Figure 1: Intracardiac echocardiography (ICE) image of the interatrium septum demonstrating bowing of the midseptum by the Brockenbrough needle. Tenting of the interatrium septum by the Brockenbrough needle is seen, using a 10 MHerz ICE probe. Subject’s heart rate of 140 beats per minute without any arrhythmic response to this intervention.