Effects of atrial tachypacing on symptoms and blood pressure in severe orthostatic hypotension.

ABSTRACT

UNLABELLED The treatment of severe orthostatic hypotension (OH) is currently unsatisfactory and usually includes various pharmaceuticals to expand the blood volume and promote peripheral vasoconstriction. This study examined the short- and intermediate-term effects of atrial tachypacing (ATP) in patients with severe OH. We implanted dual chamber pacemakers in five patients (mean age 64 +/- 7 years; four men), presenting with drug refractory, recurrent syncope, and OH due to panautonomic failure with severe chronotropic incompetence and absence of rate acceleration upon assuming the upright posture. The blood pressure (BP) was measured in the supine and passive upright postures, during sinus rhythm, and during atrial pacing at 90, 100, and 110 ppm, at 1 week and at discharge and/or 3 months after pacemaker implantation. Alleviation of symptoms and a delay in the fall in upright BP were observed in a single patient at 1 week, while at discharge and/or 3 months, all patients were markedly improved. The mean fall in systolic/diastolic BP between supine and upright position decreased from 73 +/- 17/46 +/- 13 mmHg before, to 56 +/- 27/41 +/- 30 mmHg during ATP. Although these changes did not reach statistical significance, the time required for the fall in BP lengthened significantly from 2.1 +/- 0.2 minutes during sinus rhythm to 9.3 +/- 1.5 minutes during ATP (P < 0.001). CONCLUSIONS: At discharge and/or 3 months of follow-up, ATP conferred beneficial effects on orthostatic BP and alleviated symptoms in patients with severe OH. The short-term effects of ATP did not reflect its longer-term effects in four of the five patients.