Stroke volume of the heart

[pebbles67]

Is stroke volume a reliable clinical variable?

[kenkeith]

Stroke volume is a parameter to determine ejection fraction.  Volume of left venticle after pumping contractions subtracted from volume after filling and that result divided by by filling volume provides the ejection fraction.  There is a margin of error of about  5% plus or minus and in absolute terms there is a variation of stroke volume to help maintain a balance of blood flow of the leftside of the heart with the rightside. The ejection fraction will increase from stroke to stroke based on the dilatation of the LV or decrease when the diameter decreases. The mechanism relates to the Frank/Starling law of physics.

Volume dependence is a reliable parameter regarding the functionality of the left ventricle but the precise volume from stroke to stroke will vary and be less reliable. When I went to ER from a silent heart attack the echo test reports an EF below 29% (13% EF after a few hours after the echo.

Thanks for the question and if you have any followup questions you are welcome to respond.  Take care.