...since when was this considered a myth?? The heart is positioned asymmetrically, with only about a third of it being actually behind the sternum. Two thirds are on the left side.
Yeah, no.
Web MD: https://www.webmd.com/heart/picture-of-the-heart
"The heart is a muscular organ about the size of a fist, located just behind and slightly left of the breastbone. The heart pumps blood through the network of arteries and veins called the cardiovascular system."
University of Michigan: https://healthblog.uofmhealth.org/heart-health/anatomy-of-a-human-heart
"Located between the lungs in the middle of the chest, the heart pumps blood through the network of arteries and veins known as the cardiovascular system. It pushes blood to the body’s organs, tissues and cells. "
Quora answer from a cardiologist: https://www.quora.com/If-our-heart-is-in-the-middle-why-do-we-feel-the-heartbeat-on-the-left
"The question is correct that most of the heart lies in the center of the chest. Only a variable sized portion protrudes to the left.
So if most of the heart is in the center, then why isn’t the hearbeat felt in the center of the chest?
There are two reason you don’t (typically) feel a heart beat in the center of the chest:
The sternum is a thick bony structure that decreases the transmission of force of the heart beating. (There actually is vibration there - it is just too small typically to feel. You can hear the vibrations with a stethoscope however.)
The Right Ventricle pumps less blood. The Right Ventricle is under the sternum and (typically) in the center of the chest beats less vigorously than the Left Ventricle because it is only pumping blood through the lungs as opposed to the entire body.
The reason you feel the heart beat to the left is that a portion of the left ventricle lies against the skin between the rib cage on the left side - and effectively “bounces” contraction waves against that soft area. The result is a “PMI” - point of maximal impulse where the heart beat can most be felt. As the heart enlarges, the PMI moves further and further laterally, away from the center. The PMI can sometimes be used to diagnose abnormal heart enlargement."
Youtube video explainer: https://www.youtube.com/watch?v=idkPch61aMw
Which is pretty much the same thing. The heart is asymmetric, not directly in the center of the body, with more of it on the left and the left ventricle does more of the "hard work" than the right. In a person with mirrored organs, this would be reversed, with what would normally be the "left" ventricle being on the right side of the chest instead of the left and, thus, the heartbeat would be felt over the right side.
As for how the classmates would find out, others have mentioned that they have physical exams in Japanese schools and I'm sure those include the standard things like using a stethoscope to listen to your breathing and heartbeat. When the nurse puts the stethoscope to her left side and hears nothing, then looks confused, the girl would have to explain that she had the condition. Or it would be in her information and the nurse would put the stethoscope on her right side and the kids around her who are smart enough to notice the difference might point it out.
However, the more likely explanation is that she was self-conscious about her condition and had low self-esteem because she 'always hated her own body'. This could be an analogy, of sorts, to body dysphoria with trans individuals... maybe... People with low self-esteem who isolate themselves are frequently the people who are targeted by bullies because bullies don't go after hard targets. They aim for 'low hanging fruit', so to speak. So there's no guarantee that the people bullying her had any idea about her medical condition. Just that she was a loner that kept to herself.
(Not that being a loner who kept to herself and then started dating the new girl who was a lesbian was going to change anything about the bullying other than giving her someone who would be a buffer between her and the bullies and might not put up with their crap.)
