University of Vermont

Vermont Advanced Computing Core

Spector's Research on Treating Heart Rhythm Disorder Earns Patent, Industry Agreement

Peter Spector, M.D.
UVM Professor of Medicine and cardiologist Peter Spector, M.D. (Photo: COM Design & Photography)

University of Vermont (UVM) cardiologist and heart rhythm specialist Peter Spector, M.D., is on a mission to improve the cure rate for a form of the most common heart rhythm disorder – atrial fibrillation (AF) – and has already earned a patent as he works towards this goal.

Roughly six to eight million cases of AF exist in the U.S., but despite its prevalence, medications only work in about 45 percent of patients. An alternative to medication exists; a procedure – called catheter ablation – is effective in about 75 percent of patients with intermittent (paroxysmal) AF, but the technique works poorly in the majority of AF patients, who suffer from a chronic form of the condition called persistent AF.

Spector’s three-year project – funded by a $1 million grant from Vermont residents Tom and Mary Evslin after Mr. Evslin was treated for a heart condition at The University of Vermont Medical Center – has yielded innovative technology that offers a potential new approach to catheter ablation of AF and led to creation of an impressive intellectual property portfolio. In addition, UVM has separately entered a collaborative research agreement with California-based Biosense Webster, Inc., the global leader in developing medical technology for the diagnosis and treatment of heart rhythm disorders.

Responsible for 20 percent of strokes, AF is characterized by irregular electrical activity of the atria – the upper chambers of the heart – and results in ineffective pumping action. AF can cause blood to pool in a portion of the left atrium and potentially clot, break loose, and migrate through the bloodstream to the brain, block an artery and cause an embolic stroke. Catheter ablation involves placing wires in the heart through the patient’s veins to apply controlled treatment in the form of radiofrequency energy to the heart, altering how electricity is able to flow. However, currently there is no approved catheter in the U.S. for persistent AF.

Identifying the “heart” of this rhythm disorder is challenging for electrophysiologists like Spector, and requires a deep understanding of the heart’s electrical system. He and colleagues at UVM developed a computer model of the heart’s electrical activity in order to study AF. Using their model, they believe they have identified what is responsible for perpetuating AF. They have also used their model to design catheters and a mapping system capable of locating the sites responsible for AF – creating a patient-specific targeting tool.

“If our therapy is even 10 percent more effective, it will help an enormous number of people,” says Spector.

“Under normal circumstances, organized waves of electricity spread through the heart. In AF, there is very turbulent electrical activity – “it’s like lots of tornadoes of electricity spinning through the heart,” says Spector. When the centers of these tornadoes run into an electrical boundary, such as a heart valve, they are extinguished; AF stops when all the tornadoes hit a boundary.

“As the condition evolves over time, these tornadoes become less likely to hit a boundary and the AF episodes last progressively longer. Electrophysiologists can offset this by building a boundary – an ablation line of scar tissue – which increases the probability of AF termination.

Spector’s research has shown that these tornadoes aren’t evenly spread through the heart.

“If you place your ablations at the locations where the tornadoes spin, you increase the probability that AF will stop,” he says. “However, if you put the lines in the wrong spot you actually make AF worse.”

This is why a tool which shows doctors where to ablate would be so powerful. Current tools are incapable of showing a sufficiently clear picture of how electricity spreads. But, says Spector, “It is the tissue’s electrical properties that determine where the cores will be. While we can’t study the properties of the tissue directly, our group has developed a way to examine how fast cardiac cells are being excited.” Because the tissue’s electrical properties determine how quickly cells can be excited, having access to this information gives doctors an indirect way to find the location of electrical tornadoes.

“Over the past nearly three years, Spector has worked with the UVM Office of Technology Commercialization to develop a patent portfolio of both U.S. and international patent applications covering the catheters, signal processing algorithms and other aspects of his research. He was awarded the first of these U.S. patents in November 2014, and as of January 2015, a second patent application has been allowed.

Spector also founded a private company – Visible Electrophysiology, LLC – in summer 2013, which focuses on the development of educational tools that use interactive modeling to enhance learning of clinical electrophysiology.

Through all of these efforts, Spector and colleagues hope to help the many patients suffering from chronic AF to maintain a regular heart rhythm, thus reducing their risk of stroke and providing them with a significantly higher quality of life.