Cardiac insufficiency

[fernandbteich]

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Hello
I have a question and I hope you can help me.
As far as I know, a cardiac insufficiency is declared when the heart (right or left) cannot pump enough blood to the organs connected to it (be them lungs or other organs). A cardiac insufficiency (right or left), if left untreated, will lead to a CARDIOGENIC shock with hypotension, tachycardia, peripheral ischemia and cyanosis, often followed by death.
I would like to know if what I stated is correct as well as inquire about the causes of cardiac insufficiency.
Logically, I'm thinking of insufficiency following cardiac depletion or overload. I mean if the left heart is "empty" this will lead to a LHI and if it's let's say overloaded with blood, it cannot stretch normally and the cardiac flow will go down hence the insufficiency. Is this correct?
Finally, I'd like to know more about the specific AVF (arterio-venous fistula) case, especially when caused by a trauma. Blood will logically go adrift the pressure gradient from the artery to the vein, causing chronically a right heart overload, therefore a right heart insufficiency due to overload followed by a left heart insufficiency due to volume depletion. Am I thinking the right way?
Any confident answer or reliable source to check, may be well appreciated.
Thanks in advance
Fernand

 

[nickolas]

When heart fails as a pump two problems can occur. Left ventricle: Not enough blood goes to the periphery or blood accumulation in the lungs (pulmonary edema) that cannot be pumped. For reasons that probably have to do with natural selection, when left ventricle fails what is predominant is the pulmonary edema and when the right ventricle fails is edema in the extremities.
Blood accumulation prior to the failing ventricle is the source of the problem.

If the person with failing heart gets treated with diouretics, then symptoms of low output may become predominant.
If the left ventricle is empty, because a failing right ventricle cannot keep up, it is pure right heart failure (and vice versa).

Hope this helps a bit!

 

[fernandbteich]

Thank you mate but it's not really what I am looking for.
Can cardiac insufficiency happen due to depletion (lack of blood in the ventricle) or overload?
Anything related to Starling's law claiming that an extremely tense cardiac fiber cannot contract well (and of course a non-tense fiber will not contract)?
Thank you

 

[nickolas]

Thank you mate but it's not really what I am looking for.
Can cardiac insufficiency happen due to depletion (lack of blood in the ventricle) or overload?
Anything related to Starling's law claiming that an extremely tense cardiac fiber cannot contract well (and of course a non-tense fiber will not contract)?
Thank you

Heart failure is "always" due to overload. Unless you over treat a patient with diuretics (in which case the hypotension is not considered cardiogenic shock)

 

[nickolas]

Heart failure is "always" due to overload. Unless you over treat a patient with diuretics (in which case the hypotension is not considered cardiogenic shock)

I post to correct my previous post.

Heart failure by definition is either:
A) Increased filling pressures. CVP (right ventricle failure) and/or PCWP (left ventricle failure). Volume overload in other words and 80-90% of the patients present this way. The patient is WET and WARM.
B) Decreased cardiac output (low cardiac index) with easy fatique (NOT dyspnea or coughing, that is water on the lungs in volume overload) and cold extremities. About 10-20% of patient have this presentation. The patient is DRY and COLD
C) A combination of A + B. The patient is both WET and COLD.

Now, trauma AVF (arterio-venous fistula) effects depend whether the patient is case A or case B.
In case A there is volume overload on the right ventricle and a danger of a failing right ventricle. Remember the Frank/Starling curve tappers towards the end. More volume load equals more cardiac output but only up to a point; an overloaded ventricle is super streched and cannot pump effectively.
In case B, precious blood supply from the failing left ventricle is lost and the patient is in danger of cardiogenic shock.

Ventricles may differ. You may have isolated elevated CVP for example and a left ventricle with good function for the time being.

Lastly cardiac ultrasound is handy but be carefull with the interpretation. In hypertrophic cardiomyopathy, increasing EF is BAD. It means more hypertrophy which in turn reduces ventricle volume, so even if EF is increased, cardiac output is decreased.
Of course there is diastolic heart failure aka heart failure with preserved EF. The heart is normal on the ultrasound but filling pressures and/or output is compromised. Also EF depends on heart rate (it is normal to have a drop in EF at higher heart rates, rember cardiac output is EF times heart rate).

 

[sanj238]

I post to correct my previous post.

Heart failure by definition is either:
A) Increased filling pressures. CVP (right ventricle failure) and/or PCWP (left ventricle failure). Volume overload in other words and 80-90% of the patients present this way. The patient is WET and WARM.
B) Decreased cardiac output (low cardiac index) with easy fatique (NOT dyspnea or coughing, that is water on the lungs in volume overload) and cold extremities. About 10-20% of patient have this presentation. The patient is DRY and COLD
C) A combination of A + B. The patient is both WET and COLD.

Now, trauma AVF (arterio-venous fistula) effects depend whether the patient is case A or case B.
In case A there is volume overload on the right ventricle and a danger of a failing right ventricle. Remember the Frank/Starling curve tappers towards the end. More volume load equals more cardiac output but only up to a point; an overloaded ventricle is super streched and cannot pump effectively.
In case B, precious blood supply from the failing left ventricle is lost and the patient is in danger of cardiogenic shock.

Ventricles may differ. You may have isolated elevated CVP for example and a left ventricle with good function for the time being.

Lastly cardiac ultrasound is handy but be carefull with the interpretation. In hypertrophic cardiomyopathy, increasing EF is BAD. It means more hypertrophy which in turn reduces ventricle volume, so even if EF is increased, cardiac output is decreased.
Of course there is diastolic heart failure aka heart failure with preserved EF. The heart is normal on the ultrasound but filling pressures and/or output is compromised. Also EF depends on heart rate (it is normal to have a drop in EF at higher heart rates, rember cardiac output is EF times heart rate).

holy cow this post is so MONEY

where did you get this info? Where can I find this stuff specifically the stuff on wet and warm etc. and clinical concepts- easy fatigue v dyspnea etc.

yea yea you can reason it out- but i prefer something to tell me 🙂

 

[nickolas]

You can thank Lynne W Stevenson, MD. See this paper http://content.onlinejacc.org/article.aspx?articleid=1132304#

 

[sanj238]

You can thank Lynne W Stevenson, MD. See this paper http://content.onlinejacc.org/article.aspx?articleid=1132304#

How did you come across this