62 Gender effects on protein expression profiles related to arrhythmic phenotype in murine ventricles modelling catecholaminergic polymorphic ventricular tachycardia

Abstract

Objective We hypothesized that computed tomography-derived (CT) left atrial volume index (LAVI), in combination with other objective parameters, could be used to develop a score able to predict the presence of LVZs. Methods In a large cohort of patients undergoing their first AF ablations, comprehensive echocardiographic evaluations and cardiac CT were performed. During the electrophysiological studies, LA geometry and electroanatomic voltage maps were created. LVZs were defined as areas ≥1cm2 with bipolar peak-to-peak voltage amplitudes ≤0.5 mV. Results In a derivation cohort of 374 patients, predictors of LVZs were identified by regression analysis and used to build the ZAQ score (age≥65 years, female sex and CT LAVI≥57ml/m2). The ZAQ score of 2 points accurately identified the presence and the extent of LVZs (AUC 0.809, 95% CI 0.758-0.861, p<0.001; 3 cm2 [IQR 1.5-4.5] vs 7 cm2 [IQR 4-9], p 0.001). In a validation cohort of 103 patients, the predictive value of the score was confirmed (AUC 0.793, 95% CI 0.709-0.878, p<0.001; 4 cm2 [IQR 2-7] vs 11.5 cm2 [IQR 8-16.5], p 0.001). Conclusions The ZAQ score identifies LVZs and may be useful for planning the ablation strategy ahead of time (single shot PVI vs 3D mapping-guided ablation) regardless of whether the AF pattern is paroxysmal or persistent. Figure legend. Proposed AF ablation workflow independent of the temporal pattern of AF (ie. paroxysmal vs. persistent). (CT) Computed Tomography, (LAVI) Left Atrial Volume Index, (PVI) Pulmonary vein isolation. *Low voltage zones, if present, could be targeted with additional substrate modification ablation