Echocardiogram in Congestive Heart Failure

Echocardiogram in Congestive Heart Failure

Aka: Echocardiogram in Congestive Heart Failure, Echocardiogram in CHF, Echocardiogram in Systolic Dysfunction, Echocardiogram in Diastolic Dysfunction, E-A Wave Ratio, Measurement of Tau

II. Indication

  1. Every patient with Congestive Heart Failure!
  2. Distinguishes
    1. Systolic Dysfunction
    2. Diastolic Dysfunction
  3. Identify underlying valve disease
  4. Identify underlying ischemic heart damage
  5. Quantify Congestive Heart Failure severity

III. Assessment

  1. Chamber size (diastolic and end-systolic dimensions)
    1. Left Ventricular Hypertrophy
    2. Left Atrial Enlargement
  2. Ejection Fraction (EF)
    1. Systolic Dysfunction: EF < 45%
    2. Diastolic Dysfunction (isolated): EF > 50%
    3. Echocardiogram accuracy is +/- 5% at best
  3. Heart Valve Function and dysfunction
  4. Wall thickness and wall motion abnormalities
  5. Parasternal long axis view
    1. Mitral valve leaflet at maximal opening >13 mm distance from septum suggests Ejection Fraction <30%
    2. Ejection fraction can be estimated visually (tilt probe to include cardiac apex)
  6. Parasternal short axis view below mitral valve
    1. Ejection fraction can be estimated visually

IV. Findings: Diastolic Dysfunction

  1. Ejection Fraction >50% (see above)
  2. Abnormal pulmonary venous flow pattern
  3. Measurement of Tau (LV pressure decay)
    1. Assesses left ventricular stiffness
    2. Prolonged isovolemic relaxation time
    3. Prolonged deceleration time
  4. E-A Wave Ratio (Trans-mitral valve blood flow)
    1. Components
      1. E-Wave (LV filling) Peak Flow velocity
      2. A-Wave (atrial contraction) Peak Flow velocity
    2. Interpretation
      1. Normal: 1.5
      2. Early Diastolic Dysfunction: <1.0
      3. Late Diastolic Dysfunction: >2.0

V. Special Problems

  1. Body habitus too large for adequate exam
    1. Nuclear Ventriculogram (MUGA Scan)

VI. Resources

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