Shock - hemodynamics | Circulatory System and Disease | NCLEX-RN | Khan Academy

Afterload is not necessarily related to the amount of volume that remains after the squeezing of the heart, it has to do with wall stress that opposes the ejection of blood, or the wall stress at the moment of the ejection.

[@norah3874]

Jesús Ortiz exactly! I was confused by that bit

[@LauraMannes]

I think you need to revisit your definitions of preload and afterload!

[@nhalsey99]

Afterload is the amount of pressure the ventricles must overcome to eject their blood, *not* the amount of blood left in the ventricles after contraction.

[@KJax131]

At 5:30, you said an increased SVR(vasoconstriction) would increase tissue perfusion? I think you are incorrect as a DECREASED SVR (vasodilation) would increase blood flow thus increase tissue perfusion.

[@Creation-l4x]

Frost Rival you are right .. but you think in other way too.. increased SVR means decreased perfusion .. but during shock not every vessels has increased SVR, only the blood vessels to nonvital organs like skin have increased SVR... But the SVR has no effect or decreased , in blood vessels to vital organs .. so that the perfusion is better in vital organs.. this is how I understand.. hope it may help you

[@chadb3525]

CO and SVR are inversely related. That is why CO is high with septic shock, because the low SVR (afterload) creates little impedance for outflow. Afterload and ejection fraction are not the same, which this video claims. The greater the resistance, the harder the heart must work to overcome it. This is a basic principle of how prolonged RAAS activation requires treatment with ACE-Inhibitors. Please redo this video.

[@Creation-l4x]

Chad Backus but he never mentioned that CO and SVR are either directly or indirectly proportional.. he said that perfusion is directly proportional to CO, SVR and O2 content

[@G2H_HellBringer]

I've got a question that isn't related to this topic. What is the hardware and program shown in this video? (the black background, text, etc)

[@playmobilandothers34]

MAP = (CO x SVR) - CVP, not +

[@punies24]

Bb

[@manjitdhami]

Why 2/3 diastolic and 1/3 systolic, why not 1/2 and 1/2, confused

[@rashy28]

Manjit Dhami the heart spends twice as long is diastole as in systole