E/e’ is sometimes used as a proxy for LV End Diastolic Pressure (LVEDP) ¹
Several studies have shown that the pulmonary capillary wedge pressure usually is >20 mm Hg when E/e′ is >15 (e′ from the medial annulus) or >12 (e′ from lateral annulus).²
- If E/e′ is <8, LV filling pressure or pulmonary capillary wedge pressure usually is not elevated.
Variation in the E velocity on mitral inflow (Doppler) is a clue that the LAP is not elevated. By contrast, E velocity that is > 100 cm/s (> 1 m/s) and fixed may indicate an elevated LAP.
- Dr. Oh made note of this in case of patient with AFib where E velocity varied from 80 to 100 cm/s

Views

Mitral Inflow

A4C view with the sampling volume (=) 1 cm distal to the MV annulus or at the leaflet tips during diastole, with a sampling gate of 1 to 3 mm.
E velocity
- peak early diastolic velocity
- The mitral E wave represents the LA-LV gradient during early diastole and thus is preload-dependent. ³
A velocity
- The mitral A wave is the LA-LV gradient during late diastole and is affected by changes in LV diastolic function and LA compliance.³
E/A ratio
Deceleration Time
e’ velocities (using Tissue Doppler)
- e’ measures the peak early velocity of the mitral annulus
- e’ velocity is less sensitive to preload than other measures
  - some may go as far as to say it is preload-independent, i.e. “the e’ velocity never changes,” which is mostly true, but overly simplistic as it’s not 100% insensitive to preload
  - Studies have found e’ to be less preload dependent than other measures of diastolic function, such as mitral inflow and pulmonary vein flow velocities.³
- ⚠️ septal mitral annular e’ measurements may not accurately reflect LV diastolic function in the setting of septal wall motion abnormalities or RV dysfunction ³
E/e’
- reliable estimate of LAP when systolic function is normal ³

Measure the IVC 1-2 cm away from the RA, inner-to-inner
Abnormal IVC dilation if > 2.1 cm
IVC collapsibility
- Ask patient to sniff
- If > 50% collapse → normal
- If < 50% collapse → abnormal
Volume assessment
- Inspiration in normovolemic, spontaneously breathing patients causes negative intrathoracic pressure and a decrease in IVC size. An exaggerated response in IVC collapse occurs in patients in the hypovolemic state during inspiration. ³
Ventilated patients
- Because IVC collapse will not occur in patients on positive pressure ventilation due to inspiration-induced reductions in venous return, it should not be used to monitor RAP in this setting.³

Views include A4C, PSAX, and RV inflow on TTE
- Use the view with the highest velocity signal for serial measurements as this represents the most parallel alignment

e’ velocities might not be as low as expected (compared to sinus rhythm)
- septal E/e’ ≥ 11 as the cutoff in AFib
  - recall that in sinus rhythm, the normal septal E/e’ cutoff is 15, whereas the average E/e’ cutoff is 14
  - 🌟All of the studies for E/e’ assessment in AFib were done using septal E/e’
- In AFib you lack the atrial contraction, so most of the flow of blood into the ventricle is during early diastole (E velocity).
Take advantage of ancillary data when patient is in AFib
- normal RVSP argues against high filling pressures
- abnormal IVC suggest high filling pressures
Dr. Oh mentioned that LA strain has yet to be fully validated in AFib and may not be as useful compared to use in patients with sinus rhythm.

Ommen, S. R., Nishimura, R. A., Appleton, C. P., Miller, F. A., Oh, J. K., Redfield, M. M., & Tajik, A. J. (2000). Clinical Utility of Doppler Echocardiography and Tissue Doppler Imaging in the Estimation of Left Ventricular Filling Pressures. Circulation, 102(15), 1788–1794. https://doi.org/10.1161/01.cir.102.15.1788 ↩
Oh JK, Park SJ, Nagueh SF. Established and novel clinical applications of diastolic function assessment by echocardiography. Circ Cardiovasc Imaging. 2011 Jul;4(4):444-55. doi: 10.1161/CIRCIMAGING.110.961623. PMID: 21772012. ↩
https://www.asecho.org/wp-content/uploads/2015/01/EchoMonitor2015.pdf ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷