Regurgitation Murmur
2. Tricuspid Regurgitation Murmur
3. Mitral Valve Prolapse Murmur
4. Mitral Regurgitation Murmur
5. Mitral Stenosis Murmur

Know about Changing murmur

These are the murmurs which change their character or intensity from time to time, e.g.,

1. Infective endocarditis,
2. Atrial myxomas, and
3. Atrial thrombus.

Referenes

1. https://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=cm&part=A746