Automatic cuff inflation during ambulatory blood pressure monitoring does not attenuate night-time hypotension and bradycardia

One of the problems that characterizes automatic blood pressure (BP) monitoring is that the intermittent inflation of the arm cuff may disturb sleep and therefore prevent accurate description of the magnitude and extent of nocturnal hypotension and bradycardia. We have addressed this issue in 17 patients with mild-to-moderate hypertension, in whom ambulatory BP was monitored intraarterially for 48 hours by the Oxford technique. During the first or the second 24-hour monitoring period, BP was also monitored noninvasively from the contralateral arm by the Spacelabs 5300 (n = 10) or by the Sandoz Pressure System SPS 1558 (n = 7) devices. Automatic BP measurements were programmed every 15 minutes during the day an every 30 minutes during the night. Separate computer analysis of the two 24-hour intra-arteria tracings obtained with and without the concomitant presence of the noninvasive ambulatory BP monitors, showed that the day-night intra-arterial BP and heart rate profiles were unaffected by the occurrence of repeated automatic cuff inflations. These data suggest that these devices do not prevent careful assessment of circadian BP and heart rate variations.