Nanoparticles Yield Big Results.

The efficacy of catheter ablation has improved dramatically over the past 3 decades as our understanding of ablation lesion formation has led to technological advances that have resulted in the ability to reliably create large and deep lesions. In the early years, operators were constrained during radiofrequency (RF) ablation with 2-mm nonirrigated electrodes by the tendency for the electrode–tissue interface temperatures to exceed 100°C resulting in boiling of blood and the formation of coagulum and char. Adherent coagulum reduces available electrode surface area resulting in a progressive and rapid rise in impedance and requires cessation of energy delivery. Thus, the magnitude of power that can be delivered to the tissue is limited. Because larger ablation electrode tips and irrigated electrode tips were introduced, electrode–tissue interface temperatures were lower, allowing the operator to ablate with higher powers and create much larger lesions. Presently, large ablative lesions can be created with a variety of technologies including irrigated RF ablation with force sensing, ultrasound ablation, and laser ablation. But despite these advances in lesion science, there are still some ablation targets such as the critical substrates for the propagation of reentrant ventricular tachycardia that are sometimes beyond our reach.