Dr. Razavi inspects the carbon nanotube thread.

Rewiring the Heart to Repair Its Rhythm

Ventricular fibrillation, the most serious heart rhythm disorder, occurs when electrical signals can’t complete their journey across heart tissue, resulting in quivering heart muscles that fail to pump blood. This can lead to sudden cardiac arrest. But researchers have discovered a special type of thread that may offer a solution. 

How the Heart Pumps Blood 

Before we dive in, it’s important to understand how the heart works. The sinus node, a group of cells in the right atrium that acts as a pacemaker, creates electrical signals to send throughout the heart. These pulses then go to the top two chambers of the heart (the atria) and cause them to squeeze blood into the lower ventricles (the lower two chambers). The signal then moves to the ventricles, leading them to twist and contort to send the blood to the lungs and the rest of the body. 

Scar Tissue in the Heart Causing Ventricular Fibrillation 

Any type of trauma, whether it’s a heart attack or cardiovascular surgery, can create scar tissue in the heart. The electrical signals that the sinus node creates can’t travel through scar tissue. Instead, they arrive at the barrier between the scar tissue and the healthy tissue, and the signal doesn’t complete its path through the heart, which can prevent the heart from contracting. The force of the electrical signal arriving at the barrier causes ventricular fibrillation, a quivering motion that travels through the damaged area.  

How Researchers Are Bypassing Scar Tissue in the Heart 

When trying to move a signal over scar tissue, surgeons need a material that conducts electricity so the signal can travel and is flexible enough so it can move with the twisting motion of the heart and return to its normal position afterward. This is where carbon nanotubes come into play. 

Scientists manipulate gaseous hydrocarbons into carbon nanotubes and then process them into a thread. One of these threads contains a multitude of nanotubes and looks just like an ordinary string. However, surgeons can stitch these directly into the heart to create a bridge over scar tissue, allowing the signal to travel without interruption. 

“Our experiments provided the first scientific support for using a synthetic material-based treatment rather than a drug to treat the leading cause of sudden death in the U.S. and many developing countries around the world,” said Dr. Mehdi Razavi, Director of Electrophysiology Clinical Research and Innovations at Texas Heart® Institute at Baylor St. Luke’s Medical Center and co-leader of the study.

“Every time a cardiac surgeon opens you up and cuts, they have to suture,” he explained. “If that suturing is done on cardiac tissue, that’s a scar that blocks the conduction impulse. So if the chest is open and they have to close it with a suture anyway, why not use this thread?”

If you’re interested in learning more about innovative therapies for a variety of cardiovascular conditions, schedule an appointment with a CHI St. Luke’s Health cardiologist

Sources: 
TMC News | Repairing faulty electricity in the heart with conductive thread
Texas Heart Institute | Damaged hearts rewired with nanotube fibers
Heart Rhythm Society | Electrical System
MedicineNet | Medical Definition of Sinus node