Fine tuning cardiac ablation could lead to quicker results for patients with arrhythmias

July 24, 2012
University of Michigan chemists and physicians examine a new method for targeted cardiac ablation that could lead to quicker results for patients with arrhythmias. Credit: University of Michigan Health System

University of Michigan heart researchers are shedding light on a safer method for steadying an abnormal heart rhythm that prevents collateral damage to healthy cells.

, or arrhythmias, set the stage for a common, debilitating disorder called atrial fibrillation that puts adults as young as age 40 at risk for fatigue, fainting, cardiac arrest, and even death. Medications can help, but doctors also use catheter ablation in which are delivered to a region of the heart to disrupt the arrhythmia.

However, studies show half of patients require more than one ablation to see results. In a laboratory study, the U-M used photodynamic therapy, a technique long used in cancer research, to disrupt the specific cells causing the arrhythmia.

The study suggests cell-specific cardiac ablation could help patients avoid complications, and get closer to an arrhythmia-free life without having to undergo repeat hospital visits.

Chemists in the U-M Department of Chemistry and electrophysiologists at the U-M Center for Arrhythmia Research collaborated on the study that will require further examination before it is available in the hospital setting.

"This cell-selective therapy may represent an innovative concept to overcome some of the current limitations of cardiac ablation," says lead study author Uma Mahesh Avula, M.D., research fellow at the U-M Center for Research.

The study was published online ahead of print in the September issue of the Journal of Heart Rhythm.

The heart consists of different types of cells such as myocytes, fibroblast, adiopocytes and purkinje fibers, which are all needed for normal cardiac activity.

The new study is the first of its kind to use photodynamic therapy and nanotechnology to ablate only the responsible for arrhythmias. In current ablative techniques, all receive ablative energy, which can lead to complications such as puncturing the , bleeding or stroke.

"Current ablation techniques are severely limited by its non-specific nature of cellular damage. Besides this lack of cellular discrimination markedly increases the required energy amounts and prolongs procedure times, all of which reduces overall ablation results," Avula says.

has emerged as an important treatment option that requires careful assessment, planning and execution for optimal success rates. Advances over the past 20 years have made the treatment safer, but it remains highly complex.

"Approaches that could simplify and shorten the procedure may contribute to more patients being treated," Avula says.

Rather than radiofrequency energy, the most common type used in , the U-M team introduces the use of PDT in cardiac electrophysiology to target specific cell types. Targeted PDT, which was pioneered in the labs of study senior author U-M chemist and engineer Raoul Kopelman, Ph.D., is extensively used in cancer research for selectively killing cancerous cells.

The disruption induced by PDT is confined to cells that have been photosensitized, while adjacent non-photosensitized cells are unaffected.

"We think this approach will decrease the extent of unwanted cell injury, inflammation, and ablation-related tissue damage, and pave a way for the development of more effective therapies for cardiac arrhythmias," says study senior author Jérôme Kalifa, M.D., Ph.D., assistant professor of internal medicine at the U-M Health System.

Explore further: Freeze and desist: Disabling cardiac cells that can cause arrhythmia

More information: "Cell-specific nanoplatform-enabled photodynamic therapy for cardiac cells," Journal of Heart Rhythm, dx.doi.org/10.1016/j.hrthm.2012.05.011

Related Stories

Freeze and desist: Disabling cardiac cells that can cause arrhythmia

September 12, 2011
Many patients are responding to a new, minimally invasive way of treating irregular heartbeats by freezing out the bad cells. Atrial fibrillation (A-Fib) is one such heart rhythm disorder, and it's the most common arrhythmia ...

New targeting technology improves outcomes for patients with atrial fibrillation

July 18, 2012
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 ...

UCSD uses heat energy to fix odd heart beat

February 17, 2012
(Medical Xpress) -- UC San Diego Sulpizio Cardiovascular Center is now offering patients with atrial fibrillation the breakthrough benefits of heat energy, or radio frequency waves, to irreversibly alter heart tissue that ...

Recommended for you

Laser device placed on the heart identifies insufficient oxygenation better than other measures

September 20, 2017
A new device can assess in real time whether the body's tissues are receiving enough oxygen and, placed on the heart, can predict cardiac arrest in critically ill heart patients, report researchers at Boston Children's Hospital ...

Metabolism switch signals end for healing hearts

September 19, 2017
Researchers have identified the process that shuts down the human heart's ability to heal itself, and are now searching for a drug to reverse it.

Beta blockers not needed after heart attack if other medications taken

September 18, 2017
A new study from the University of North Carolina at Chapel Hill finds beta blockers are not needed after a heart attack if heart-attack survivors are taking ACE inhibitors and statins. The study is the first to challenge ...

Which single behavior best prevents high blood pressure?

September 15, 2017
(HealthDay)—You probably already know that certain healthy lifestyle behaviors can reduce your risk of developing high blood pressure, but is any one behavior more important than the others?

RESPECT trial shows closing a small hole in heart may protect against recurrent stroke

September 13, 2017
A device used to close a small hole in the heart may benefit certain stroke patients by providing an extra layer of protection for those facing years of ongoing stroke risk, according to the results of a large clinical trial ...

Study shows so-called 'healthy obesity' is harmful to cardiovascular health

September 11, 2017
Clinicians are being warned not to ignore the increased cardiovascular health risks of those who are classed as either 'healthy obese' or deemed to be 'normal weight' but have metabolic abnormalities such as diabetes.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

danwalter2012
not rated yet Jul 24, 2012
Catheter ablation for afib is a corporate-driven procedure which is riskier and less effective than advertised: Google "Collateral Damage: A Patient, a New Procedure and the Learning Curve"

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.