Percutaneous autonomic neural modulation
A new approach to treating cardiac arrhythmias
Atrial fibrillation (AF) and ventricular fibrillation (VF) are common cardiac arrhythmias that do not have a uniformly efficacious or curative approach for their clinical management. Two-year efficacy rates with pharmacologic and ablative treatment or both are between 50 and 70 percent.
There is a pressing need for superior techniques to effectively treat these arrhythmias. AF affects more than 2.5 million patients annually and is associated with serious morbidity (stroke) and a $6.65 billion cost to the U.S. health care system. VF is the most common cause of death in the United States, affecting more than 450,000 patients annually.
As a result of suboptimal arrhythmia management techniques, the cardiac autonomic nerves have been intensely studied and clinically targeted to treat malignant arrhythmias.
Prior to the development of anti-anginal medications, coronary artery bypass grafting and percutaneous coronary interventions, sympathectomy was noted to relieve chronic anginal pain. Patients who have undergone heart transplantation with autonomic denervation of the heart do not develop AF. Cervical sympathectomy is an increasingly successful management option for VF, especially in patients with genetic arrhythmias.
Several procedures have been developed to target the autonomic cardiac nerves, but all involve either cardiac surgery or endocardial ablation, during which the cardiac muscle lying between the ablation energy source and the epicardial nerves is unnecessarily destroyed.
Prototype catheter development
Physicians at Mayo Clinic in Minnesota and Florida are evaluating percutaneous techniques developed in animal models to modulate the autonomic ganglia located on the epicardium. A series of prototype catheters and devices have been developed.
Next steps include a first in-human study of efficacy and safety of the approach and prototype catheters in patients undergoing open-chest cardiac surgery who have a high incidence of post-surgical arrhythmia. If successful, these preliminary clinical studies will lead to subsequent human studies using newly developed catheters and equipment via a percutaneous approach and compare their efficacy with existing techniques that attempt to decrease AF and VF.