Clinical Research
Clinical Research Papers
Arterial Compliance by Cuff
Sphygmomanometer: Application to Hypertension and Early Changes
in Subjects at Genetic Risk
Brinton TJ, Kailasam MT, Wu RA, Cervenka
JH, Chio S-S, Parmer RJ, DeMaria AN, O'Connor DT; UCSD and VAMC,
La Jolla, CA, and Pulse Metric, Inc., San Diego, CA.
Abnormalities
of the arterial pulse waveform reflect changes in cardiovascular
structure and function. These abnormalities may occur early in
the course of essential hypertension, even before the onset of
blood pressure elevation. Previous studies of cardiovascular
structure and function have relied on invasive intra-arterial
cannulation to obtain the arterial pulse wave. We evaluated
arterial structure and function using a noninvasive cuff
sphygmomanometer in hypertensive (n=5) and normotensive (n=36)
subjects, stratified by genetic risk (family history) for
hypertension. Using a simple physical model in which the aorta
was assumed to be a T tube and the brachial artery a straight
tube, we determined vascular compliance and peripheral resistance
by analyzing the brachial artery pulsation signal from a cuff
sphygmomanometer. Essential hypertensive subjects tended to have
higher peripheral resistance (P=.06) and significantly lower
vascular compliance (P=.001) than normotensive subjects. Vascular
compliance correlated with simultaneously determined pulse
pressure in both groups (n=51, r=.74, P<.0001). Higher
peripheral resistance (P=.07) and lower vascular compliance
(P=.04) were already found in still-normotensive offspring of
hypertensive parents (ie, normotensive subjects with a positive
family history of hypertension) than in normotensive subjects
with a negative family history of hypertension. Multivariate
analysis demonstrated that both genetic risk for hypertension
(P=.030) and blood pressure status (P=.041), although not age
(P=.207) were significant predictors of vascular compliance
(multiple R=.47, P=.011). However, by two-way ANOVA, genetic risk
for hypertension was an even more significant determinant
(F=7.84, P=.007) of compliance than blood pressure status
(F=2.69, P=.089). Antihypertensive therapy with
angiotensin-converting enzyme inhibitors (10 days, n=10) improved
vascular compliance (P=.02) and reduced resistance (P=.003)
significantly; treatment with calcium channel antagonists (4
weeks, n=8) tended to improve vascular compliance (P=.07) and
significantly reduced peripheral resistance (P=.006). We conclude
that arterial vascular compliance abnormalities detected by a
noninvasive cuff sphygmomanometer reflect treatment-reversible
changes in vascular structure and function. Early changes in
vascular compliance in still-normotensive individuals at genetic
risk for hypertension may be a heritable pathogenetic feature of
this disorder.
Key Words: Compliance, peripheral resistance, genetics,
angiotensin-converting enzyme inhibitors, calcium channel
antagonists.
*Published in
Hypertension
, 1996 Vol 28,
No.4, pp. 599-603.
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