Murmur: non-cardiologists are poor at diagnosing systolic murmurs

Clinical bottom line (level 2a)

  1. Cardiologists were good at diagnosing systolic murmurs (unlike non-cardiologists), though they do not agree well about the signs.
  2. Systolic murmurs were common and most were benign.
  3. Aortic stenosis:
    • was diagnosed by effort syncope, a slow rising carotid pulse, a late peak in the murmur and a reduced second heart sounds
    • was ruled out by brachioradial delay, apical-radial delay, no murmur, no radiation to the right carotid, and no fourth heart sound
    • a scoring system helped diagnose aortic stenosis
  4. Mitral regurgitation:
    • is made more likely if the murmur is in the mitral area, the murmur increases with transient arterial occlusion or if a murmur occurs after an acute MI
    • is ruled out if there is no late or pansystolic murmur
    • interns guess the diagnosis of mitral regurgitation
  5. Tricuspid regurgitation:
    • was well diagnosed by cardiologists listening for the murmur
    • was ruled in by an increase in the murmur on sustained abdominal pressure, or on inspiration
    • was ruled out if there is no increase in murmur intensity on inspiration
  6. Hypertrophic cardiomyopathy:
    • was ruled in if murmur intensity decreases on passive leg elevation, or stays the same or decreases on squatting
    • was ruled out if murmur intensity increases on squatting, or stays the same or increases on passive leg elevation
  7. Mitral valve prolapse:
    • was ruled in if a cardiologist hears a systolic click and a murmur, or a click alone
    • was ruled out if a cardiologist hears no click or murmur
    • was poorly diagnosed by non-cardiologists
    • indicates a poor prognosis if the murmur is pansystolic
Etchells et al: Journal of the American Medical Association 1997; 277 (7): 564-571
Expires July 2004

The study

Systematic review of all of
  • Patients: aged 62-100 years old
  • Outcome: diagnosis of murmurs


    • Articles found in English using ?, 1966-1996 (search terms: not detailed )

    Selection criteria: as above
    Appraisal criteria: not detailed
    Articles excluded if:

    it is unclear how many studies were included

    The evidence


    diagnostic test with without LR+
    (95% CI)    		 LR-
    (95% CI)
    effort syncope inf
    (1.3 to inf)     		0.76
    (0.67 to 0.86)
    slow rise of carotid pulse 130
    (33 to 560)     		0.62
    (0.51 to 0.75)
    maximum peak murmur intensity late 101
    (25 to 410)     		0.31
    (0.22 to 0.44)
    decreased intensity/absent second heart sound 50
    (24 to 100)     		0.45
    (0.34 to 0.58)
    fourth heart sound 2.5
    (2.1 to 3.0)     		0.26
    (0.14 to 0.49)
    any murmur 2.4
    (2.2 to 2.7)     		0.0
    (0.0 to 0.13)
    radiation to right carotid 1.4
    (1.3 to 1.5)     		0.10
    (0.13 to 0.40)
    apical-carotid delay inf
    (2.4 to inf)     		0.05
    (0.01 to 0.31)
    brachioradial delay 6.8
    (3.2 to 14)     		0.0
    (0.0 to 0.3)
    mitral regurgitation: murmur in mitral area 3.9
    (3.0 to 5.1)     		0.34
    (0.23 to 0.47)
    mitral regurgitation: late/pansystolic murmur 1.8
    (1.2 to 2.5)     		0.0
    (0.0 to 0.8)
    mitral regurgitation: any murmur following an acute MI 4.7
    (1.3 to 11)     		0.66
    (0.25 to 1.00)
    mitral regurgitation: transient arterial occlusion causing increased murmur intensity 7.5
    (2.5 to 23)     		0.28
    (0.18 to 0.60)
    tricuspid regurgitation: moderate-severe TR diagnosis in patients referred for echocardiogram 10.1
    (5.8 to 18)     		0.41
    (0.24 to 0.70)
    tricuspid regurgitation: increased murmur intensity on inspiration 8.0
    (3.5 to 18)     		0.0
    (0.0 to 0.43)
    tricuspid regurgitation: increased murmur intensity on sustained abdominal pressure inf
    (2.5 to inf)     		0.33
    (0.15 to 0.58)
    hypertrophic cardiomyopathy: decreased murmur intensity on passive leg elevation 8.0
    (3.0 to 21)     		0.22
    (0.06 to 0.77)
    hypertrophic cardiomyopathy: no change or decrease in murmur intensity on squatting 4.5
    (2.3 to 86)     		0.13
    (0.02 to 0.81)
    mitral valve prolapse: systolic click and murmur 19
    (4.6 to 86)     		2.4
    (1.0 to 5.7)
    mitral valve prolapse: systolic click 12
    (5.4 to 25)     		1.3
    (0.7 to 2.2)
    mitral valve prolapse: no ejection click +/- murmur 3.8
    (2.3 to 6.8)
    ( to )
    mitral valve prolapse: murmur only 2.4
    (1.0 to 5.7)     		0.7
    (0.3 to 1.3)
    mitral valve prolapse: no murmur or click 0.04
    (0.02 to 0.11)     		0.53
    (0.23 to 1.2)
    total

    • pre-test probability: young- 5-50% systolic murmurs: 86%+ normal
    • pre-test probability: old- 30-60% systolic murmurs: 44%+ normal
    • precision for cardiologists Kinterobserver:
      • systolic murmur: 0.30
      • grade 2+ murmur: 0.29
      • late pansystolic: 0.74
    • Cardiologist's diagnosis:
      • abnormal murmur: LR (95% CI): inf (14 to inf)
      • possibly abnormal murmur: LR (95% CI): 2.3 (0.7 to 5.9)
      • normal: LR (95% CI): 0.0 (0.0 to 0.4)
    • variable and point score (maximum 14):
      • reduced carotid volume- 2
      • slow rate of rise of carotid pulse- 3
      • murmur loudest at second right intercostal space- 2
      • decreased intensity/absent second heart sound- 3
      • valve calcification- 4
    • aortic stenosis points score:
      • 14: LR (95% CI): inf (0.6 to inf)
      • 10-13: LR (95% CI): 8.0 (1.6 to 46)
      • 7-9: LR (95% CI): 2.7 (1.0 to 8.0)
      • 2-6: LR (95% CI): 0.27 (0.15 to 0.49)
      • 0: LR (95% CI): 0.10 (0.01 to 0.58)
    • mitral regurgitation:
      • detected by interns: LR+ 1.1; LR- 1.0
      • detected by students: LR 4.6; LR- ?
    • mitral valve prolapse:
      • pansystolic murmur: LR (adverse outcome) (95% CI): 5.1 (2.2 to 9.9)
      • no click or murmur: LR (adverse outcome) (95% CI): 0.0 (0.0 to 4.1)
    • adverse outcome: death, stroke, endocarditis, progressive MR requiring surgery

    Comments

    1. Transient arterial occlusion: a blood pressure cuff around both arms simultaneously inflated to 20-40 mmHg >systolic blood pressure. Check murmur intensity 20 seconds later.
    2. Sustained abdominal pressure: patient relaxes and breathes through open mouth. Place palm of hand on midabdomen and push at pressure 20-35 mmHg for 15-30 seconds.
    3. Most papers looking at the performance of cardiologists- non-cardiologists are noticeably less good.

    Citation

    1. Etchells E, Bell C, Robb K, et al: Does this patient have an abnormal systolic murmur?. Journal of the American Medical Association 1997; 277 (7): 564-571
    Contributor: Chris Ball and Musab Hayatli, July 2000
    Reviewer:

    Clinical Question.
    Patient 62-100 years old
    Intervention or Exposure diagnosis
    Outcome murmurs