How do I calculate right ventricular (RV) and left ventricular (LV) function using transesophageal echocardiography (TEE) spectral Doppler?

TEE Spectral Doppler Assessment of RV and LV Function

Understanding the Limitation of Spectral Doppler for Ventricular Function

Spectral Doppler alone is insufficient for comprehensive assessment of RV and LV function by TEE—you must integrate 2D imaging, volumetric measurements, and tissue Doppler parameters to accurately calculate ventricular function. 1

The question asks specifically about spectral Doppler, but this modality primarily measures blood flow velocities and timing intervals, not direct ventricular function. Here's how to properly use TEE with Doppler techniques:

Left Ventricular Function Assessment by TEE

Primary Method: Volumetric Assessment

• 3D TEE assessment of LV volumes and ejection fraction is recommended over 2D echocardiography, as it provides more accurate and reproducible measurements without geometric assumptions. 1
• Acquire gated 3D data sets from the midesophageal five-chamber view to obtain quantitative measures of LV global and regional function 1
• Use semiautomated quantification software with landmarks at the mitral annulus and LV apex for edge detection 1
• Include trabeculae and papillary muscles within the LV cavity for accurate volume calculations 1

Spectral Doppler-Derived Parameters for LV Function

• LVOT (left ventricular outflow tract) velocity time integral (VTI): Measure pulsed-wave Doppler in the LVOT from the deep transgastric view 1

  • Reduced VTI (<15 cm) indicates reduced LV stroke volume 1
  • Calculate forward stroke volume: SV = LVOT area × LVOT VTI 1

• Mitral inflow pattern: Obtain from midesophageal four-chamber view 1

  • E/A ratio and deceleration time assess diastolic function
  • E velocity ≥1.2 m/s with systolic pulmonary vein flow reversal suggests elevated filling pressures 1

• Tissue Doppler e' velocity: Measure at the mitral annulus 1

  • E/e' ratio estimates LV filling pressures
  • Abnormal E/e' ratio indicates LV diastolic dysfunction 1

Pitfall to Avoid

• Do not rely on single-frame measurements like EROA (effective regurgitant orifice area) when MR is non-holosystolic, as this commonly overestimates severity 1
• Spectral broadening in LVOT Doppler can overestimate forward stroke volume 1

Right Ventricular Function Assessment by TEE

Primary Method: Volumetric and Area-Based Assessment

• RV fractional area change (RVFAC) is the best 2D echocardiographic measure of RV function and correlates most strongly with MRI-derived RV ejection fraction (r=0.80). 2
• Calculate RVFAC from RV-focused four-chamber view: RVFAC (%) = 100 × (RV end-diastolic area - RV end-systolic area) / RV end-diastolic area 1
• Normal RVFAC values and prognostic significance are well-established 1

Spectral Doppler and Tissue Doppler Parameters for RV Function

TAPSE (Tricuspid Annular Plane Systolic Excursion):

• Measure M-mode longitudinal excursion of the tricuspid annulus from the apical approach 1
• TAPSE <16 mm indicates RV systolic dysfunction 1
• Has established prognostic value but is angle-dependent 1
• Can be decreased in PE patients 1

Tissue Doppler S' wave:

• Measure peak systolic velocity of tricuspid annulus by pulsed-wave tissue Doppler 1
• S' <9.5 cm/s indicates RV systolic dysfunction 1
• Easy to perform and reproducible but angle-dependent 1
• More sensitive than TAPSE for detecting early dysfunction 1

RIMP (RV Index of Myocardial Performance / Tei Index):

• Calculate from pulsed Doppler: RIMP = (ICT + IRT) / ET 1
  • ICT = isovolumetric contraction time
  • IRT = isovolumetric relaxation time
  • ET = ejection time
• Has prognostic value and is less affected by heart rate 1
• Tissue Doppler RIMP allows single-beat recording without R-R interval matching 1
• Caution: Unreliable when RA pressure is elevated 1

RV Outflow Tract Doppler:

• Acceleration time (AcT) <60 ms with midsystolic notch suggests pulmonary hypertension 1
• Measure from parasternal short-axis or transgastric views 1

Tricuspid Regurgitation Peak Velocity:

• Peak velocity >3.4 m/s indicates increased RV systolic pressure 1
• Use continuous-wave Doppler aligned with TR jet 1
• Estimate systolic pulmonary artery pressure: sPAP = 4(TR velocity)² + RA pressure 1

Advanced RV Assessment

• RV global longitudinal strain (RVGLS) and RV free wall strain more accurately discriminate RV pressure from volume overload than conventional measures. 3
• RVGLS <-16% predicts RV pressure overload with high accuracy 3
• Strain parameters detect subclinical dysfunction before changes in ejection fraction 4, 3

Critical Clinical Distinctions

RV Pressure vs. Volume Overload:

• Pressure overload (e.g., pulmonary hypertension): Marked decrease in RVFAC, RVGLS, RV-free strain; TAPSE and S' reduced; increased RIMP 3, 5
• Volume overload (e.g., ASD): Larger RV size but relatively preserved TAPSE, S', and normal RIMP 3, 5
• RV pressure overload adversely affects LV function (increased LV Tei index), while RV volume overload typically does not. 5

Practical TEE Protocol Algorithm

1. Start with 2D/3D imaging from midesophageal views to assess overall RV and LV function 1
2. Measure RVFAC from RV-focused four-chamber view as primary RV function parameter 2
3. Obtain tissue Doppler S' at tricuspid annulus for RV longitudinal function 1
4. Measure LVOT VTI for LV stroke volume calculation 1
5. Assess mitral inflow E/A and E/e' for LV diastolic function 1
6. Add TR velocity to estimate pulmonary pressures 1
7. Consider strain imaging when available for early dysfunction detection 4, 3