NEED HELP RIGHT NOW FROM MED STUDENT

I'm not a medstudent, and probably couldn't answer that much, but i did have a human phys class.

Why would lactic acid cause CHRONIC pain/fatigue. lactic acid aches are only temporary, so i don't think they can explain.

blockage of some artery??? these are random gueses, i really don't know, but maybe you can consider it and see if would apply. proteins take more energy/time to metabolize.. i think.

just a few ideas. i don't really remember that much from phys class. but, lactic acid pain is only temporary.

hope this could help... a bit.
Sonya

 

coronary artery occulsion?

 

The chronic pain can be caused by muscle damage due to the lactic acid build up or breakdown of muscle.

 

here is my 2-cents,
I believe abs1 is correct; it is coronary artery occlusion. atherosclerotic plaque builds up in coronary arter (CA) (though it is highly unlikely to build up enough plaque to occlude an CA in a teenager) and decreases blood supply to heart. That is normally not a problem because CA has a very large reserve; however, it becomes problematic under intense excercise due to increase need for oxygen supply for heart. This will account for her fatique,gasping and panting for air because her heart is not receiving enough oxygen. Her chonic pain of her shoulders and arms after training is probably due to latic acid accumalation. Finally, her severe pain in the left pectoral region is also due to lack of blood supply to her heart from atherosclerosis or something else under intense exercise that cause ischemia of heart.

hope this explanation will help
gui-gui
MS-2

 

While I agree that the problem does seem to be cardiac, I think that atherosclerotic disease in a young girl is a bit unlikely. More often when young people have cardiac problems, they are due to congenital cardiomyopathies. This seems like it might be a case of Hypertrophic Cardiomyopathy, which is due to a genetic defect in the cardiac myosin beta heavy chain. The defect causes the cardiac myocytes to greatly increase in size and number, leading to thickening of the ventricular walls and septum. This causes a reduction in cardiac output, which when coupled with the increased oxygen demand of the hypertrophied heart, leads to ischemia and chest pain. Also, the decreased cardiac output (aggravated by exercise) would reduce the amount of oxygenated blood reaching her muscles, leading to anaerobic fermintation producing lactic acid.

Incidentally, in case you can't tell, we just finished a block on cardiac disease!

Mango MS2

 

I'm with Mango on this one: it's her heart. Why would lactic acid buildup be specifically localized to her left pectoral region? And why wouldn't her teammates be experiencing similar problems, since they're all working at similar levels of activity?

As Mango pointed out, there are causes other than atherosclerotic plaques that would cause ischemia/caridac insufficiency, most of them congenital (i.e. not age-related). Alternatively, she does have coronary artery disease due to familial hypercholesterolemia -- people with this disorder develop extremely high circulating cholesterol levels and can get heart disease at a very young age. In either case, the reason that the problem hadn't surfaced before is that her cardiac function was probably sufficient for everday levels of activity, but couldn't handle the increased demand of athletic training.

By the way, her coach suggested she eat more carbohydrates so that she'd have an instantly available source of energy, and build up her glycogen reserves as well. However, if the problem is that her heart is unable to deliver sufficient oxygen to her muscles (including the heart itself!), then all the carbos in the world won't help.

Here's a website about <a href="http://www.cardiomyopathy.org/html/which_card_hcm.htm" target="_blank">hypertrophic cardiomyopathy. </a> Symptoms definitely match.

 

Worst case scenario- Mango's right. Hypertrophic cardiomyopathy is one of the leading causes of sudden death in young athletes. Get her an echocardiogram before returning to strenuous workouts - seriously. Her symptoms may be caused from something benign, but you don't want to miss a potentially dangerous, and life-threatening medical condition. Not trying to scare you, but get it checked out just to be safe.

 

Oops! sorry, thought this was a friend of yours! i should've read the original text more carefully! Good luck in physio!

 

If I understand correctly, this question is getting at the difference between fast and slow twitch muscle fibers. Fast twitch fibers are the easily fatigable fibers that burn glucose anaerobically, building up muscle lactate concentrations. Slow twitch fibers are "endurance" muscle, with lost of mitochondria; these fibers use aerobic metabolism.

So if the swimmer switched from a protein/ fat loaded diet to a protein loaded diet, she probably increased the load on her easily fatigable fast twitch fibers. The cramp is due to lactic acid buildup in the pectoral muscles, which she is exerting during swimming.

I don't know if this is the right answer, but I really don;t think these are cardiac symptoms.

 

The carbohydrates are to build up her glycogen stores in between training, so that her muscles have adequate amounts of oxidation to creat energy.

I personally feel you guys are reading way too deeply into this. She is young and she is out of shape. I don't she has all of these cardia maladies.

She could very well be acidotic.

 

i'm not a med student, but a swimmer.
and i mostly agree with pdx. this is one of those textbook questions eh? you're probably looking for some heart related answer, but it's not realistic.
if she's on a swim team, she must be healthy (swimming miles every day before acquiring the problem..). perhaps she stopped swimming for a few weeks, so that explains all those problems, but they should all go away after a few days of training.
the diet doesn't make that much difference, as long as you don't use steroids/supplements. and also during the season i have about 5% fat (look anorexic) but i really eat a lot of everything. but obvioulsy a lot of fruits & vegies & meat.

and the worst problem that a swimmer may have is a stagnation of progress. but a swimmer developing a heart problem is just a lie.

 

Well, maybe.

Since the symptoms are so vague, they could really apply to a number of maladies. Perhaps the best thing to do is to take your cue from the area of physiology that you're currently studying: if you're immersed in metabolism, then yes, the answer may well be deconditioning/lactic acidosis, etc. But if you're in the thick of cardiovascular physiology, cardiomyopathy is more likely.

But pj, please don't be so quick to argue that an athlete can't have heart problems. Someone at my high school -- young, athletic, fully conditioned -- dropped dead of a heart attack mid-game. It happens

 

Atherosclerosis!?! Come on guys... unless this patient 1) has a congenital disorder or 2) has undergone a transplant, this scenario is unlikely.

Hypertrophic cardiomyopathy is a good idea. What's her blood pressure though? Does she have a murmur?

How about this...

She's young, female, with increasing fatigue with exertion... how about autoimmune problems?? Myasthenia gravis should definitely be ruled out in this patient. Autoimmune myocarditis (usually a/w Coxsackie B3) must also be suspected. How about vasculitis?

Since we don't know about dyspnea or potential oral contraceptive use, I'm not a fan of pulmonary embolisms or other coagulopathies. This seems like a sub-acute/chronic condition.

My differential...
1. Autoimmune disorder (Myasthenia, autoimmune myocarditis)
2. Vasculitis (e.g. Takeyasu's dz)
3. Cardiomyopathy

What do y'all think??

--doepug
MS II, Johns Hopkins

 

Good call doepug, Takayasu's is a real possibility. That would explain the symptoms (claudication) being limited to her upper body. I'd like to know how her upper extremity pulses compair to the lower. Is she lightheaded?

Autoimmune is also an interesting idea. What about rheumatic heart damage from childhood? Or even a congenital malformation like an atrial septal defect causing a left to right shunt that never bothered her before she began atheletics?

This case is way too vague, we need more info to really narrow it down.

 

Its normal fatigue and a PULLED MUSCLE. You can tell everyone who answered this question is a pre-clinical med student because everyone was looking for the damn unicorn when they heard the hooves. Think simple before you do a $5000 cardiac workup. I think this post was up in another forum and I gave my opinion there as well.

 

I am only an MS2, but my 1st thought was exercise induced asthma with muscle fatigue/soreness associated with a new training program. The chest pain could be soreness of accessory muscles of respiration.

 

For her young age, congenital heart diseases are likely. Metabolic disease such as McArdle's disease is a possibility too--although I don't know if McArdle's dz has anything to do with physiology.

McArdle's dz is a type V glycogen storage disease (think Biochem in medschool). There is an increasae in glycogen in muscle but cannot break it down (deficiency in skeletal muscle glycogen phosphorylase), leading to painful cramps, myoglobinuria with strenuous exercise.
When exercising either low load, prolonged time, or rapid bursts of exertion can result in severe cramp and/or pain. Progressive weakness in muscle may occur later in life. Often the disease is not detected until the twenties or thirties as the disease is less severe in children.

Pei

 

All right, I've gotta step in here. Please keep in mind that there is a HUGE difference between "possible" and "likely". Congenital heart disease, while possible, is certainly not likely. Yes, it happens, and it's good to think about it, but remember that there are several MUCH more common causes of this complaint, by far the most likely is plain old being out of shape and not eating enough protein (they gave you the hint right in the question!).

Preclinical medical education tends to stress the zebras much more than the horses, because the zebras are often much more difficult to learn. The good thing about learning about the zebras is that once in a while a patient comes along that has one of those rare diseases, and you won't recognize it unless you know that that disease exists. However, what then becomes difficult to learn when you start out in clinics is that uncommon presentations of common diseases happen MUCH more frequently than common presentations of uncommon or rare diseases.

Now I'm assuming the original poster is taking an undergraduate physiology class, which means that the class probably doesn't stress the obscure metabolic diseases that a med school physiology class would, since I think that would be way above their level. Therefore, I'm going to agree with Fah-Q and say that this poor girl has a pulled muscle from being out of shape and not eating enough protein. My recommendation -- continue to be active and do some workouts during the off-season to avoid being so out of shape, and eat plenty of meats and vegetables during the on-season to make up for the muscle she destroys.

PS -- I would only truly consider exercise-induced asthma if she was already in shape, and feeling out of breath during her normal-intensity workouts. (Note that she is in her early stages of training, and she is going through a new exercise routine). Now if her shortness of breath continues once she is more in shape and the shortness of breath has no real relation to the level of intensity of her workout, then I would consider asthma as a possibility.

Sorry for my little diatribe.

 

Fah-Q and AJM, I agree with the spirit of your posts: it's certainly better to look for the garden-variety explanation of symptoms rather than the exotic one IN REAL LIFE. But we're not dealing with reality here, we're dealing with a rigged case that's part of a physiology course.

I agree that some of the arcane diagnoses that have been suggested are probably not what the question is getting at. And we're likely not talking about a cardiac problem at all, since AntGod's class is currently studying metabolism, not cardiovascular physiology.

But I think that the lactic acid/pulled muscle explanation is TOO simple -- it just doesn't have the proper didactic case-study feel to it. Therefore I'm adding my voice to those who have suggested a glycogen storage disorder. Pompe's disease is characterized by exercise intolerance and painful muscle cramps (!), but even more importantly it's an easy-to-research condition (i.e., not TOO obscure) that affects metabolism -- a perfect fit for AntGod's class.

And hey, AntGod: do be sure to let us know what the correct answer actually is!

<img border="0" title="" alt="[Wink]" src="wink.gif" /> <img border="0" title="" alt="[Wink]" src="wink.gif" />

 

Hey, they may be zebras, but its fun to stretch your mental muscles a bit every once and awhile! Besides, congenital heart problems would be on any complete differential of a young person with exercise induced symptoms (along with asthma, and other more common problems). Yes I am a preclinical student, but we write problem lists/differentials all the time in our Intro to Clinical Practice course. So it's not completely foreign to me.

Anyhow, it was a college phys class problem, so that clearly rules out most of the rare disorders we've been discussing. But it was fun anyway...

 

Since the original poster was studying metabolism in his human physiology class, my answer would be McArdle's disease (not Pompe's, McArdle's is the one with excercise intolerance).
A rare glycogen storage disease would make this a good case study for his class.
The student who posted this case has already turned in his answer--with the most likely answer if in real life: poor stamina, lactic acid build-up and muscular strain. This can be the correct answer too, but it would make this a boring case study.
Anyway, it was all for fun.

<img border="0" alt="[Clappy]" title="" src="graemlins/clappy.gif" /> Pei

 

While I agree that it's good to flex your mental muscles, what disturbed me was that it seemed like there was lots of muscle being flexed without anyone (save a couple of people) mentioning or giving thought to the common things. Yes, you do come up with a differential diagnosis, but the top of your list should typically be the most common diseases. That's why I was blaming preclinical medical education -- they train you to mainly consider the rare diseases without giving so much as a wink to the common things. And the funny thing is, common disorders can be interesting too! For example, I would not be at all surprised if the professor wanted to bring up teaching points on the effects of diet (particularly protein vs. carbohydrate metabolism) on energy production, and specifically on lactic acidosis and muscle breakdown. There are several metabolic pathways that you need to understand just to know those "simple" concepts, and that would be something I would expect an undergraduate (or even med school) physiology professor to teach.

So sure, it might be a boring case study for med students who would rather be discussing something like methemoglobinemia or Wilson's disease, but for an undergrad it may very well be a useful teaching exercise.

Now watch, it'll probably be a case of McArdle's.

And keep up the mental flexing -- as I said before, in the future if you do happen to see a patient with one of these rare diseases, you won't be able to recognize it unless you think about it as a possibility. <img border="0" title="" alt="[Wink]" src="wink.gif" />

 

Peiyung:

From what I've read, you can get muscle cramps and exercise intolerance in adult-onset Pompe's, but you're right: those symptoms are really the hallmark of McArdle's. Never could keep them straight!

Yes, it has been fun. Super fun. Let your geek flags fly, everyone!

<img src="http://www.theunholytrinity.org/cracks_smileys/otn/blobs/boldblue.gif" alt="" />
<img src="http://www.freakygamers.com/smilies/s2/otn/blobs/multi.gif" alt="" />
<img src="http://www.theunholytrinity.org/cracks_smileys/otn/blobs/boldlblue.gif" alt="" />