Figure 1

Mapping LV lead positions. Example of the main screen of the software programme used for mapping LV lead positions. The longitudinal distance from the atrioventricular plane to the lead tip, in a base-to-apex direction, is quantified in mm using the 30° right anterior oblique fluoroscopic view (upper left hand panel). This longitudinal distance is transposed to the four-chamber CMR view (upper right hand panel), so as to determine the LGE-CMR short axis slice (yellow line, left lower panel) that corresponds to the LV lead tip position. The 30° left anterior oblique fluoroscopic view (right lower panel) is then used to determine the circumferential position (yellow arrow). The longitudinal and circumferential coordinates permit localization of the LV lead tip in relation to myocardial segments [35] and myocardial scars, which appear as white enhancement on LGE-CMR (white arrow).