Heart Sounds – Murmurs

Murmur: a low, indistinct sound. In terms of medicine, it is the sound produced due to turbulent flow within the heart and great vessels. They are described and named in relation to the normal heart sounds, location, and quality. (https://epomedicine.com/medical-students/heart-sounds-clinically-explained/)

normal heart sounds

Conditions where murmur may be heard:

  • Pathological Heart Valve – Rheumatic Heart Disease, Degenerative Valves.
  • Abnormal Communications of the Heart – Defects of Septum, PDA.

A heart murmur may always not be indicative of a structural abnormality. In situations causing hyper-dynamic circulation turbulence is created across the valves causing an INNOCENT MURMUR.

murmur types
 

Incomplete Opening

Incomplete Closure

 

Stenosis

Regurgitation/Insufficiency

A-V Valve

Diastolic Murmur

Systolic Murmur

Outflow Valve

Systolic Murmur

Diastolic Murmur

Table. 1 Timing of Murmurs in Valvular Disorders.

Location of the Murmur best heard: Towards the direction of the flow of blood. (In case of stenosis)

@-Intercostal Space, %-Mid Clavicular Line, *-Rheumatic Heart Disease, #-Mitral Valve Prolapse, $-Infective Endocarditis, **-Right Ventricular Dilation, ***-Congenital Heart Disease, ^^-Pulmonary Hypertension

Table. 2 Types of Valvular disorders.

systolic murmurs
diastolic murmurs

Grade of Murmur

Description

1/6

Faint, audible only on special manoeuvres/positions over a specific localization

2/6

Soft

3/6

Loud, without thrill

4/6

Loud, with thrill

5/6

Very Loud, with thrill, heard when stethoscope is partially off the chest

6/6

Very Loud, with thrill, heard without stethoscope

  • A systolic murmur from grade of 3/6 is considered significant.
  • A diastolic murmur of any grade is significant and organic. (Diastolic Murmurs are graded into 4).

Table . 6 Grades of Murmurs

Special Manoeuvres

Effect on Murmurs

Inspiration

(Increased Venous Return)

Increase – Right Sided Murmur

Expiration

(Increased Afterload)

Increase – Left Sided Murmur

Hand Grip

(Increased Afterload)

Increase – Left Sided Murmur

Decrease – HOCM, MVP, Aortic Stenosis

Valsalva or Stand

(Decreased Preload, Increased Afterload)

Increase – HOCM, MVP

Decrease – Most murmurs

Squat

(Increased Preload, Increased Afterload)

Increase – AS, MR, VSD

Decrease – HOCM, MVP

Table. 7 Variations in Loudness based on special manoeuvres.

Condition

Eponym

Tricuspid Regurgitation

Carvallo Murmur

Innocent Murmur

Still’s Murmur

Ventricular Septal Defect

Roger’s Murmur

Aortic Regurgitation

Austin Flint Murmur

Pulmonary Regurgitation

Graham Steell Murmur

Rheumatic Heart Disease – Mitral Stenosis

Carry Comb’s Murmur

Patent Ductus Arteriosus

Gibson Murmur

Table. 8 Murmurs with Eponyms.

References:

  1. Harrison’s Principles of Internal Medicine, 20th Edition.
  2. Bates’ Guide to Physical Examination and History Taking, 10th Edition.
  3. Hutchinson’s Clinical Methods, 23rd Edition.
  4. First Aid for USMLE Step 1, 2019.

Leave a Reply

Your email address will not be published. Required fields are marked *