What Happens to Your Body When You Get a Heart Transplant

So, how does a surgeon even get to your heart in the first place? The answer isn't pretty. After the initial incision in your chest, a surgeon has to get past your ribs. They do this by separating your breastbone, pulling open your ribs, and, in some cases, even setting parts of it aside in order to get in. That's right, they'll actually be breaking your bones to reach your heart. This may seem drastic, but because of the precision and time constraints involved with this procedure, it's simply the best, most efficient way to get everything done. Don't worry, though, they'll put you back together with surgical staples. 

In order to get a heart transplant, you need a second heart, so where does that come from? Unlike with other transplants, you can't exactly get a heart from a live donor, so you'll get it from someone dead... sort of. You see, the human heart can't really survive outside the body for very long. There are machines being created to keep hearts alive outside the body, but as of now we need a living human body to keep the heart alive. Surgeons look for a heart that matches your blood type and would work well in your system, but they also look for a heart that is still beating inside someone who is brain dead.

Because they are brain dead, they are basically no longer living, but their heart can still be kept beating and alive. As you go under for surgery, the heart will be harvested from your brain-dead donor, then transported to you as fast as possible. If the heart remains in transit too long, say over six hours, it can become useless, so surgeons prefer to do a transplant in the same location as the donor. 

When your heart is removed, it's not like you can keep living very long. So what pumps your blood after your heart has been taken out of your chest during surgery? What keeps your body functioning? For a little while, this is all done by a machine. A cardiopulmonary bypass machine has the ability to process your blood and breathing, circulating oxygenated blood back into your body as an artificial heart. It cannot do this forever, of course, but it works long enough to get you a new heart.

Once a surgeon gets to your heart, they use a series of tubes to attach to the most major arteries. They then switch your blood over to the machine, and it takes over. With that attached, the surgeons are finally free to remove your old heart and can begin the process of putting in the new one.

When the fresh heart is finally put into place, surgeons have to make sure that it doesn't move. You might think that just means attaching it to the arteries one by one, but it's even more complicated than that. To make the heart fit, the surgeon will first trim your new heart, so that it will synch up with the remaining parts of your old circulatory system. Then, they will sew the heart into place, so it won't be jostled around, especially during the remaining procedure.

Lastly, and most importantly, the surgeon will sew together every single blood vessel and check to make sure there are no leaks. This process is the most time-intensive part of the surgery, and surgeons genuinely specialize in heart transplants in order to do this right. There's a reason that heart transplants usually take up to six hours. 

The whole time a heart transplant is taking place, your body is going to know that something is going terribly wrong. Even under general anesthesia - even though you're unconscious, and you have a machine working for you - your body can still tell that something invasive is happening inside you. It knows your bones are being broken; it knows someone is cutting you. And it responds by sending a ton of antibodies to the site of the turmoil, and your immune system starts working overtime. 

In fact, internally, your body starts to hit panic mode and thinks you're sick. It tries to make sure you will not get an infection and that it's ready to fight off any foreign invaders. It also gets ready to prevent you from feeling pain by releasing endorphins. 

Once the surgeons decide that the heart is fully attached to you and won't move or come loose, they have to restart the flow of blood. To do this, the surgeons will take you slowly off of the bypass machine and begin restoring the direction of your blood through your new heart. This is done gradually, rather than all at once, and during this period your heart will likely start beating again all on its own. However, sometimes that doesn't happen. Sometimes your heart doesn't remember it's supposed to beat and won't connect with your brain correctly. 

To fix this, surgeons have to use electrical impulses to remind the heart that it has a job to do. They occasionally do that by electrocuting you, or rather directly electrocuting your heart. Luckily, this tends to do the trick, but it's no less of a frightening idea.