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.
Irregular heart rhythms, 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 electrical impulses 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 Arrhythmia 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 cardiac myocytes responsible for arrhythmias. In current ablative techniques, all cardiac cells receive ablative energy, which can lead to complications such as puncturing the heart muscle, 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.