How Radiation Therapy is Helping to Heal Irregular Heartbeats

Medical professionals are using a form of radiation used to treat cancer to help people with really serious heart conditions. It’s still an experimental solution, but the first tests look promising and it could change bad heart cells back into good ones like when we were younger.

Dr. Stacey Rentschler of Washington University in St. Louis said that an exciting thing might happen: It can actually make sick tissue better!

The kind of irregular heartbeat called ventricular tachycardia causes sudden cardiac arrest and kills about 300,000 people in the United States every year. To treat it, we need to use radiation which normally doctors try to avoid because it could hurt other parts of the heart too.

Researchers are ready to start a careful study to see if one, single dosage of medicine can help people with an irregular heartbeat and is safe enough – just like what happened when Jeff Backus was given the standard care.

The Louisville man already went through a very long, difficult surgery to help his heart beat properly. He also got a tiny machine put inside of him that acts like an emergency button. Later when winter came around, he fainted twice in one month and felt like someone kicked him in the chest – luckily the machine kicked in and saved him by shocking his heart back into its normal rhythm!

Backus said he was worried that a scary episode would happen again. He decided to take a chance on the experimental radiation treatment in February, and so far it’s been working well! It made him more hopeful about how things would turn out.

Your heart usually beats around 60 to 100 times a minute. If it starts beating too fast, it is called Ventricular Tachycardia. This happens when the electrical signals in your heart’s bottom chambers get messed up. It can be caused by damage from things like heart attacks.

Doctors sometimes use a procedure called “catheter ablation” to treat heart problems. They put long tubes in the heart, locate bad signals and burn them to make scars that block the bad signals. But some people are too sick for this, and for others like Backus, it does not work all the time.

Dr. Phillip Cuculich from Washington University came up with an idea where people don’t need an incision (cut their skin) during treatment.

The first step to finding a solution is a lot of careful testing. A patient will wear a special vest with 250 special pieces that measure their heart’s electrical activity and then the doctors will take scans to create an exact 3D map of any problems with the heartbeat.

To solve the problem Dr. Cuculich worked with someone named Dr. Clifford Robinson who specializes in using radiation carefully targeted to damage cancer and not hurt any healthy tissue around it.

Robinson said that he wasn’t trying to hit the heart specifically. His goal was actually to avoid striking the heart since some cancer survivors end up getting heart disease a while later as a result of radiation from tumors that reached and irritated their hearts.

At first, Robinson warned his arrhythmia patients about the potential risks that could occur many years in the future. One of them responded by saying they were more worried about what might happen the next day.

Patients need to stay in the same machine that is usually used to treat cancer. During this time, specific beams are sent to hit only one area and it only takes fifteen minutes.

In 2017 and 2019, Cuculich and Robinson had their breakthrough successes; they discovered some treatments that made sick people better. Even now, six years later, those patients are still doing well!

Despite not being approved yet by the Food and Drug Administration, two people have been given permission to treat around 80 additional people on a case-by-case basis. Some of those individuals, like Backus, are not as sick as earlier patients. The team from St. Louis has shared this technique with lots of other hospitals inside the U.S. and overseas that are trying it carefully.

The FDA needs more proof that radiation is useful and helpful to heart patients, however the more hospitals use it “off-label” the tougher it is to get this evidence. Now, a new study has been set up by Varian, where nearly 400 patients will either be given radiation or another type of treatment called catheter ablation so doctors can compare which one works best. Washington University just started looking for people who want to join, and other places will soon follow.

At first, the doctors didn’t know how exactly radiation could prevent irregular heartbeats. However, when they looked further, they realised that the radiation wasn’t causing any new scarring – which was really surprising and important. Plus, tests with real human and mouse hearts showed that this dose of radiation seems to help these misfiring cells heal themselves.

When parts of the heart muscle were zapped, certain genes that are normally dormant in adults were temporarily activated. One particular gene is called “Notch” and it helps a growing heart form its electrical system. Scientists think this reactivated pathway may help those areas keep working like they did when they were all younger. This could be an amazing discovery because there’s never been any treatment that could do this before.

Researchers are testing how human heart cells work in lab dishes and if really low radiation doses might be able to get rid of tumors. They want to make sure that these doses are safe and knowing what areas might need more attention is important.

The Health and Science Department of Big Big News is getting support from the Howard Hughes Medical Institute’s Educational Media Group. All of the content will be provided by the AP.