Determining the origin of the ectopic beat in idiopathic ventricular arrhythmia with a computational model

Autores UPV
Año
CONGRESO Determining the origin of the ectopic beat in idiopathic ventricular arrhythmia with a computational model

Abstract

Purpose: Idiopathic arrhythmias require long procedures to acquire invasive electro-anatomical maps and ascertain the right ventricular (RV) or left ventricular (LV) origin of the ectopic beat. A recent study suggests a correlation between the shape of the activation-map isochrones in the RV outflow tract (RVOT) and the origin of the ectopic beat. We propose to study and validate this relationship with a computational model. Material and methods: A detailed anatomical model of the LV and RV including the outflow tracts was built from a magnetic resonance image of a patient. A finite element mesh was then generated where myofibre architecture was synthetically introduced. Electrophysiological simulations were performed for 150ms after the ectopic beat. Four different origins of ectopic beats were analysed: the left (LV-LAC), non-coronary (LV-NCAC) and right (LV-RAC) aortic cusps; and the middle of the RVOT. A post-processing step was implemented to derive 20msisochrones around the earliest activated area in the RVOT and their shape was characterized (area, axis ratio computed as the maximum over minimum diameters of the isochrones). Results: The axis ratio and area indices characterizing the 20ms-isochrones for the four different configurations were: 2.43 and 2.25 cm2 for LV-LAC; 1.74 and 2.55 cm2 for LV-NCAC; 1.16 and 2.95 cm2 for LV-RAC; 2.59 and 1.18 cm2 for RVOT origin. The earliest activated area in the RVOT appeared 100 ms, 150 ms, 70 ms and 3 ms after the ectopic beat for LV-LAC, LV-NCAC, LV-RAC and RVOT, respectively. Conclusions: The developed computational model reproduces the electrical activation patterns observed in clinical data, clearly identifying larger isochronal areas and smaller axis ratios with LVOT rather than RVOT origin of the ectopic beat.