Disappearance of orthostatic hypotension after pacemaker implantation in a patient with a long PR interval.

Orthostatic hypotension is the fall in blood pressure when upright and has a high prevalence in elderly population. Diagnostic and therapeutic work-up can be long and difficult. We describe the case of an 81-year-old male patient with long PR interval and episodes of 2:1 atrioventricular block, in whom the implantation of a dual chamber pacemaker led to the disappearance of orthostatic hypotension. The most likely mechanism was an impaired cardiac filling with a short diastolic time due to a very prolonged PR interval, a somewhat "pseudo-pacemaker syndrome". The correction of the first degree AV block with the implantation of the pacemaker and the optimization of the AV delay allowed us to correct the diastolic impairment and to resume a normal response to orthostatism. This case underlies the complex and multifactorial nature of orthostatic hypotension and the importance of a correct diagnosis of correctable causes to treat a very disabling condition.