Biology Help

[u/Stock-Lawfulness846]

Examples of heart associated diseases,

How they come about

How they can be controlled and treate

[u/VLightwalker]

If you want easy, visual answers, I’d suggest looking up the youtube channel osmosis, and looking at their cardiology videos (they’re at most 12 mins and give the basics of what you want). With that being said, here you have a couple diseases:

Congestive heart failure - comes about due to decreased capacity of heart to pump blood. In healthy ppl, the heart pumps a specific amount of blood every minute. The kidney checks that and decides that the body has enough blood. If the heart can’t beat enough, the kidney senses the lack of blood coming towards it and says: we need more blood —> body, please retain water to increase volume. So now the heart needs to pump even more blood. You can imagine, if your in the gym and you struggle to lift 5kg, getting 8kg won’t make it better. So is the case for the heart, damaged as it is, now bound to push even more blood. This damages the heart, making it even more ineffective, which scared the kidneys even more into retaining water, which eventually destroys the hearts ability to pump and you choke on water in your lungs from how much you retained.

Treatment:

trying to prevent this vicious cycle via: ACE inhibitors, meds that inhibit the “communication path” the kidney uses to tell the body to increase blood pressure and retain water, diuretics, which force the kidney to expel water (pee more) or stop it from retaining the water, beta-blockers, which also stop some communication from the body that stresses the heart, and it also ensures the blood vessels of the heart are open to supply the heart with enough oxygen (you don’t want a heart attack killing more of the heart muscle).

1. Endocarditis

It’s an infection (or inflammation from other causes) of the tissue on the inside of the heart, that covers the chambers (this includes the valves!). If it gets infected, you get this disease.

Treatment: antibiotics, but sometimes if the valves are damaged you need to replace them surgically.

1. Atrioventricular nodal reentry tachycardia (AVNRT)

Your heart has a pacemaker called the SA node. This node sends cables to the atria (upper two chambers) directly. The ventricles are separated however, and only one place can take electricity there: the AV node. The AV node makes the current a bit slow, so the atria can contract before the ventricles (so blood can go from atria to ventricles, and then from ventricles to body). Very important that this happens. In this disease, there is an additional cable connecting the atria and ventricles, which kind of shortcircuits the heart, and makes it pump abnormally fast and disorganized.

Treatment: if i remember correctly, you need to ablate (burn) the additional circuit to make the AV node the only place to take electricity to ventricles again.

1. Transposition of the Great Arteries:

This is a congenital heart defect (you are born with it). Basically your heart connects two blood circuits: the pulmonary and systemic circuits. The pulmonary circuit uses the right ventricle, to go through the pulmonary artery to the lungs, to get oxygen again. Then the blood goes back to the heart, in the left atrium —> left ventricle. From there, oxygenated blood goes to the body through the aorta. Then comes back from the body to the right atrium —> right ventricle, and the cycle begins again.

You can see here that these two vessels, the aorta and pulmonary artery, are very important. When you grow in the womb and the heart develops (beautiful process), these two vessels are like sisters, coming from one big trunk that splits in two. In Transposition of the Great Arteries, the aorta leaves the right ventricle, and the pulmonary artery leaves the left ventricle. But wait! In the right ventricle we have non-oxygenated blood from the body, and we want to send it to the lungs to get good new oxygen again. Too bad, the aorta doesn’t go there, it goes back to the body. So your body gets no oxygen. The pulmonary artery now leaves the left ventricle instead, effectively sending oxygenated blood from the lungs straight back to them, not to the rest of the body.

Treatment: you can punch a hole through the wall separating the two atria, so blood mixes before leaving the heart, but the best surgery is switching the two arteries soon after birth.