Slow Conduction Regions as a Valuable Vectorcardiographic Parameter for the Non-Invasive Identification of Atrial Flutter Types

The objective of this study is to non-invasively characterise a variety of atrial flutter (AFL) types, defined by a maroreentrant circuit. A vectorcardiographic approach is proposed to compare atrial macroreentrant circuits. Vectorcardiogram (VCG) arechetypes are computed so that parameters such as similarity among loops can be calculated. The methodology was employed in a set of artificial VCGs created from a computational simulation based on a mathematical model and in signals from real patients. Adenosine was used to block the ventricular contribution to the ECG signal, later transformed to a VCG analysed from different perspectives. Results demonstrate a high similarity for cases belonging to a group with its archetype in synthetic and real cases. Slow conduction velocity regions were found to be very well represented in VCGs, in accordance with AFL mechanisms and its importance when characterising atrial macroreentries. The conclusion is that our methodology allows differentiation between the most recurrent types of AFL through the analysis of its VCG representation, predicting the presence of slow conduciton regions along the macroreentry. This can be very useful when planning in advance the ablation procedure.