Apparent acute reversible right ventricular pacing-induced left ventricular dysfunction.

We report the case of a 70-year-old Caucasian male with a dual chamber (right atrium/right ventricle) pacemaker implanted for sinus node dysfunction and not pacemaker (PM) dependent who was found to have an apparent acute worsening of left ventricular (LV) function with right ventricular (RV) apical pacing caused by the mode switch to VVI pacing as battery depletion occurred. LV dysfunction resolved immediately with RV pacing turned off. To our knowledge, this is the first report of this phenomenon.