Clinical Research
Clinical Research Papers
A New Technology to
Determine Circadian Blood Pressure and Arterial Compliance
Variations During Ambulatory Monitoring
Brinton TJ, Neutel JM, Walls ED, Chio
S-S, Smith DHG, Franklin SS, Weber MA, UCI, Orange, CA, and Pulse
Metric, Inc., San Diego, CA.
OBJECTIVE
To derive simultaneous blood pressure (BP) and arterial
compliance (C, ml/mmHg) measurements during a 24-hour period and
evaluate changing hemodynamics in circadian BP regulation.
METHODS
18 subjects, age 53± 3 years (9
treated hypertensives, 9 normotensives), underwent 24-hour
ambulatory BP and C monitoring using the DynaPulse 5000A.
Measurements were performed at 15 minute intervals during both
day and night. The new non-invasive device utilizes a cuff
sphygmomanomctcr to determine BP and C from analysis of the
oscillometric pulsation signal. C measurements are derived at MAP
(near-end systolic) in the cardiac cycle.
RESULTS
Average 24-hour blood pressure was 145/77 mmHg in
hypertensives and 136/73 mmHg in normotensives. However,
circadian BP variations had an inverse correlation with C in both
groups. Interestingly, C had the strongest correlation with pulse
pressure (PP) for each monitoring. The non-linear PP vs C
relation was best fit by a power function with average
correlation r = 0.78.
CONCLUSION
Results suggest that C and PP demonstrate a strong inverse
non-linear relation. Therefore, circadian blood pressure
regulation may be influenced by vascular function. Since
hypertension may affect BP regulation, the ability to evaluate
both BP and C should prove useful in both disease diagnosis and
treatment.
*Presented at the Italian Society of
Chronobiology Scientific Meetings, 1996.
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