Anyone heard of Diastolic BP being higher than Systolic???

allnurses Guide · Feb 27, 2010

Thank you for your reply, ghillbert...but I'm going to explain it in a little more detail so that it does make sense...
"This makes no sense. Flow = delta P/R."...this is particularly true in the world of fluid mechanics...where diameters of supply lines and return lines do not vary...pressure of the system is provided by one source...that being a pump or other means that is forcing more fluid into the fixed lines...where resistance is the primary source of pressure. However, if there were a period of "rest" for this type of pump...there would be a pressure drop to zero because the source had been severed. This is not the case of our vascular system...our diastolic pressure does not drop to zero...meaning that pressure is not being applied by resistance but rather the displacement of volume in the system by the constriction of vessels etc...this is what fills the heart during the rest cycle. The equation is right...flow is determined by delta p/r...but it is not the entire equation in the case of the vascular system due to its changing ability of volume.

Sorry still doesn't make sense - even when the heart is at rest, there would not be a diastolic pressure of zero because there isn't suddenly NO resistance. Resistance is not the ONLY factor in working out blood pressure, but it is one and you will not convince me otherwise. I have a science degree and have done plenty of CFD in my time too.

motion+e · Feb 28, 2010

Yes...ghillbert...there is resistance...but what I am trying to express is that this has become the primary focus of explaining BP...during the diastolic cycle we are seeing pressure being applied by another source...this being the constriction of the vessels etc...this would be the resistance that the systolic cycle would have to overcome. The resistance in the diastolic cycle would be the amount of energy it takes for the constriction of the vessels to fill the chamber...yes, there is your restriction. What I am getting at is that simply stating that restriction is what causes blood pressure fails to explain the sources of the energy being exerted into the system to build against this restriction. If you were a fluid mechanical specialist...this would be confusing in that when the heart is at rest...the pressure in the system would fall to zero...because most explanations fail to explain that the constriction...which is a very precise displacement of blood volume...it is calibrated for precision timing and volume. Restriction should be in the third order of the explanation and not immediately following...to cover the sources of energy input, first and foremost, that in turn build up the energy via your restriction...which is the end result.

The fact that the explanation goes further to say that the systolic cycles take advantage of the elasticity of the vessels by taking up some of the force of this cycle by expanding said vessels is misleading as well. Such a system that was entirely dependent on elasticity would be unpredictable and more than likely eventually stretch in a way to lose its form. The fact is that the systolic cycle pressure itself would not have the force available to cause such an expansion in these constricted vessels without utilizing a massive amount of energy that could potentially damage vessels by forcing them open...noradrenaline regulates the dilation and conserves on how hard the heart must work...because there is a precise volume that each vessel can expand to regulate proper flow in the diastolic cycle. The constriction we see is not a weak source like the way it is explained...and if the constriction begins to take place before the valve can open that allows the heart to fill...even though this may be milliseconds...can cause a spike in diastolic pressure that could potentially surpass that of the systolic cycle that had fed it and there lies the possibility of something to rupture...like an aneurysm. This highly regulated constriction and dilation is not simply the rubber band method that is fed to us...this is what I was trying to stress...and yes, perhaps became a little reckless by saying that restriction should fall out of the explanation...but part of the reason that I wanted to set aside restriction at the forefront is simply because it will really become confusing in my explanation of reversing the effects of a stroke...which I am not going to do here as I think I have more people that would like to down my plane rather than try to understand what I am trying to get at. Thank you again for your reply, ghillbert.

HmarieD · Mar 1, 2010

motion+e:

I am just curious... what do you do for a living?

motion+e · Mar 6, 2010

Well, I'm not a nurse...so I think I chose the wrong site. However, if you are still curious...I have engineered the first power system that requires absolutely no fuel or charge...it is self sustaining...there are no emissions...it is more powerful than the conventional combustion engine...faster...it is the heart of superman...and one day soon you will have it in all your automobiles. :)

As far as medical or biology...that is a little complex to explain. After losing someone that I loved...I vowed to change the outcome for others...so they would not have to go through that in which I had endured. I currently have resolved issues with Multiple Sclerosis, Cancer, Autism, and others. Why do you ask?

Penelope_Pitstop, BSN, RN · Mar 7, 2010

.it is the heart of superman

Did I read that correctly?

No, I couldn't have. What was in that Crystal Light I just drank?

motion+e · Mar 7, 2010

LOL! Oh...so much hostility here...

Yes, CamaroNurse...the heart of Superman...as in it will eliminate emissions and allow children to breathe cleaner air in cities polluted with smog...the fact that it is stronger and faster than the engine you have in that camaro of yours...it is the heart of Superman in a mechanical sense.

Penelope_Pitstop, BSN, RN · Mar 10, 2010

LOL! Oh...so much hostility here...
Yes, CamaroNurse...the heart of Superman...as in it will eliminate emissions and allow children to breathe cleaner air in cities polluted with smog...the fact that it is stronger and faster than the engine you have in that camaro of yours...it is the heart of Superman in a mechanical sense.

Not being hostile, just being funny, because I had to read that about three times before I realized that you were serious. And I wanted to make fun, yes. But no hostility!

And will it make the same noise as the 400+ horses under my hood? Just curious. :)

Otessa, BSN, RN · Mar 10, 2010

never heard of that...

Junebugfairy · Mar 10, 2010

did i read that correctly?
no, i couldn't have. what was in that crystal light i just drank?

:lol2:

if it's the same thing that is in my diet pepsi, damn that must be some good stuff..

motion+e · Mar 11, 2010

No...unfortunately it will lack the rumble of the thunder of your 400+ HP...it was originally designed for military applications...it runs silent...but has been downsized for the commercial auto industry. I know the importance of that rumble though...I have two vettes and there is nothing like hearing the throttle wide open or for them to just sit there and have that echoing idle.

Penelope_Pitstop, BSN, RN · Mar 11, 2010

No...unfortunately it will lack the rumble of the thunder of your 400+ HP...it was originally designed for military applications...it runs silent...but has been downsized for the commercial auto industry. I know the importance of that rumble though...I have two vettes and there is nothing like hearing the throttle wide open or for them to just sit there and have that echoing idle.

Then sadly I'm not interested at present. Maybe when I'm older and more responsible? :)

AirforceRN, RN · Mar 11, 2010

I'm going to hijack this already hijacked thread for a moment.

What makes someone a "Specialist?" Is it simply working on a specific ward or is it being a subject matter expert in a specific area? I've so often seen members taglines include four or five "Nursing Specialty" areas yet only 1 or 2 years of nursing experience.

The reason I ask (and I don't intend to be mean, just honest) is the OP states that she/he is a Critical Care Specialist, yet is asking questions about the most fundamental of nursing concepts. I wonder if we should change the tagline to "Area currently working" Just a thought.