systolic murmur

Classification

• graded I to VI

Etiology

• aortic stenosis best heard at right upper sternal border
• mitral regurgitation best heard at cardiac apex
• ventricular septal defect
• mitral valve prolapse
• hypertrophic obstructive cardiomyopathy best heard at left lower sternal border
• bicuspid aortic valve (without aortic stenosis)
  • most common congenital heart defect
  • systolic ejection click
  • early diastolic murmur due to aortic regurgitation common
  • murmur does not vary with respiration or valsalva maneuver
• right-sided systolic murmurs
  • tricuspid regurgitation
    • jugular venous distension increases with Valsalva maneuver
    • pansystolic murmur at the left lower sternal border
    • murmur increases during inspiration
  • pulmonic stenosis (valvular, sub- & supravalvular)
    • pulmonic valvular stenosis
      • mid- to late-peaking crescendo-decrescendo systolic murmur
      • heard best at the upper left sternal border (2nd left intercostal space)
• innocent murmurs may appear to be systolic murmurs*
  • heart murmurs of pregnancy
    • mammary souffle
    • result from increased intravascular volume
• other
  • atrial septal defect: pulmonary mid-systolic flow murmur
  • coarctation of the aorta: systolic murmur over the left chest

* patent ductus arteriosus causes a continuous murmur that envelops S2

Clinical manifestations

• response to maneuvers: (Decrease (D) or Increase (I) in murmur)

quality	etiology	valsalva	hand grip	squat	stand
cres-decres*	AS*	D	D	I	D
holosystolic	MR*	D	I	I	D
holosystolic	VSD*	D	I	I	D
after-late-click*	MVP*	D*	D	D	I ??
h-cres-decres-h@a*	HOC*	I	D	D	I

* cres-decres: crescendo-decrescendo

* AS: aortic stenosis

* MR: mitral regurgitation

* VSD: ventricular septal defect

* MVP: mitral valve prolapse

* after-late-click: late systolic murmur follows click

* h-cres-decres-h@a: harsh, crescendo-decrescendo @ left sternal border, holosystolic @ apex

* HOC: hypertrophic obstructive cardiomyopathy

* ref indicates murmur of mitral valve prolapse increases with valsalva maneuver

• response to inspiration
  • pulmonary stenosis: murmur increases during inspiration
• holosystolic murmur engulfs heart sounds S1 & S2

* innocent murmurs:

• patient is asymptomatic
• typically midsystolic, located at base of heart, grade 1-3/6 without radiation, normal splitting of S2, soft S3 may be present
• a Still murmur is a short, vibratory, grade 1-3, midsystolic murmur of low-pitch
  • best heard at the left sternal border
  • occasionally radiates to the cardiac apex
  • loudest with the patient supine
  • diminished in intensity when the patient sits or stands up (supine -> sitting or standing diminishes venous return to the heart)
  • no further testing indicated
• heart murmurs of pregnancy (mammary souffle)
  • continuous murmur
  • may mimic valvular heart disease
  • increased P2, S3
  • early peaking systolic murmur over the left sternal border
  • S4 >= 3/6 in intensity & fixed S2 are signs of serious cardiac disease

Diagnostic procedures

• transthoracic echocardiogram
  • indications:
    • grade 3/6 or greater
    • late or holosystolic murmur
    • symtomatic patients
  • not indicated for innocent murmur
• transesophageal echocardiogram
  • improved imaging quality, especially for mitral valve

Management

• mild midsystolic murmurs are usually benign & warrant no further testing

More general terms

• heart murmur

More specific terms

• innocent murmur

Additional terms

• handgrip
• Valsalva maneuver