The need for standardization of time- and frequency-domain analysis of body surface electrocardiograms for assessment of the atrial fibrillation substrate

Abstract

This editorial refers to ‘Measures of spatiotemporal organization differentiate persistent from long-standing atrial fibrillation’ by L. Uldry et al ., on page 1125 Despite some progress in the earlier decades, the current therapy of atrial fibrillation (AF) is still far from being satisfactory. Antiarrhythmic drugs can restore sinus rhythm only during the first few days after onset of the arrhythmia, are unable to effectively prevent recurrence of AF, and their use carries substantial risk of pro-arrhythmia. Catheter or surgical ablation therapy is effective in patients with paroxysmal AF, but its efficacy to cure persistent AF is still under debate. Moreover, AF ablation is afflicted with a number of potentially serious side effects. Preclinical as well as clinical investigations demonstrate that rhythm control therapy is more successful in individuals with low degree of structural remodelling in the atria. Structural heart diseases and AF itself cause cellular hypertrophy, interstitial fibrosis, inflammatory changes, and amyloidosis, which, in turn, lead to progressive electrical uncoupling between muscle bundles and conduction disturbances. Recent direct contact mapping studies in patients with AF have provided evidence that these alterations result in an increased incidence of conduction block and a higher number and smaller size of separate fibrillation waves.1 This enhancement in the complexity of the substrate for AF is regarded as the key mechanism underlying increasing stability of the arrhythmia in structurally remodelled atria.2 Thus, non-invasive tools for the assessment of AF complexity might be of value for better identification of patients in whom sinus rhythm can be restored and successfully maintained. Quantification of the AF substrate by advanced analysis of surface ECGs appears to be a logical step towards non-invasive quantification of the individual degree of electropathological alterations in the atria. The study by Uldry et al 3 . published in this issue of the Journal …