Fig. 1From: Evaluation of five algorithms in predicting the sublocalisation of right ventricular outflow tract arrhythmia (RVOTA) when compared to 3D electroanatomical mapping originLeft and right panel ECGs showing a septal vs free wall origin of the RVOT ectopy based on Ito algorithm. In both panels, PVCs are characterised by a LBBB morphology with late transition in V4 and R/S ratio > 1 in lead II, III and AVF. The presence of QRS notching and the lower R wave amplitude in the inferior leads is highly suggestive for a free wall origin as in the right panel. Absence of QRS notching and higher R wave amplitude in the inferior leads suggest a septal origin of the PVCBack to article page