Table 3.
Strengths and limitations of individual echo-Doppler variables for diastolic assessment
| Variable | Strength | Limitations |
| Left ventricular (LV) hypertrophy | A good morphologic marker of impaired relaxation | Prone to measurement error; absence of LVH does not guarantee normal relaxation |
| LV ejection fraction | If LVEF is depressed ( < 50%), there is, by definition, impaired LV relaxation present | For patients with preserved LVEF ( ≥ 50%), other markers of LV relaxation are required: e′, LV strain |
| Left atrial volume | Can be used as a “barometer of LV filling pressure” | Can be enlarged in situations where LV filling pressures are normal: atrial fibrillation |
| Mitral inflow (E, A, E/A, DT) | Very flow dependent, so provide “real-time” assessment of cardiac load | Prone to pseudo-normalization; thus, a load-independent measure of LV relaxation (e′, strain) is needed to interpret |
| Tissue Doppler early diastolic relaxation (e′ and E/e′) | Load-independent assessment of LV relaxation (e′); robust data on estimation of LV filling pressure and prognosis (E/e′) | Can be difficult in non-sinus rhythm, or in BBB; prone to spectral broadening; “grey zone” for E/e′ (9–13) |
| Flow Propagation Velocity (Vp) | Can provided reasonable estimated of LV relaxation (Vp) and LV filling pressure (E/Vp) | Not as dependable in patients with preserved LVEF |
| Pulmonary venous Doppler | Very flow dependent, so provide “real-time” assessment of cardiac load; S/D related to mean LA pressure; Ar-A duration to LVEDP | Prone to pseudo-normalization; thus, a load-independent measure of LV relaxation (e′, strain) is needed to interpret; difficult in non-sinus rhythm |
| Pulmonary artery pressure (by peak TR velocity) | Correlates relatively well with elevated LV filling pressure; good negative predictive value | Can be elevated in absence of elevated LV filling pressure: (primary pulmonary hypertension, cor pulmonale) |
| LV speckle strain | Can provide a non-Doppler assessment of LV relaxation; measurable in multiple vectors | Requires high 2D frame rate (40–70 fps), and specific echo equipment and expertise; inter-reader variability can be an issue |
A = late transmitral diastolic velocity; Ar = pulmonary venous atrial reversal; DT = mitral deceleration time; E = early transmitral diastolic velocity; LA = left atrial; TR = tricuspid regurgitation.