Programmed atrial pacing for orthostatic hypotension.

Programmable atrial inhibited pacemakers were implanted in two patients with orthostatic hypotension due to autonomic failure. They were paced at 95 beats/min during the day and programmed themselves to 55 beats at night. This treatment resulted in virtual disappearance of orthostatic symptoms during a two-year follow-up. Haemodynamic studies showed a mean increase in erect systolic blood pressure from 47 mmHg pre-implantation to 85 mmHg at nine months post-implant during pacing. Cardiac output averaged 3.0 l/min without pacing and 3.8 l/min with pacing at two investigations. Rapid heart rate and high supine blood pressure at night were avoided by programming the pacemaker.