Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New targeting technology improves outcomes for patients with atrial fibrillation

19.07.2012
UCLA-UC San Diego study findings point to a doubling of success in treating the heart-rhythm disorder, which affects more than 5 million Americans

In a landmark study of atrial fibrillation, researchers from UCLA, UC San Diego and Indiana University report having found for the first time that these irregular heart rhythms are caused by small electrical sources within the heart, in the form of electrical spinning tops ("rotors") or focal beats.

Importantly, they found a way of detecting these key electrical sources and of shutting them down in minutes using a precisely targeted therapy with long-lasting results.

The team, which included cardiologists, physicists and bioengineers, reports the findings in the July 19 issue of the Journal of the American College of Cardiology as part of the CONFIRM trial (Conventional Ablation for Atrial Fibrillation With or Without Focal Impulse and Rotor Modulation).

Currently, many atrial fibrillation patients treated with standard therapies will experience a recurrence due to the difficulty of finding the arrhythmia's source. The new research will help cardiologists better target and treat arrhythmias.

The CONFIRM study examined 107 patients with atrial fibrillation who had been referred for a non-surgical catheter ablation procedure. During this procedure, doctors thread a wire with a metal-tipped catheter through the body, from a vein in the groin to the heart, to apply heat to the area of the heart producing the arrhythmia to stop it.

In one group of patients, the team used the new technique to help perform very small, precise burns — called focal impulse and rotor modulation, or FIRM — that were aimed directly at the fundamental source of the arrhythmia: the tiny electrical disturbances in the heart called focal beats or 'rotors' that look like mini-tornadoes or spinning tops. Rotors can be likened to an "eye of a storm" shown in this study to cause atrial fibrillation. Remarkably, this new procedure shut down or very significantly slowed atrial fibrillation in 86 percent of patients in an average of just 2.5 minutes.

As a comparison, conventional catheter procedures were performed in a second group of patients. Since this approach is less targeted, it involved hours of treatment over larger regions in the heart and often did not shut down the atrial fibrillation.

To track outcomes, patients received an implanted ECG monitor that very accurately assessed their heart rhythms over time. The researchers found that after two years, the FIRM-guided group had an 82.4 percent freedom from atrial fibrillation episodes, compared with only 44.9 percent freedom in the group that received standard therapy.

The new targeted method demonstrated an 86 percent improvement over the conventional method.

"We are very excited by this trial, which for the first time shows that atrial fibrillation is maintained by small electrical hotspots, where brief FIRM guided ablation can shut down the arrhythmia and bring the heart back to a normal rhythm after only minutes of ablation," said lead author Dr. Sanjiv Narayan, a professor of medicine at UC San Diego, visiting professor at the UCLA Cardiac Arrhythmia Center, and director of electrophysiology at the San Diego Veterans Affairs Medical Center.

"The results of this trial, with an 80 percent ablation success rate after a single procedure, are very gratifying," said study author Dr. Kalyanam Shivkumar, director of the UCLA Cardiac Arrhythmia Center and a professor of medicine and radiological sciences at UCLA. "This is the dawn of a new phase of managing this common arrhythmia that is mechanism-based."

The science behind this work was funded by grants to Dr. Narayan from the National Institutes of Health (NIH grant numbers: HL70529, HL83359, HL83359-S1, HL103800), including a grant awarded as part of the American Recovery and Reinvestment Act, and by the Doris Duke Charitable Foundations.

From UC San Diego: These discoveries, owned by the Regents of the University of California, were then licensed to a startup company, Topera Medical, which has recently obtained clearance from the Food and Drug Administration for the mapping system it developed from this early science, called RhythmView.

Narayan is a co-founder with equity interest in Topera. Study author Wouter-Jan Rappel from the UC San Diego Department of Theoretical Biological Physics holds equity interest in Topera. Study author Dr. Shivkumar of UCLA is an unpaid advisor to Topera. Dr. John Miller, chief of electrophysiology at Indiana University, has received modest consulting fees from Topera.

Additional study authors included Dr. David Krummen, associate professor of medicine and associate director of electrophysiology fellowship training at the UC San Diego School of Medicine and associate director of the San Diego Veterans Affairs Medical Center, and Paul Clopton from the San Diego Veterans Affairs Medical Center Department of Statistics. They have no financial disclosures.

Rachel Champeau | EurekAlert!
Further information:
http://www.mednet.ucla.edu

More articles from Studies and Analyses:

nachricht Obstructing the ‘inner eye’
07.07.2017 | Friedrich-Schiller-Universität Jena

nachricht Drone vs. truck deliveries: Which create less carbon pollution?
31.05.2017 | University of Washington

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: 3-D scanning with water

3-D shape acquisition using water displacement as the shape sensor for the reconstruction of complex objects

A global team of computer scientists and engineers have developed an innovative technique that more completely reconstructs challenging 3D objects. An ancient...

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

Ultrathin device harvests electricity from human motion

24.07.2017 | Power and Electrical Engineering

Scientists announce the quest for high-index materials

24.07.2017 | Materials Sciences

ADIR Project: Lasers Recover Valuable Materials

24.07.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>