Med Device Monday: Ablation Catheter

Atrial flutter, also known as atrial fibrillation, is a type of irregular heartbeat (arrhythmia). Rather than the heart resting between beats, the upper chambers never complete a full pump-relax-pump-relax cycle and instead do a somewhat steady quivering flutter. It can be asymptomatic or feel like the heart is thudding against the chest at an alarming rate. But, more than being unsettling in sensation, it can have longterm implications in the form of heart failure, stroke, blood clots, and other complications. 

This flutter happens when the electrical system in the heart doesn't function properly, whether because it was "built" that way or because of a cause like high blood pressure or coronary artery disease. As Healthline explains, "When you have AFL, the sinus node sends out the electrical signal. But part of the signal travels in a continuous loop along a pathway around the right atrium. This makes the atria contract rapidly, which causes the atria to beat faster than the ventricles. A normal heart rate is 60 to 100 beats per minute (bpm). People with AFL have hearts that beat at 250 to 300 bpm."

 Animation from washingtonhra.com.

Animation from washingtonhra.com.

A recently approved catheter device is able to help both diagnose and treat this condition. In a nutshell, the Blazer Open-Irrigated Ablation Catheter is inserted through a vein, targets the area that is producing the faulty electrical current, and then fixes it. Boston Scientific has several videos on the device, but I think FDA's explanation of the device is the most concise and easiest to understand:

"What is it? This catheter has an electrode on its tip and three electrode rings nearby. The catheter has a tube for cooling the tip with liquid during use. Doctors can bend the catheter so its tip can reach the place in the heart they need to treat.

When is it used? A doctor uses this catheter with other parts of a system to diagnose and treat a condition called type I atrial flutter. This flutter is an abnormal heart rhythm causing fast heartbeat. Persons with flutter have a wide variety of symptoms and a higher risk of stroke.

How does it work? A doctor puts this catheter through a puncture in a vein until it reaches the heart. The doctor uses information from the catheter system to find the place in the heart to treat the flutter. Then, the doctor sends radiofrequency energy to destroy the place that causes flutter. The doctor then takes the catheter out.

What will it accomplish? It can treat flutter and allow the heart to work better. In a clinical study doctors used this catheter to treat108 [sic] subjects. The flutter was corrected in 94 (87%) of them during the treatment. In 81 (75%) subjects, it remained corrected 3 months later."

 Photos from bostonscientific.com.

Photos from bostonscientific.com.

A heart valve flutter seems like such relatively small (in size, not in implication) and specific thing. It's incredible to think that even just a few decades ago we would have had no way of knowing what this condition was, never mind a relatively straightforward way to treat it.

There are so many conditions that affect just this one body part, the heart. In fact, we've already done posts on two different devices for two other heart conditions. One was on expanded use of a heart valve to treat aortic stenosis, and the other was on a small device to help close a specific type of hole in the heart. One of the things I love most about this work is seeing how people devote their time and resources to use technology to target specific problems. There are so many resources poured into each of these singular devices that will make a big difference in the lives of those they touch. I look forward to seeing what the future holds as technology continues to improve and advance our treatment abilities.

 

Further Reading:

Summary of Safety and Effectiveness Data

Approval letter