heart failure

Specialties Cardiac

Published

Could someone please explain to me what happens in heart failure? I am just wondering exactly is the pathophys. behind what is going on so I can understand it better. Thanks!

thanks, those websites help a lot! but i am still a little bit confused about what is going on with the heart to cause this... i have tried reading my book but i get really confused about preload and afterload. could anyone help explain this?

Specializes in CTICU.

In general terms, the heart is pushing against a high blood pressure (afterload) and the muscle wears out and gets weak (low ejection fraction). Because it's big and floppy then, it needs to get a lot of fluid into it (preload) in order to be able to eject the required amount to perfuse the body. Kind of like an old rubber band needs to be stretched further to be able to flick it.

The basic outcome of heart failure is that you cannot pump enough blood to adequately perfused your head, kidneys, peripheries.

Specializes in Public Health, TB.

I have to disagree with high blood pressure causing the muscle to become big and floppy. Actually the muscle become big and hypertrophic, decreasing the volume that the heart can eject. Thus the EF can be normal or high but the heart is not pumping enough to supply the rest of the body (diastolic failure).

For an explanation of pre and afterload, I suggest you look up Starlings' law:

http://www.cvphysiology.com/Cardiac%20Function/CF003.htm

Briefly, the more a ventricle is stretched ( or "loaded") the more it will contract and empty , to a point. When the muscle is damaged and overstretched, it doesn't contract and empty as well. Neuro-hormones like epinephrine, aldosterone, and angiotensin trigger a remodeling of heart muscle so the muscle gets progressively weaker. Thus the treatment of includes decreasing blood volume (diuretics), and blocking epinephine (beta blockers) and angiotensin ( ACE-Is and ARBs).

Specializes in CTICU.
I have to disagree with high blood pressure causing the muscle to become big and floppy. Actually the muscle become big and hypertrophic, decreasing the volume that the heart can eject. Thus the EF can be normal or high but the heart is not pumping enough to supply the rest of the body (diastolic failure).

Well as I said I was giving a very basic explanation. Systolic heart failure is what is generally known as "heart failure" by the beginner. The consequence of either SHF or DHF is that inadequate perfusion is supplied to the body.

Specializes in Public Health, TB.
Well as I said I was giving a very basic explanation. Systolic heart failure is what is generally known as "heart failure" by the beginner. The consequence of either SHF or DHF is that inadequate perfusion is supplied to the body.

Point taken.

2 kinds of heart failure--big, floppy ventricle that can't pump or or big muscular ventricle that can't fill. I just didn't want the OP to get confused.

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