University of Vermont

Research at The University of Vermont

Customized Treatment for the Most Common Heart Rhythm Disorder

PETER SPECTOR, M.D., PROFESSOR OF MEDICINE

As a cardiologist, Peter Spector, M.D., has seen his share of patients suffering from the nation's most common heart rhythm disorder, atrial fibrillation (AF). AF is characterized by extremely irregular and fluctuating heartbeat and is responsible for up to a 24 percent increase in a patient's risk of stroke, and as much as a two-fold increase in the risk of death. But Spector has often felt powerless to help patients with advanced cases of AF.

The current treatments — medication and catheter ablation — are inadequate. In fact, most AF patients are not candidates for ablation, which uses targeted application of heat to change how electricity flows through the heart. Of the AF patients who are candidates for ablation, only about 75% see a cure. In the most advanced cases the success rates for ablation can be less than 50%.

In patients with simple abnormal heart rhythms, ablation has a high success rate because doctors can more easily record the heart's electrical activity and understand where to place catheters for the most effective outcome. In AF patients, however, the heart's rapid and disorganized electrical activity makes it difficult for doctors to interpret electrical recordings, draw conclusions, and understand how best to guide the procedure.

As a researcher, Spector aims to improve on the one-size-fits-all approach toward ablation. He is developing better mapping of the electrical activity and structure of an AF patient's heart via electrical recordings and CT scans. Through this improved mapping, doctors can more effectively target the sites in the heart that need to be addressed and deliver patient-specific treatment.

Over several years, Spector has developed a method of analyzing electrograms to determine the density of rotors, or rapidly firing reentrant circuits, in the heart tissue of AF patients. The insight he has gained has allowed him to better understand why medications in AF patients stop working; why ablation is effective in early AF but not in more advanced AF; why medications sometimes work after an unsuccessful ablation but not before; why AF is common shortly after a successful ablation; and why AF is common after cardiac surgery.

Spector's research could result in significant increases in the rate of cure in AF patients. With AF creating an enormous burden on patients and the health care system, improving treatment would not only save lives but also would hold down costs. The significance of his research caught the attention of philanthropist and one-time heart patient Tom Evslin, who, with his wife, Mary, donated $1 million to support the scientific and clinical aspects of Spector's project. This work has now led to development of a new catheter and mapping approach to identify which areas in the heart should be targeted during an ablation for patient-specific ablation therapy.

In addition to establishing one of the leading electrophysiology programs in the nation, Spector has created a spinoff company, Visible Electrophysiology, LLC. With UVM bioengineer Jason Bates, Ph.D., Spector co-developed software that models the electrical behavior of the human heart, making it an effective tool for medical education and research applications. In their recent publication in the journal Circulation: Arrhythmia and Electrophysiology, Spector and Bates report the improvements they have made in training for electrophysiology. An editorial in a major electrophysiology journal has highlighted the article as recommended reading for cardiologists and researchers.

Last modified May 19 2014 03:55 PM