P1538Using high precision haemodynamic measurements to assess differences in AV optimum between different left ventricular lead positions in biventricular pacing. (20th June 2017) - Sohaib, S M A; Shun-Shin, M.; Wright, I.; Lim, E.; Moore, P.; Lim, PB.; Koa Wing, M.; Lefroy, D.; Linton, N.; Davies, DW.; Peters, NS.; Kanagaratnam, P.; et al.