San Antonio Express-News (Sunday)
Fibers could thread hearts back in rhythm
Two Texas scientists think they’ve found the best solution yet for treating irregular heart rhythms: a silky, threadlike fiber stitched into the damaged areas of the organ.
But this is no ordinary fiber. At just one-fourth the width of a human hair, it is filled with tens of millions of carbon nanotubes, which are great conductors of electricity.
These fibers were invented in 2013 by Matteo Pasquali, a Rice University professor. He teamed up with his friend, cardiologist Dr. Mehdi Razavi, to try applying them in arrythmia cases, in which the heart’s electrical system malfunctions and causes the organ to beat irregularly.
The heart is controlled by electrical signals, which tell the organ when to contract and relax. Scarred and damaged heart tissue won’t conduct enough electricity, however, and the fibers act as a bridge.
“They’re like extension cords,” Razavi, the director of Electrophysiology Clinical Research and Innovation at the Texas Heart Institute, said in an August 2015 Rice University news release announcing the project. “They allow us to pick up charge from one side of the scar and deliver it to the other side. Essentially, we’re short-circuiting the short circuit.”
So far, it’s worked — at least in preclinical models and rodents.
“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,” Razavi said.
More than 3 million cases of heart arrhythmia are reported in the U.S. each year. Many types are harmless, but some can result in a weak or damaged heart, causing potentially fatal symptoms.
While there are several ways to treat arrhythmias, they all have drawbacks, Razavi said. Medication can have bad side effects, he added, and ablation — a procedure in which the area of heart tissue causing irregular heartbeats is burned and destroyed — is destructive and decreases the amount of heart muscle in someone who already has heart issues.
Additionally, serious cases can be treated by an implanted defibrillator that shocks the heart in an effort to return rhythm to normal, but that can be incredibly painful, Pasquali said.
Though Pasquali and Razavi are encouraged by the results thus far, which were published this week in the American Heart Association’s Circulation: Arrhythmia and Electrophysiology, they’re several years away from human testing.
Scientists still need to ensure the fibers are strong and flexible enough to remain in the heart long-term. Pasquali and Razavi hope these fibers can last decades if needed. Carbon nanotubes are 100 times stronger than steel and one-sixth its weight.
They also need to develop a way to sew the fibers in place using a catheter. Luckily, the researchers will not be working from scratch in this regard. Many similar catheters already exist and may need only minor adjustments to be applicable here.
“This is a very big deal,” Razavi said. “Today there is no technology that treats the underlying cause of the No. 1 cause of sudden death, ventricular arrhythmias.”