Left ventricular outflow tract obstruction appearing in remote period of right ventricular septal pacing in patient with left ventricular septal bulge.

A woman in her 70 s presented with fatigue and dyspnoea during exertion. Six years ago, she had been implanted with a dual chamber pacemaker with the lead placement at the high septal site of the right ventricle. Echocardiography demonstrated the presence of the previously detected left ventricular septal bulge along with a newly observed systolic turbulent mosaic at left ventricular outflow tract (LVOT) and a systolic anterior motion (SAM) of the mitral valve. Electrophysiological pacing study and simultaneously performed echocardiography demonstrated that the apical pacing decreases the pressure gradient at the left ventricular outflow tract LVOT. We changed the lead position of the pacemaker from the high septal to the apical site of the right ventricle. During the follow-up period, recurrence of the obstruction at the LVOT with SAM was not detected. In the case with septal bulge, it is necessary to choose the apical position as the pacemaker lead placement.