Hypokalemia: Causes, Symptoms, Effects on the Heart, Pathophysiology, Animation.
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- Опубліковано 10 вер 2024
- How hypokalemia causes tachycardia; how it affects resting membrane potential. Electrolytes disorders.
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The ratio of INTRAcellular to EXTRAcellular potassium is important for generation of action potentials and is essential for normal functions of neurons, skeletal muscles and cardiac muscles. This is why potassium levels in the blood are strictly regulated within a narrow range between 3.5 and 5mmol/L. As the normal daily dietary intake of potassium varies widely and can be as much as 100mmol a day, the body must keep blood potassium levels within the normal limits. This is achieved by 2 mechanisms:
- Excretion of potassium through the kidneys and intestines
- Shifting of potassium from the extracellular fluid into the cells by the sodium/potassium pump. The pump is mainly regulated by hormones such as insulin and catecholamines.
Hypokalemia is defined as a serum potassium concentration LOWER than 3.5 mmol/L. Hypokalemia may result from INCREASED excretion, INadequate intake or shift of potassium from the extracellular fluid into the cells. Most commonly, hypokalemia is caused by excessive loss of potassium in the urine, from the GI tract, or skin. The cause is usually apparent by the patient’s history of predisposing diseases or medication. Urine potassium levels are measured to differentiate between RENAL and NON-renal causes. Symptoms may include muscle weakness, cramping, tremor, intestinal obstruction, hypotension, respiratory depression and abnormal heart rhythms.
As potassium levels DEcrease in the EXTRAcellular space, the MAGNITUDE of the potassium gradient across the cell membrane is INCREASED, causing hyperpolarization. This moves the membrane voltage FURTHER from the threshold, and a GREATER than normal stimulus is required to generate an action potential. The result is a REDUCED excitability or responsiveness of the neurons and muscles. In the heart, however, HYPER-excitability is observed. This is because HYPER-polarization ENHANCES the “FUNNY” currents in cardiac pacemaker cells, resulting in a FASTER phase 4 depolarization and thus a FASTER heart rate. The effect is greatest in Purkinje fibers as these are more sensitive to potassium levels, as compared to the SA node. Increased automaticity of Purkinje fibers may lead to the development of one or more ECTOPIC pacemaker sites in the ventricles, causing ventricular premature beats, tachycardia and fibrillation.
Reduced extracellular potassium also inhibits the activity of some potassium channels, and thus DELAYS ventricular repolarization. As hypokalemia becomes more severe, especially in patients with other heart conditions, the inward current may exceed the OUTward current, resulting in early afterdepolarization and consequently extra heartbeats. Prolonged repolarization may also promote re-entrant arrhythmias.
Early ECG changes in hypokalemia are mainly due to delayed ventricular repolarization. These include flattening or inversion of T wave, increasingly prominent U wave, ST-segment depression, and prolonged QU interval.
Hypokalemia-induced arrhythmias require immediate potassium replacement. Oral administration is safer but may not be effective in severe cases. If potassium infusion is indicated, continuous cardiac monitoring and hourly serum potassium determinations must be performed to avoid HYPERkalemia complications.
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i swear I am coming back every 3 months to find out how the hypocalemia affects the heart cuz everytime I forget it - its a vicious circle:/
Same bro
Thank god so I’m normal! 😭
Same bro😭😭😭😭😭
Same
5 minutes and you have everything! Thank you!
remedy for copinf hypokalemia
The first part of this video is the same as the "hyperkalemia" video. If you have watched our hyperkalemia video, you may want to skip to 1:19. If you haven't, here is the hyperkalemia video : ua-cam.com/video/-32U9eU1hdM/v-deo.html
Enjoy learning!
Alila Medical Media please make video on blood pressure
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This has happened to me twice so far... it's torture, i had gone to e.r three times in four days until someone listened to me finally.
I'm 10 years in since my first attack and I was just diagnosed officially today. They have done genetic testing, everything under the sun in the 10 years but it was an EEG test that showed decreases in neurons firing over a 1 hr period that was the smoking gun. It was a significant drop too. This disease is killing me. I have to go see a heart doctor too now since the heart is a muscle. Even though they never had an official diagnoses they were treating me for hypokalemia. I hope you are able to control it better than I am.
I just had my 1st hypokalemia attack and ended up calling an ambulance. I don’t wish this to nobody. Sending prayers to everyone who has experienced this episodes, stay strong and healthy 🙏🏽
Thank you so much!
You just answered exactly what I was wondering
Hello help . I feel unbalance everytime i stand and sit.. its because of my low potassium?? I went to doctor my postassium is 3.27
My mum died in hypokalemia lastyear sad coz doctor never told us she suffer in hypokalemia and the the time she die her death certificate is she suffer in hypokalemia..
Thanks for clear explanation.. How to simple measure in daily basis that our body is low of potasium (hypokalemia), until now sometimes the hypokalemia attack and still don't know why?
Im stoked! This is awesome! Made correlating easier. Thank u.
thank you so much for such a wonderful explanation, now it all makes sense in my head
Thankyou in only 5mins u made the understanding easy💕💕
The video is so effective for Good understanding
I have this disease,its very fair. Please make more videos like this. when I explain it to people they think im egzagerating
Me too no one not even most doctors believe me
Thank you for this!
Very nicely explained
Thanks
Thank you very much for sharing this to me because this is one of my diagnosis
You saved my day, thank you so much
Here's the feeling for you the hyperexcitability=anxiety feeling.thwn comes the lack of being able to go to sleep.and at this time if you fall asleep you get a startle with both palpitations and a slight not being able to breath and a feeling of dizzy at the same time.at this point in time I get up and take 4/99mg potassium pills.i also at this time my excitability has turned into convulsions.if I did not take the potassium then through out the night I would have palpitations and convulsions in my sleep when I awake it would start with convulsions had I still not taken any potassium I would have convulsions through out the day.had I went another day to weeks with the potassium I would convulse while walking when I get upset and it would turn into drawing up archers back.a type of awake seizure.still no potassium my face starts to pull like I'm having a stroke my legs don't want to work and I begin to drool at the mouth and draw up.oh one more early sign is hands drawing up.right now I am waiting for my potassium to take affect so I can go back to bed.potassium and magnesium need to be level.magnesium is stored in the bone marrow.zinc helps you absorb magnesium and vise versa.good night.
Thank you i just found out this is what i have& that this condition is the cause of my complications this is exactly what I've been going through. Thank you so much for posting your comment these are the symptoms dead on
Very well explained!
I am suffering from hypokalemia since 2001. I had no idea, just getting paralysed. I was rushed to hospital and my blood potassium was 1.7mmol/L. Potassium was injected with normal saline. I narrowly survived death. Since then I live in tablets and IV drips.
This was great, I have been researching "thyroid candida" for a while now, and I think this has helped. Have you ever come across - Yannabarn Vanish Thyroid - (just google it ) ? Ive heard some interesting things about it and my brother in law got cool results with it.
@@fiorenzalifonti6714 Thank you very much. I will Google it.
@@shahinrezakhan That person is not real, and they are referring you to a scam....
They wouldn't push potassium IV. Potassium is always an IV drip. Never pushed through a saline lock because it is so dangerous, regardless of your potassium level.
How are you not ingesting enough potassium from food?
Is it possible that some people would need to remain higher than the minimum? I was at 3.5 & had full body muscle weakness, confusion, and cramping throughout whole body including internal organs! Hypokalemia also increased CO2 so that was high and it was like lungs didn’t want to expand all the way. It was super weird and no fun! I doubt I’d survive if I dropped any further😓
Can you add a video like this on hyper and hyponatremia
Thank you so much for making the videos . I have a question .Why would increased gradient cause hyperpolarization? I thought less K+ on ECF side means....less +ve charge in ECF....
That means the ICF has relatively more +ve charge .....less negative potential.....
I dont know if that is the cause for increased excitability...
I see your point, but it is a dynamic process. The increased gradient of K+ will increase the driving force for K+ to move out of the cell. It will drive more potassium from inside the cell than usual, so the inside will ultimately lose positive charge.
Fascinating! Thank you for this video :)
fantastic explanation of the HypoK and ECG changes - Ta
Wow,greatly and easily explained....thank you so much
Great video....it covered everything
Very useful.. thanks a lot
Thank you so much! God bless you
Thank you very much. Could you please provide video about the early after depolarization (EAD) and delay after depolarization (DAD) and what the change of the ECG during that change of the action potential? (if possible). Thank you again.
i Think there is something wrong, I read on physiology books that the intracellular value of the resting potential is NEGATIVE compared to the external one (and by this derives the basal value of -70 for most cells, meaning that the INTERNAL CHARGES are more negative than the external ones). If, as shown in the video, you subtract positive charges from the outside of the cell, keeping the intracellular charges as they are, the difference in potential should go to a depolarization and not to a hyperpolarized one (if you subtract positive charges externally the inside becomes relatively more posive than the before, but the basal situation is still that you have more negative values in the inside, so those basal negative values should actually become "more positive").
Could you explain this event please?
Yes, i believe they meant that K levels decrease in the intracellular space instead of the extracellular space. This is the only way the cell would be hyperpolarized becoming more negative in relation to the exterior. however this is not the only video I have found saying this so I'm not sure.
This is the first thing I thought too! It doesn't seam to add up.
I had the same doubt, but the memb. potential is actually determined by ion movement. Let's take k+, as it affects RMP most.
If k+ is more on inside (normally), there is a concentration gradient which directs outside, i.e. k+ try to move outside. By diffusion k+ moves outside; now we also have negetive charge proteins inside that can't move out. This makes the inside more negetive compared to outside.
As more k+ move out by diffusion conc gradient falls but the electrical gradient develops that pulls k+ in. At a certain point the two opposing gradients are equal and the ion stops moving[the electrical potential now is called nerst potential].
So if k+ level increase outside cell, the conc gradient across membrane for that ion falls, so diffusion outside is less-->electrical gradient not developed much and the inside is less negetive. And the membrane potential is lesser.
If you want more detail may check Diffusion potential, nerst potential, Goldman-Hodgkin-katz equation. It's quite well written in Guyton and Hall textbook of Medical physiology
@@preetamdandapath5277 but K levels decrease outside, not increase. you explained what happens if K is more outside
@@poptudor5286 I mean the potassium level is still more in the inside, but the difference between inside and outside concentration is reduced (lesser gradient).
In hyperkalemia, the k+ level outside is still less than inside, but it's more than the normal level of k+ that should be outside.
Just a hypothetical example-
K+ level-
Initially:
Inside =150
Outside=10
Later:
Inside=150
Outside=30
This is hyperkalemia. Now less conc gradient of k+ causes less diffusion of k+ outside and membrane potential becomes more positive ( because the negetive proteins that were causing membrane potential to become negetive are kept neutralised by the k+ inside.).
Similarly if K+ outside decrease (in hypokalemia) the concentration gradient increases and more k+ diffuse out; this creates negetivity inside (as negetive proteins remains inside) and membrane potential becomes more negative (hyperpolarisation).
Hope it clears your doubt.
Fantastic
Thank you!
I have a question about how can inward current exceed the outward with a low concentration of k iyons in the ecf?
Its my question too.
One reason is that: outward canals are blocked, by intracellular cations like Mg.
Take a look at this review, from aha journal :
Electrophysiology of Hypokalemia and Hyperkalemia
(Aha journals)
This was a great help. Thanks you. I had my pituitary gland removed, when it was inflamed, am=nd mistaken for a tumor. Learning online without a family dr. so asking if you can make a video on how hydrocortizone takers, with no adrenals, are affected by caffeine?? Tnx
Thank you very much
Nice and helpful video, as always, thank you🙏
How oedema occurs in reduced blood flow,please make a video for it
Hipo/hypernatremia next please!
thnks a lot...........this has really helped me
well explained! thank you
Excellent!!!!!!
OMG AWESOME!
Amazing video
❤️ Thank you so much
Please address premature beats: PAC and PVC
Thanks
thanks for the good video!
My fav channel learned a lot thanx ❤️❤️❤️
I liked it very much sir
A kind request to send me all such
Medical information sir
The video was great, where did you get the information about a paradoxical decrease in efflux of potassium during states of hypokalemia? It makes sense, and is the answer I was looking for which is why I'm wary to accept it
Hypokalemia speeds rapid inactivation of IKr [10] and slows reactivation kinetics of Ito [11], reducing outward repolarizing current even with moderate hypokalemia [12]. Hypokalemia also downregulates IKr expression within hours [14]. Thus, despite increasing the driving force for K+ efflux, hypokalemia reduces the number of conducting K+ channels during repolarization. His-Purkinje fibers are particularly susceptible to EADs, DADs and automaticity because of their lower resting K+ conductance (less IK1) compared to ventricular myocardium [15].
www.ncbi.nlm.nih.gov/pmc/articles/PMC5399982/
How magnesium impacts body ??
in the video you stated the hypo-tension is a symptom but quoting from medscape it says that hypokalemia causes hypertension.
"Low potassium intake has been implicated as a risk factor for the development of hypertension and/or hypertensive end-organ damage. Hypokalemia leads to altered vascular reactivity, likely from the effects of potassium depletion on the expression of adrenergic receptors, angiotensin receptors, and mediators of vascular relaxation. The result is enhanced vasoconstriction and impaired relaxation, which may play a role in the development of diverse clinical sequelae, such as ischemic central nervous system events or rhabdomyolysis.
Looks like the quote is about long-term effect of CHRONIC hypokalaemia. In the video it's about ACUTE hypokalemia symptoms, although it should be noted that they are not very specific, for both hypo- and hyper- K+
okay got that . but what explains hypo-tension ,i mean how does it occur in hypokalemia?
I would think a sharp decrease in any electrolyte would at least temporarily decrease blood pressure as it affects solute/water balance? In reality things may get more complicated than that and we cant explain everything in medicine, far from that, unfortunately
that's right .thanks a lot .great videos by the way (Y)
Thank you!
you are the best
Thank you sir for this good video.but I have a question:how can hypokalemia cause hydropic degeneration?
always AMAZING
Thank you!
Tq u
Simply gorgeous
why are you talking about a pacemaker action potential and using a cardia myocyte AP to explain the effect. thats so confusing
Provide muscle mechanics video (tension length graphs)plz
Thank you for the explanation, th best I've seen so far. I would just stress the fact that hyperpolarization of the membrane only occurs in mild hypokalemia.
Pedro Santarém Neves why
are you ok n0w
Tq
Im not sure If I get it right. In the conductive cells of the hearth less K in ECF cause K moving outside cell and thats the motor for faster Na ions move into the cell by funny channels resulting more frequent action potetnial ?
2:34 I didn't get it, less potassium outside the cell would make the cell less negative which means depolarised !! Not hyperpolarised
How about symptoms? Not what good it does! Like any headaches?
Let's save some lives
Can u please explain what u mean by the funny current enhaces due to excitability?
Sir I am Facing Hypocalimia patent what is the best solution
Spelling 😂
take a blood test are you ok n0w
Me also are you ok now
Watched this in 2024
Anyone can answer my question. I feel unbalance everytime i stand or sitting.. i have 3.27 postassium .. is this because of my low pottasium?? Ive been paranoid that i might brain problem..
Ask your Dr. But potassium has to do with the heart from my understanding
Discuss about a abg
🙏👍👌👌👌👌👌 Thank you
how is hyperpolarisation making Purkinjee conduct faster since theres no funny sodium current in PJ cells ryt?
Funny currents are present in all cardiac pacemaker cells, Purkinje included: www.ahajournals.org/doi/full/10.1161/CIRCRESAHA.109.208041
Guys english is my native tongue,can somebody explaine to me What she really tellling from 2:18 onwards. “ across the cell membraine” is it inside the cell or outside? Thansk in advance guys
*not my native tongue
It's not "inside" nor "outside". Here it means the difference "between" the 2 sides.
Purkinje fibers have funny current? This is news to me
Mam, funny channels are present only on sa node
Funny currents are present in all cardiac pacemaker cells, Purkinje included: www.ahajournals.org/doi/full/10.1161/CIRCRESAHA.109.208041
Kindly slow down the rate of reading words, it becomes difficult with that speed and accent for few students..otherwise content is unmatcheable with others.👌
There’s literally a speed button on UA-cam.......
Hindi m bnao ....pls
Coconout and banana yess
my mum die lastmonth of dis hypokalemia;(((
My condolences, I hope you and your family are doing fine
RMP: **being more negative**
Purkinje fiber: I should increase my K conductance in case nonpacemakers could not have enough current to make an AP
SA node: makes sense
3:18
Purkinje: Yeeeeaaah let's ride
SA: I don't think that's how heartbeat works
Purkinje: fiRe At WilL
SA: Someone please-
Mashallah
I want translation to Arabic with all videos please
hypokalemia causes hypertension, right ?!
No, hypernatremia does.
Hopp causes flaccid muscle tone, weakness, risk of fall during waking up from bed.
💜🧡❤️💛💚💙
Paralytic illius
How many carnivores in the comment section?
Hypertension should be seen with hypokalemia
Dic,
Blood pressure medications can they increase output of potassium & cause heart ❤️ pain/ irritability??
im experiencing this
@@asante6010 sorry to hear it. Hope you have or get good care.