Demonstrating the Value of Contact Force Sensing: More Difficult Than Meets the Eye
Catheter ablation of atrial fibrillation is a widely accepted and commonly performed procedure worldwide. During the almost two decades that have passed since first identification of the pulmonary veins (PVs) as a common site for focal triggers that initiate atrial fibrillation (AF), catheter ablation of AF has matured. AF ablation is now recommended as a Class 1 therapy for treatment of patients with symptomatic AF refractory to at least 1 membrane active antiarrhythmic medication1-3. Despite the well-established track record of safety and efficacy of AF ablation, its outcomes remain an imperfect. Major complications occur in 1% to 5% of patients, and single procedure efficacy disappoints us - even when the procedure is performed in "optimal" young healthy individuals with paroxysmal AF. It is widely acknowledged that "touch-up" procedures will be needed in 30% - 50% of patients4,5. When a repeat AF ablation procedure is performed, reconnection of 1 or more PVs is the rule6,7. Creation of more permanent RF lesions would be a major step forward in combatting the problem of reconnection of the PVs and hopefully in improving efficacy. RF lesion size is impacted by power, duration, and contact force (CF). Until recently only the first two in this triad could be measured and controlled8. The good news is that over the past several years two different RF ablation catheters capable of monitoring contact force have been developed9-11. The first of these was evaluated as part of an FDA approval process in a non-randomized study11. This catheter met its endpoint of being equivalent to a commercially approved irrigated RF ablation catheter. But only after a post- hoc analysis could the value of CF monitoring be seen. Of even greater disappointment was that 4 of 161 patients (4%) experienced cardiac tamponade, a complication we had hoped CF monitoring would reduce.
- Received July 25, 2015.
- Accepted July 28, 2015.