Heart murmurs

Background

Phonocardiograms of common cardiac murmurs.

• Defined as a blowing, whooshing, or rasping sound heard during the cardiac cycle.
• Typically caused by turbulent blood flow.

Clinical Features

• Murmur on cardiac auscultation.

Region	Location	Heart Valve Association
Aortic	2nd right intercostal space	Aortic valve
Pulmonic	2nd left intercostal spaces	Pulmonic valve
Tricuspid	4th left intercostal space	Tricuspid valve
Mitral	5th left mid-clavicular intercostal space	Mitral valve

Differential Diagnosis

Valvular Emergencies

• Mitral stenosis
• Mitral regurgitation
  • Mitral valve prolapse
• Aortic stenosis
• Aortic regurgitation

Evaluation

By Abnormal Lesion

• Aortic Stenosis
  • Systolic murmur heard best in the aortic area; rarely at apex
  • Crescendo-decrescendo, radiates to carotids
  • A2 decreased
  • Paradoxical splitting of S2; narrow pulse pressure
  • Pulsus parvus et tardus
• Aortic Insufficiency
  • Diastolic blowing murmur heard at left sternal border in 3rd and 4th interspace
  • Wide pulse pressure
  • Quincke's sign (capillary pulsations at fingertips), DeMusset's sign (bobbing head), Muller's sign (pulsing uvula), and Corrigan's pulse (water hammer)
  • Pistol shot sounds
• Pulmonic stenosis
  • Systolic murmur heard in pulmonic area, transmitted to back and neck
  • A2 is decreased, P2 is delayed, and RVH with parasternal lift
• Pulmonic insufficiency
  • High pitched diastolic murmur; heard in pulmonic area; decrescendo; RVH
• Mitral Stenosis
  • Low rumbling diastolic murmur heard best at apex with bell
  • Opening snap sometimes present worse with closer to S2
  • Loud S1
  • Associated with left atrial dilation
  • Can hear presystolic sound confused with systolic murmur
• Mitral Insufficiency
  • Loud, holosystolic, high-pitched, heard best at apex and transmitted to axilla
  • Soft S1
  • Severity gauged by s3, rumble.
  • Paradoxical splitting

Specific Sounds

• Gallavardin Effect
  • AS sounds like MR - high frequency vibrations to the apex through a calcific AV
• Austin-Flint
  • MS sounds like AR - Soft, rumbling murmur, likely due to functional mitral valve stenosis as the backflow of blood from the aorta presses on anterior leaflet of MV
• Parodoxical S2
  • Splittin during expiration and goes away during inspiration
  • Secondary to inc left sided volume; AS, HOCM
• Wide S2
  • secondary to Inc right sided volume; PE, ASD, VSD, Pulmonic stenosis
• S3
  • AKA ventricular gallop produced during passive LV filling when blood strikes a compliant LV; CHF, Inc Vol, CAD, benign in youth, train athletes
• S4
  • AKA atrial gallop produced when blood is forced into a stiff/hypertrophic ventricle ;MI, hypertension, restrictive cardiomyopathy

Diagnostic Maneuvers

• Valsalva
  • Increases thoracic pressure and lowers preload; then then decreased CO and afterload
  • Increases murmur in MP & HOCM
  • With release: right heart murmurs return first
• Hand grip
  • Increases HR + CO
  • Increases murmur in MR, MS, AR
  • Decreases murmur in AS and HOCM
• Squatting
  • Increased venous return
  • Delays MP click
• Standing
  • Dec in both right & left venous return & SV
  • Decreases murmur of PS, AS, AR, TR, VSD
  • Increases murmur of HOCM
• Inspiration
  • Increases right sided venous return while decreasing left sided return
  • Increases S2 splitting with P2 further from A2
  • Increases in right sided S3 & S4
  • Increases TS opening snap & murmur, PR, TR
  • Decreases MS opening snap, MVP murmur

See Also

• Valvular emergencies
• Innocent Murmurs (Peds)