Validation of a telemetry system for long-term measurement of blood
pressure.
Brooks, Dina, Richard L. Horner, Louise F. Kozar, Thomas K. Waddell,
Caroline L. Render, Eliot A. Phillipson.
Department of Medicine, University of Toronto, Toronto, Ontario,
Canada, M5S 1A8
APStracts 3:0150A, 1996.
We have used an implanted telemetry system to continuously monitor
blood pressure (BP) in three dogs for durations ranging from 28 to 75
weeks after implantation. Measurements of BP obtained by telemetry
were compared every 3 to 12 weeks with measurements of BP recorded
with a manometer-tipped catheter that was inserted into a femoral
artery. Over a wide range of both physiological and pharmacologically
manipulated pressures (40-200 mm Hg), the values of BP obtained by
the two methods were highly correlated (all r>0.966; all p<
0.0001). However, the mean differences between the values obtained by
the two systems were different than zero (range, +29.6 to -1.5 mm Hg;
p<0.0001) indicating an offset in the BP values recorded from
the implanted system. Furthermore, this offset was dependent on the
absolute level of BP. The findings indicate that, for a period of at
least 28 weeks and up to 75 weeks following implantation, the
telemetry system accurately measures acute changes in BP, and can
reliably measure absolute BP provided that the system is properly
validated.
Received 27 October 1995; accepted in final form 21 February
1996.
APS Manuscript Number A1147-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 27 March 96