> For the complete documentation index, see [llms.txt](https://thisispiggy.gitbook.io/my-wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://thisispiggy.gitbook.io/my-wiki/01-step-1/cardiology/09-starling.md).

# 09 Starling

## Starling Curve

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/frank%20starling%20curve%20nl,%20left%20and%20right%20shifts,%20causes/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/Y6LgK8U.jpg)

* preload can be either pressure or volume
* the more you load the ventricle with fluid, the more it'll pump 
* allows heart to pump with higher venous return, otherwise blood would pool in venous system

![](https://f001.backblazeb2.com/file/wikiFiles/duLzrRx.jpg)

* shifting to left: at same preload, more stroke volume

![](https://f001.backblazeb2.com/file/wikiFiles/RIIPhBs.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/XP9EEdk.jpg)

* TPR = SVR = peripheral resistance

## Venous Return

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/venous%20return%20curve%20normal/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/NquyyQn.jpg)

* venous return = CO: blood returned to heart = blood pumped out of heart
* X axis could be either venous return or CO
* as CO increases, RAP falls

![](https://f001.backblazeb2.com/file/wikiFiles/qQVAeb7.jpg)

* RAP equal to venous pressure from SVC/IVC 
* Increased CO: pulls more blood out of RV/RA, lowers RA pressure

![](https://f001.backblazeb2.com/file/wikiFiles/NzMwLoN.jpg)

* how actually drawn

![](https://f001.backblazeb2.com/file/wikiFiles/nWOUpMr.jpg)

* MSFP defined by volume in venous system and tone of veins in body
* MSFP = pressure when CO is 0

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/venous%20return%20curve%20shifts/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/w64fBsZ.jpg)

* green: right shift

![](https://f001.backblazeb2.com/file/wikiFiles/eQYxs3d.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/1GdOEOc.jpg)

* increased TPR: same CO leads to lower venous pressure and lower RAP

## Combined Curves

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/combined%20starling,%20venous%20return%20curves/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/512qf2D.jpg)

### HF

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/HF%20combined%20starling%20and%20venous%20return/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/ceU5yqe.jpg)

* lower contractility: shift to right of starling curve
* fluid retention: increased fluid volume, shift venous return curve right
* increased TPR: changes slope of venous return curve

![](https://f001.backblazeb2.com/file/wikiFiles/n4581ov.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/RqylHzG.jpg)

* lower CO and higher RAP

### Hemorrhage

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/hemorrhage%20combined%20curve/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/h4Wi2tn.jpg)

* blood loss: shift venous return left
* TPR up: slope left
* contractility: starling curve up

![](https://f001.backblazeb2.com/file/wikiFiles/wJQZRho.jpg)

* lower CO, lower RAP

### Exercise

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/exercise%20combined%20curve/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/9cnbSDY.jpg)

* venous contraction from sympathetic activation
* venous contraction: move to right
* decreased TPR: slope right
* higher CO in exercise

### Fistula

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/AV%20fistula%20combined%20curve/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/R5nuLXQ.jpg)

* same as exercise 
* high output heart failure

![](https://f001.backblazeb2.com/file/wikiFiles/L8Wnxa7.jpg)

* nl: arteriole connectes arteries and veins. Arteries have high resistance
* AV: bypass from A to V with low resistance
* result: TPR down

### Vasopressors

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/vasopressors%20combined%20curve/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/2NA7cPX.jpg)

[\_](https://github.com/thisispiggy/my-wiki/tree/601ff771dc2fac1318ae8b59435ac8485628fd81/01%20Step%201/Cardiology/ignore/README.md)..

![](https://f001.backblazeb2.com/file/wikiFiles/5gbg6xk.jpg)

![](https://f001.backblazeb2.com/file/wikiFiles/DShIIJt.jpg)


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