When Alma, Robin and Lisa's child gets sick with Viral TB(which is a virus I made to prove that these humanoids have a much stronger immune system than us), it starts off like the flu. She gets a sore throat minutes after breathing in the virus. She then gets nasal congestion, tonsillitis, cough, and hours later, pneumonia. Some of what she coughs up infects her digestive tract. First her esophagus gets inflamed making it hard for her to swallow. Then her stomach gets upset and she gets nausea and vomiting. Her small intestine then is not able to absorb as well as it should so she gets diarrhea and malabsorption. Then she gets appendicitis and soon after, colitis which causes her diarrhea to be painful. Later on she gets rectal inflammation also known as proctitis. Last but not least her liver enlarges. This is bad enough as it is but it gets worse. Some time later(1-2 weeks) the virus enters the bloodstream of one of her circulatory systems. But it doesn't cause vasculitis until much later(months later). Instead it floats to her heart causing chest pain, hypertrophy, and cardiomegaly. So one of her hearts gets bigger. This can cause her to be short of breath. If it weren't for granuloma formation in this illness, she would die when her heart got infected from fluid loss due to pneumonia and diarrhea. Anyway, I know that this means that she has a higher chance of getting a heart attack. However the fact that she has secondary coronary arteries from the opposite aorta supplying the infected heart with oxygen means it is much lower than it would be in a human with the same heart condition. But I'm wondering what the actual chance of getting a heart attack with symmetric ventricular hypertrophy, chest pain, and cardiomegaly is. I imagine it would be low but how low? Low enough not to worry about MI at her young age? I tried cardiology forums and they said "this heart attack thread isn't relevant, locking" so my steering clear of medical forums was right. They won't help at all with this heart attack scenario. Alma is 17 just to give you an idea of how young she is. Anyway, not only am I wondering what the chance of a heart attack in this scenario is but I am also wondering how to approach this heart attack if it happens. I was thinking maybe this: This is just an example of what I might do at this point. Do you have any suggestions about what I should do if my story gets into this adolescent heart attack scenario?
This 'viral TB' and your humanoids having two hearts puts this so far out of the realm of real physiology that a) I think you can just make up whatever you like, b) I doubt that you need to explain the pathological nitty-gritty in so much depth, and c) I'm not surprised the cardiology forum didn't entertain you, and I similarly have little idea what to advise on the technical front. But I'll have a stab... What are you imagining is the cause of the infarction? What is blocking the coronary arteries to cause ischaemic damage? Some kind of granulomatous embolus? If so, I'm not sure what medical intervention would be possible; a standard thrombolytic will be useless, and granulomata are notoriously hard to clear or get drugs to penetrate. Otherwise... I suppose she could have some kind of hypoxic heart attack relating to congestive heart failure (which I think is much more of a concern than myocardial infarction), but it would probably be right in the terminal stages (the straw that breaks the camel's back, perhaps) and I doubt she'd be conscious for it (her brain would probably be deprived of oxygen before her heart). I'm actually surprised she's survived 1-2 weeks of all the other business to get into heart problems, unless there's a lot you haven't mentioned, and I really doubt she'd have 'seemed fine a few days ago'. If the point is to show that the humanoids' immune system is better than ours, I assume you don't want her to die, and I'm not really sure how having her severely affected like this is making that point... There's a lot that could be discussed but it would take forever, and basically I think you've made this a lot more complicated for yourself than it needs to be. You've come up with a lot of realistic(ish) detail for a complex topic - that's very impressive for someone who (if I'm not mistaken) is quite young - but I think you might be trying to run before you can walk, so my main advice would be to simplify and skirt around the detail.
I think the cause of the infarction would be the carditis that results(Simplified to carditis since all layers are affected). If the heart gets inflamed(regardless of layer or localization) it is under more stress. The more stress the heart is under, the more likely that a clot from somewhere else would break off and the more likely a clot would form in the primary coronary arteries. The second heart would compensate by putting itself under stress to try to prevent the heart muscle in the infected heart from dying. Eventually that cardiac stress wouldn't be enough and that is when the MI would likely start. I would imagine that this would be very similar to the MI in this video: That is that it is very painful and it is obvious that something is wrong while she is still conscious(The fact that her species has 2 hearts and circulatory systems would further promote consciousness during MIs) And the way I made their immune systems, this infection that spreads from 1 organ to another is long lasting but temporary. The reason? When the infection is latent(or in other words inactive), the memory T cells and memory B cells have time to divide and patrol the area. Thus each bout of Viral TB lasts for a shorter amount of time before granuloma formation and overall, there are less and less viruses per cycle until eventually there is no more virus. But in Alma's case, the virus doesn't cause vasculitis(Inflammation of blood vessels which itself, even without atherosclerosis, can raise the chance of an MI) before it causes carditis. And yes, to someone with a not as strong immune system it would be surprising that someone could survive 1-2 weeks of severe digestive issues and viral pneumonia but here again I made them better than us in built in defenses(like a food storage organ connected to the stomach as not only food storage but as an antinausea measure as well so that if she throws up, she is only throwing up acid and bile and any nutrients in whatever she drank, not food that she has swallowed and started to digest. So this helps with dehydration and malnutrition to make it less severe, especially that from diarrhea). And the "feeling fine a few days ago" is like "besides chest pain, everything is fine" as to how well she feels because when her Cardiac viral TB starts, her respiratory and digestive infections from the same virus are latent(or inactive). And simplifying is hard for me, especially on the biology side of things. Usually the biology is too complicated for most people but the general story is too simple. I try to find this balance by expressing the complex biology in a more understandable way so that I still get the complexity but more people will understand it.
As I said, this is so far out of the realm of real biology that you can imagine whatever you like to bridge a gap in plausibility, as you're doing People can't give you feedback on how likely something would be for creations of your own imagination. If you're aiming for a thrombotic myocardial infarction (note: MI can also stand for mitral insufficiency, another cardiac disorder), you may want to reconsider the hepatomegaly you've given her. If she's got liver pathology, her production of clotting factors might be dampened, so thrombi may be less likely (although she could still have platelet plugs without secondary coagulation I suppose). I also think thrombosis from endocarditis/vasculitis is more likely to be micro-, occuring in capillary beds (brain, eyes, kidneys, etc); you'd need a pretty big thrombus to occlude a coronary artery, which has a relatively large lumen diameter. Regarding making a point of her having a stronger immune system: if she's having 'severe' clinical signs, that suggests that her immune system isn't holding up too well. Maybe it's just an incredibly nasty disease and her immune system is actually doing pretty well considering, but you'd need to show how feebly a standard human would deal with it to get the point across. I'm not sure who your intended target audience is for this, and if you're just writing it as a biology learning exercise for yourself that's fine. I think most people are going to want to read for the story than the biology detail though, so I stand by my recommendation to gloss over it and focus on the plot and characters. Without wanting to speak for others, I suspect you'd have had more respondents to this thread if it wasn't such a pathology swamp. It might not even be a lack of understanding that turns people off so much as a lack of interest. Your characters emotions and implications for the overall plot will interest most people much more than biological detail. It's also far easier to have plausible biology without as much detail: the more you zoom in, the easier it is to see the holes.
