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E. Assess LV Function, If Indicated

OBJECTIVE

Select the most appropriate method for the assessment of LV systolic function.

ANNOTATION

LV systolic function may be assessed by contrast angiography at cardiac catheterization, two dimensional echocardiogram, and radionuclide ventriculography. The relative advantages and disadvantages of cardiac ultrasound versus radionuclide ventriculography, are presented in Table 2.

Table 2. Relative Advantages and Disadvantages of Echocardiography and Radionuclide Ventriculography for Assessing LVEF
Test Advantages Disadvantages
Echocardiogram
  • Permits concomitant assessment of valvular disease, ventricular hypertrophy, and left atrial size
  • Can detect pericardial effusion and LV thrombus
  • Usually less expensive and more widely available than radionuclide studies
  • Provides only semi-quantitative estimate of ejection fraction
  • Technically inadequate study, in as many as 18% of patients, and particularly difficult in patients with emphysema
Radionuclide ventriculography
  • More precise, reliable, and quantitative measurement of ejection fraction, compared to echocardiography
  • Better assessment of right ventricular function
  • Limited assessment of valvular function and ventricular hypertrophy
  • Requires venipuncture and radiation exposure
  • Should generally not be used with patients with irregular heart rhythm
Adapted from AHCPR Heart Failure Clinical Practice Guideline, 1995

An echocardiogram is preferable in evaluation of patients who also have physical findings suggestive of valvular heart disease to assess the severity of mitral regurgitation along with assessment of LV systolic function.

If the patient does not have an indication for prompt left heart catheterization and LVEF assessment is not available in the hospital, this test can also be performed on an outpatient basis. Of note, Silver et al., (1994) develo ped a clinical rule to predict LVEF >0.40, with a positive predictive value of 98% in those patients who have ALL of the following characteristics:

  • Interpretive ECG (without left bundle branch block (LBBB), ventricular pacing, or LV with strain pattern)
  • No prior Q-wave MI
  • No history of CHF
  • Index MI which is not a Q-wave anterior infarction