While experimental and human mapping studies have documented multiple wavelet reentry as the electrophysiological mechanism maintaining atrial fibrillation, recent evidence shows that nearly all paroxysms of atrial fibrillation are initiated by trains of rapid discharges from the pulmonary veins. Radiofrequency catheter ablation targeting these initiating triggers has resulted in an overall 69% freedom from atrial fibrillation at a follow-up of 8 +/- 4 months in a population of 110 patients with paroxysmal atrial fibrillation. Six of the targeted pulmonary veins (4%) developed pulmonary vein stenosis; none requiring specific treatment. Catheter ablation of pulmonary vein foci initiating atrial fibrillation is therefore an effective curative modality for paroxysmal atrial fibrillation.
For physicians who are not familiar with the electrical basis of cardiac stimulation, high impedance leads previously (10 years ago) considered as bad electrodes (high voltage) are now considered as the 'epitome' of lead technology (low energy drain): clearly impedance is not a good parameter for characterizing the qualities of a pacing lead. Using a simplified approach to the electrostimulation 'paradigm', it is easy to establish that modern high impedance leads are in fact high current density leads and high efficiency leads (better description). It is also possible to establish that routine programming of the safety margin at 100% above threshold parameters is associated with a decrease in the penetration of the electric field according to the reduction of the cathode surface area. For safety and energy saving, a small tip electrode could be combined with a low polarization surface treatment and a reduction in fibrosis development between electrode and myocardium.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.