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We will optimize catheter design for the cure of atrial fibrillation
(AFIB) and ventricular tachycardia (VT) by radiofrequency (RF) ablation.In the USA about 2
million people are affected by some form of AFIB. Each year about 200,000
patients are treated for VT. Atrial fibrillation, although itself
not fatal, is a frequent cause of stroke and is linked to a high degree
of cardiovascular mortality. Ventricular tachycardia is the main cause
of sudden cardiac death, affecting particularly patients suffering of myocardial
infarction. Most commonly, drug therapy is recommended for atrial fibrillation.
Cardiac surgery has been used for curing atrial fibrillation in patients
undergoing open-chest surgery for other cardiac conditions. Although this
procedure can achieve sinus rhythm it is associated with significant morbidity
because of the need for open-chest surgery, and therefore cannot be recommended
as primary therapy. The use of implantable atrial cardioverter–defibrillators
is currently under investigation. Implantable ventricular cardioverter–defibrillators
are also used sometimes in patients with ventricular tachycardia. As we
will present in the next section, all these therapies have at least one
significant drawback. The medical community is currently searching for
a least invasive yet efficient therapy for these cardiac arrhythmias and
we argue that catheter ablation has the potential to fulfill this role.
RF catheter ablation has the potential of becoming the therapy of choice for atrial fibrillation. Preliminary studies report that the RF ablation approach has already had some success in curing atrial fibrillation in humans. To cure atrial fibrillation, the physician presumably would have to create, by RF ablation, long, thin lesions along trajectories similar to those postulated by the cardiac surgical maze operation which compartmentalize the atria so that fibrillation cannot occur. For the elimination of ventricular tachycardia occurring late after myocardial infarction, wide and deep lesions created by RF ablation may be needed. We will develop complex finite element (FE) models and perform experimental tests to optimize the design of ablation catheters capable of producing long thin lesions for the potential cure of atrial fibrillation (AFIB), as well as wide and deep lesions for the potential cure of ventricular tachycardia (VT). This study will develop complex finite element (FE) models and perform experimental tests to optimize the design of ablation catheters capable of producing long thin lesions for the cure of AFIB. It will also develop complex numerical models and perform experimental tests to optimize the design of ablation catheters capable of creating wide and deep lesions for the cure of VT. Experimental tests will validate temperature
and electric field distributions predicted by the swine FE models. Simulations
will find the optimal catheter design for the cure of AFIB and VT. These
tests will determine: (a) optimal electrode/catheter geometry; (b) optimal
placement of inner temperature sensors for the purpose of efficient temperature-controlled
RF ablation; (c) optimal power application and ablation procedure
duration. These findings will clarify the electrical-thermal response of
the catheter-tissue system during RF ablation. Experimental tests on swine
will verify the models.
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