Clinical Research
Clinical Research Papers
Non-Invasive Arterial Pulse
Waveform Analysis in Hypertension: Development of the Method, and
Early Compliance Changes in Subjects at Genetic Risk of
Hypertension
Kailasam MT, Brinton TJ, Wu RA, Hu G,
Chio S-S, Cervenka JH, Parmer RJ, O'Connor DT; UCSD and VA MC, La
Jolla, CA,and Pulse Metric, Inc., San Diego, CA.
Abnormalities
of arterial pulse wave and arterial compliance may occur early in
the course of essential hypertension. Such observations have
resulted from invasive waveform studies. We measured brachial
arterial compliance and peripheral vascular resistance in
essential hypertensives and their normotensive counterparts with
and without family history for hypertension, using a non-invasive
method to obtain large arterial pulse waveform from a simple
blood pressure cuff. With the DynaPulse we obtained data on 15
unmedicated essential hypertensives and 36 normotensives. Using a
simple mechanical model wherein the aorta was assumed to be a
"T" tube and the brachial artery a straight tube, we
derived peripheral resistance and compliance of the brachial
artery from arterial cuff waveforms. A significant correlation
occurred between distal compliance from DynaPulse waveform and
systemic compliance calculated by impedance cardiography (r=0.62,
p<0.001, n=38). In hypertensives, mean arterial pressure was
28 mmHg higher than in normotensives (p<0.001); hypertensives
had higher peripheral resistance (p<0.05) and lower compliance
(p<0.00l) than normotensives. In hypertensives, peripheral
resistance declined and arterial compliance improved (increase)
significantly following chronic therapy with antihypertensive
drugs such as ACE inhibitors (n=10) or calcium channel blockers
(n=8). Higher peripheral resistance (p<0.l) and lower arterial
compliance (p<0.05) were also found in still-normotensive
offspring of hypertensive parents (i.e., normotensives with a
positive family history for hypertension) compared to family
history negative normotensives. We conclude that arterial
compliance can be accurately assessed by non-invasive brachial
artery waveform analysis, and that compliance abnormalities may
reflect early structural changes in large arteries in subjects at
genetic risk of hypertension.
Key Words: Vascular compliance, peripheral resistance,
hypertension, waveform analysis.
*Presented at the American Society of
Hypertension Conference, 1994 (see American Journal of
Hypertension 1994 Vol 7, No.4, Part 2, pg. 86A).
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