Lars Mølgaard SaxhaugInteresting review of diastolic function grading in critically ill patients, basically arguing for left atrial strain. Some comments follow : https://onlinelibrary.wiley.com/doi/10.1111/echo.15773 #echocardiography #CriticalCare #cardiology
Ejection fraction has been compared to global longitudinal strain repeatedly for prediction of outcomes in diverse settings including #criticalcare and #sepsis . #GLS conclusively outperformes #EF if and only if linearity is assumed. That is, it's a statistical artifact. Having a very low or very high EF is bad, the relationship is U-shaped, no linear. https://doi.org/10.1016/j.chest.2023.01.010
A classic low preload, low afterload, high inotropy septic circulation will increase EF, but since GLS is considerably more sensitive to preload and heart rate, it will rather be decreased just as VTI and stroke volume will. This explains to a large degree I think the linearity for GLS, vs the non-linearity for EF. It does not mean GLS is more usefull or informative!
Segun OlusanyaMuch the same applies to left atrial strain. It's for the most part a composite of left atrial size, and left ventricular long axis function. Left atrial size does not vary much acutely, while left ventricular long axis function is as discussed generally reduced by all unfavourable loading conditions including high afterload and low preload.
A general point here is that a parameter that might reasonably predict left atrial pressure across a population of individuals at rest and stable loading conditions, may not track left atrial pressure when it changes acutely in the individual at all. Across population correlation =/= within individual correlation
Another point is that we use diastolic function and left ventricular filling pressures interchangeably in outpatient echocardiography. We basically assume that if we detect increased filling pressure at rest, or during exercise, that means that patient has diastolic dysfunction of some degree.
Diastolic function and filling pressures cannot be used interchangeably in the acute setting however, as we can have any combination of diastolic function and filling pressures!
Diastolic function and filling pressures cannot be used interchangeably in the acute setting however, as we can have any combination of diastolic function and filling pressures!
What we need in #criticalcareechocardiography is less extrapolation from outpatient populations under normal loading conditions, and more studies evaluating effect in individuals of changing load conditions on these parameteres and how these parameteres are able to track changes in loading conditions and distolic function. My hunch is that as with fluid responsiveness, we will discover that static parameters are useless, dynamic are useful.
@load_dependent great thread Lars!
@load_dependent watch this space for some interesting data around LA size…
@Iceman_ex am I going to have to eat my words? 😂