What is the workup for diastolic dysfunction?

Workup for Diastolic Dysfunction

The comprehensive workup for diastolic dysfunction should include echocardiography with specific Doppler parameters as the primary diagnostic tool, along with natriuretic peptide testing, electrocardiogram, and chest X-ray to establish diagnosis and severity. 1

Initial Diagnostic Evaluation

• Echocardiography: The cornerstone of diastolic dysfunction diagnosis

  • Key parameters to assess:
    • Mitral inflow velocities (E/A ratio)
    • Mitral annular tissue Doppler velocities (e')
    • E/e' ratio (>14 suggests elevated filling pressures)
    • Left atrial volume index (>34 mL/m²)
    • Peak tricuspid regurgitation velocity (>2.8 m/sec)
    • Pulmonary vein velocities (when needed)

• Laboratory tests:

  • Complete blood count
  • Serum electrolytes
  • Serum creatinine
  • Blood glucose
  • Liver function tests
  • Thyroid function (based on clinical findings)
  • Natriuretic peptides (BNP or NT-proBNP) - elevated levels suggest diastolic dysfunction 1

• Electrocardiogram (ECG):

  • While a normal ECG doesn't rule out diastolic dysfunction, it should prompt careful review of the diagnosis
  • Look for evidence of left ventricular hypertrophy, prior myocardial infarction (Q waves), or QRS width >120 ms 1

• Chest X-ray:

  • Assess for cardiomegaly and pulmonary congestion
  • Most valuable when interpreted alongside typical symptoms and abnormal ECG 1

Grading Diastolic Dysfunction

Diastolic dysfunction is typically graded based on echocardiographic findings:

1. Grade I (Mild): Impaired relaxation pattern

   • E/A ratio ≤0.8 with peak E velocity ≤50 cm/sec
   • Normal left atrial pressure at rest 1

2. Grade II (Moderate): Pseudonormal filling pattern

   • E/A ratio appears normal (0.8-2.0)
   • Can be distinguished from normal by reduced e' velocity on tissue Doppler
   • Elevated E/e' ratio (>14) 1

3. Grade III (Severe): Restrictive filling pattern

   • E/A ratio ≥2.0
   • Short E-deceleration time (<160 msec)
   • Elevated left atrial pressure 1

Special Considerations

• Exercise Testing: Consider diastolic stress testing when:

  • Resting echocardiography doesn't explain symptoms of dyspnea or heart failure
  • Patient has Grade I diastolic dysfunction at rest
  • Supine bicycle protocol is preferred for acquisition of Doppler data 1

• Advanced Imaging: Consider in selected cases

  • Cardiac MRI for accurate assessment of left and right ventricular volumes, function, and myocardial characterization 1

Common Pitfalls to Avoid

1. Technical errors in echocardiographic assessment:

   • Improper sample volume placement for tissue Doppler
   • Suboptimal Doppler settings (gain too high/low)
   • Failure to account for age-related changes in diastolic parameters 1

2. Misinterpretation in specific populations:

   • Athletes (may have altered diastolic parameters)
   • Elderly patients (age-related changes in relaxation)
   • Patients with atrial fibrillation (requires different assessment approach)
   • Patients with significant mitral valve disease 1

3. Failure to integrate multiple parameters:

   • Relying on a single measurement rather than using the recommended four key variables
   • Not considering clinical context alongside imaging findings 1

By systematically evaluating these parameters, clinicians can accurately diagnose diastolic dysfunction, determine its severity, and guide appropriate management strategies to improve morbidity, mortality, and quality of life outcomes.