The paradox of reduced myocardial shortening in the presence of preserved EF

The paradox of reduced myocardial shortening in the presence of preserved EF is explained mathematically through geometric factors, where EF can be constant for a large variation in shortening if other geometric factors are altered to compensate. Increased wall thickness and/or reduced ED volume augment EF, and therefore can maintain a normal EF despite reduced shortening. EF is quadratically dependent on circumferential shortening and only linearly dependent on longitudinal shortening; hence, EF is less sensitive to a reduction in longitudinal shortening. Our findings suggest that strain measurements reflect systolic function better than EF in patients with preserved EF.



Comparison Between Ejection Fraction and Strain


Editorial Comment V. Fuster MP4

Oliguria is a poor marker for perfusion

Oliguria is an overused parameter to guide resuscitation  and  must  always  be  interpreted  within  the  clinical  context

The 2016 version of  the “Surviving Sepsis Campaign” no longer mentions a UO of  ≥0.5 mL/
 kg/h as a goal of resuscitation. Isolated oliguria with-out  signs  of  vasoplegia,  hypovolemia,  or  low  cardiac output  is  unlikely  to  be  explained  by  a  systemic  hemo-dynamic  cause  and  must  not  evoke  the  administration of additional fluids or vasopressors.

Oliguria should also not  trigger  further  hemodynamic  interventions  in  the clinical  setting  of  established  AKI.

 Oliguria resulting from vasodilatory hypotension  should  preferably  be  treated  with  a vasopressor.  However, a MAP of 80–85 mmHg as target does not seem to be  a  beneficial  strategy,  except  in  patients  with  chronic hypertension.

Reference articles:

Does this critically ill patient with oliguria need more fuids, a vasopressor, or neither?


The Ten Principles behind Arterial Pressure