Transthoracic Echo

LV Diastolic Function

Definition and Importance
- LV diastolic dysfunction often arises from impaired LV relaxation and increased chamber stiffness.
- Cardiac filling pressures rise due to these dysfunctions, affecting heart function.
- Understanding diastolic function is critical for evaluating heart conditions, particularly heart disease.

Ventricular Relaxation and Compliance
- Diastolic function assesses the ability of ventricles to relax and fill effectively.
- Normal end diastolic pressures correspond to effective filling; increased pressures may suggest dysfunction.

Characteristics
- Failure in ventricles to relax leads to diastolic dysfunction—impacting heart disease symptoms like dyspnea.
- Diastolic dysfunction can precede systolic dysfunction, indicating potential heart issues early.

Key Areas of Focus
- Monitor for impaired relaxation, increased stiffness, and estimate LV filling pressures.
- Identify increased LV diastolic pressure without elevated LVEDV (Left Ventricular End-Diastolic Volume).
- Evaluate heart rhythm, rate, blood pressure, and the presence of mitral valve disease.
- Record LV volume, wall thickness, Doppler patterns, and left atrial volume in reports—particularly in patients with heart failure.

Patient Exclusions for Guidelines
- Not applicable for children or specific diseases (e.g., hypertrophic/restrictive cardiomyopathy, atrial fibrillation).
- Avoid using suboptimal Doppler signals and ensure accurate waveform assessments.

Mitral Inflow
- E-Wave Peak Velocity
  - Measure in the four chamber view.
- A-Wave Peak Velocity
  - Best assessed with lateral swing and posterior tilt.
- EA Ratio
  - Important for evaluating filling patterns.
- E-Wave Deceleration Time (DT)
  - Measure time from peak E down to baseline.
- A-Wave Duration
  - Assess time interval from onset to end of A wave.
Tissue Doppler Imaging (TDI)
- E-Prime Peak Velocity
- E/E-Prime Ratio
  - Measures myocardial movement.
  - Can differentiate between constriction and restriction.
Left Atrial Volume Index (LAVI)
- Calculated as LA volume indexed to body surface area.
- Normal range: less than or equal to 34 ml/m².
- Reflects cumulative effects of elevated LV filling pressure.
Pulmonary Venous Flow
- Assess parameters like S-Wave peak velocity, D-Wave peak velocity, AR duration, and SD ratio.
Peak TR Velocity
- Used to estimate right ventricular systolic pressure and related cardiac pressures. Important for diagnostic accuracy.
Valsalva Maneuver
- Distinguishes between pseudonormal filling and normal filling patterns—EA ratios provide insights based on maneuver's effects.

Normal LVEF Parameters
- Four Key Parameters for Diastolic Dysfunction:
  1. TDI E-Prime Ratio
  2. E/E-Prime Ratio
  3. LV Volume Index
  4. Peak TRV
Positive findings indicate different classifications of diastolic dysfunction, including normal function, inconclusive results, or presence of dysfunction.
In Patients with Reduced LVEF
- Mitral inflow patterns forecast elevated LAP; E wave deceleration time is pivotal.
- Multiple conditions and measurements can assist in determining the degree of diastolic dysfunction and recommend further testing as needed.

Causes of RV Dysfunction
- Links to various diseases and considerations in patients with known RV impairments.
Key Parameters: Tricuspid inflow patterns and tissue Doppler of tricuspid valve annulus.
Interpretation: E/A ratios help identify relaxation issues and potential filling patterns.

Appropriate Measurements
- 2D linear measurements preferred to ensure accuracy over M-Mode due to possible oblique angles.
- Normal ranges for dimensions and pressures help guide appropriate interventions.
- Importance of Practice: Mastery of these concepts is essential in clinical settings, informing proper diagnostic approaches.