Pacing stimulus to P-wave delay in a patient with a dual chamber pacemaker; An unusual cause of the pacemaker syndrome

We report the rare case of symptomatic A-V dys-synchrony due to pacing stim ulus to P delay in a patient with a dual chamber pacemaker. Seven months af ter the implant of a dual chamber pacemaker for intermittent complete heart block, a 76-year old man presented with worsening dyspnoea attributed to t he pacemaker syndrome. He was found to have a pacing stimulus to P-wave del ay of 160ms. As a result the P-wave occurred during ventricular systole lea ding to worsening dyspnoea. His symptoms improved with programming the AV d elay to 300ms.