Effect of Age on Pulse Wave Velocity and
"Aortic Ejection Time" in Healthy Men and in Men
with Coronary Artery Disease
By ERNST SIMONSON, M.D.,
AND
K. NAKAGAWA, M.D.
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Method
We used an impedance plethysmograph developed by Dr. 0. H. Schmitt, Department of Biophysics, University of Minnesota.7 With this instrument, variations of the base line due to varying blood content between a pair of electrodes are
electronically eliminated. The record gives an
inertia-free reeording of the volume pulse due to
variation of impedance in an alternating current
circuit of 30,000 c.p.s., based on different conductivity of blood and surrounding tissue.
The aortie volume pulse was recorded from ani
electrode in the area of auscultation of the aortic
valve with the second electrode opposite it on the
back. Some exploration for the best location was
needed, the chest electrode being varied slightly
in the area of auscultation of the aortic valve. A
satisfactory record could be obtained within a few
minutes. The position of the back electrode was
not critical. The tracings from the aorta were taken
simultaneously with the 3 electrocardiographic
standard leads on a 4-channel Sanborn recorder.
For the plethysmographic recording of the femoral pulse, one electrode was placed on the palpable femoral artery at the femoral triangle. The
second electrode was placed opposite it on the
thigh. The femoral pulse was also recorded simultaneously with electrocardiographic leads I, II,
and III.
Impedance plethysmography is an indirect
method; the calibration, in terms of units of eleetrical resistance (1/100 Ohm), cannot be converted
into units of flow. This difficulty is not relevant to
the present study, however, in which only the foot
points of the aortic and femoral pulses were measured. The interval from the earliest QRS deflection
in any of the 3 standard leads to the foot point of
the aortic pulse ("aortic ejection time") and to
the foot point of the femoral pulse was determined.
The aortic pulse wave velocity (M./sec.) was calculated from the anatomic distance between the
electrode positions, divided by the interval between
the aortic and femoral pulse. The film speed was
50 mm./sec. (fig. 1).
Fifty-one healthy men were compared with 42
men with coronary artery disease. In the normal
group, absence of detectable disease was assured
T HE INCREASE of pulse wave velocity
with age is well established1-3 and reflects
a loss of the elastic properties of the arterial
wall.4 The age trends of pulse wave velocity
vary for different arteries.2 8 In view of early
localization of atherosclerotic changes in the
abdominal aorta, we have compared age trends
of the aortic pulse wave velocity, measured by
impedance plethysmography in normal subjects and in patients with coronary artery disease. Since arterial hypertension as well as age
increases the pulse wave velocity,1-6 only normotensive patients were selected for this series. Impedance plethysmography is a convenient method for inertia-free recording of
the aortic volume pulse from skin electrodes
and eliminates the necessity of intrapolation
of records from the subelavian or carotid
arteries as in earlier investigations.
We have also measured the interval from
the earliest QRS deflection in any of simultaneous 3 standard electrocardiographic leads to
the foot point of the aortie volume pulse recorded by impedance plethysmogram. This
interval consists of the electrical latent period, the period of isometric contraction, and
the time from the opening of the aortic valve
to the arrival of the pulse wave in the vicinity
of the aortic arch. The isometric contraction
time is probably the most important of these
components. The term "aortic ejection time"7
is used for abbreviation. The effects of age and
of coronary artery disease on this interval was
studied for the first time.
From the Laboratory of Physiological Hygiene,
University of Minnesota, Minneapolis, Minn.
Supported by Grant B 1859-C2, National Institutes
of Health, U.S. Public Health Service.
126
Circulation, Volume XXII, July 1960
PIJESE WAVE VELOCITY
Table 1
lye TH)tds/ oft -IoHi1,IEjecti(o
127
Ti[ee in Nortail
ti7/l Re0od((d
14
w411ith
ubj eotls (4( hio PoW
(444cC P14thlp~-mogrgI'aph
,
14?ped]
an
Age gr-oupl
8.1.)4ject
1
to '9
-IN
.IN. I
0.087
S.1).
0.014 ;
40 to 49
54) f-o 59
454) aI 14(1 44)01^
.12
0.098
l1(5
0.10(.3
I15
0. 1449
0.4(2
.1 8
(),() ]_
0.4 1 8
0. 1,9
'N
-N
.1).
tI
-N,
0.44145
0).( I ())f
49.025
ol7r)V'; \[A,i iel.:i
;
15
0. 1 271
(.015
SJD), sta4..nda,rd deisviatioll.
Downloaded from http://circ.ahajournals.org/ by guest on June 17, 2017
TImeill seconds ftrouit th1 olset (of the earliest
C(OlIplex of stalidt
1i51))l &tss'ls to the f)ot poiiit
th11 p 1let-11.v s 4o4g1r1
r44o0l(1 d It the .144)ti4 re at.
`(1 <(.05.
(f
4p <4(.t0 1.
4(1
thorou lgh
1
examin ation.
Jatientst
history of typil(al angina peetoris or- infairtietioni withl abiliiOllletl resting eleetrocordiog"isnls
11)1m oriuul el,ectro
e 1se51 pitli
spOll4l?s to
(is .:
^A11 UI)J ects i) 1 o)4th groul pli4s lia4l t1 4444(1
pressure of 14012 90
r I
er.
The age distribution of the 2 group)s is slhovii
in table 1. Onily the
groups ov et, 40 teatrs c11i
be coimipared (43 hea-Ilthy miten, 42 patieiits), sill4e
110 patie nits
ithi Vyo(i115 I-'V llItttrv\ dis42StslCe titdev 4))
Years were available.
1wv a
hiad
a
Figure
(4
ex
1I44)4
)W14
(/44/U
1ett)
4(44
1It
oft fb
(aNl,u
a1>?nd 1ff7.
t
ow
1,
1
4ny )/4r
of t11c (loa
(bottom
444c )44)a1l (11l/cr
(b ottm Ik, ligilt) si
n 44i ti t e/ 1,
//0 (1 di f t14
i
l J
/ /5
t/
r
(
sige
w
Results
F'igure
ity
iii
anid of
2 sihows the
mean J)tulse
lvt'¢)
wave
-
comiparable ag1e groups of healthly inent
those witlh coronI'ar-y di'sease. The lines
with asterisks con.ncectiug the grioup means
slhow the statstiesal signiiafi(-anec of ditferen(4'es
between age gronps id t:ile vertical linLes
show the statistical sirnificance of differ elnces
between patienits anmcd normnal- sub'jects of the
same age.
nrlie statistieal signifliance wais
evaluated by means of the t-test (' =p <0.05);
p
)
<0.01;
.001). Trhe changres
in the slopes of the cutrves are luld(IonLbte(lly
due to the reIltiv cly smaill. niuimiiber of sibj(-jects
iii eaclh ag,e group. Th'lie inereasing pulse wave
veloc ity ill the n,orm-X1al :ten c1onfil Irms p-reC-vious
results'6 andl the validity of the method. Thle
'Tlhe patienits
stud(lies by
Dr.
were
Hfeinry
of
gIroup usedi for other
0Bla-ockburn, Jr., at this LiTon
pIart
a
tor.v
(irculation, Votlitrut XXHI, July 1960
plLtse
velcocity alsoiiics
wtim.ii
I<ei
Io;{'Xf1Rpat icitts itli ( coronaryT diLease, but. the
iitieii,ts' va1lutes are higo-her ill all acegi,ronips.
Thlie (lifferen'et is g'reatest (an-d statistical
i-iifianee llig-hest) inI tlhe age group over 60.
Since tihe tge (distril4ntioil ill the healthiy
atnd
thes patie4ts is siiilar Compliarisoll of
t1e
vl
of t1e t atal
si over 40)
is jLustifed.
It is 6.78 21.
ini thle niorm al
gtIlrolup, and 8.41 21. sec. il the patielits. rhe
wave,
the
mci
nicait
see.
of 1 (iS A1..'see. is statistieally higlsignifican.t. If the
are arbitrarilv
smoothied out and age differences for the sante
p)lllse wave velocityr compared, ant average (lifferenlee of 18 yearsl is foun.d between tlhe
normal gioup atudl the platilets.
differenice
Ivy
curves
Table T
(21) and(i sta,n.ldard
ilvisations (SI)) of the naortie. electioni limet
ini the a(ge gronips of niormal men Calnld of patiejnts wvithi coromm-a-At aitery disease. 'fire, is
Sliglht eoltitil:ous inCr1ese of I lle ejeet4ion
soxvs
means
time with age in the iio-limlt-ial subjects
as
wNA.Tell
SIMONSON, NAKAGAWA
t28
oo<
o
f- )r tlIA )V
10
NORMAL
<>
LU
7
Z
6
/
LLI
5
4
20
30
50
40
60
70
Downloaded from http://circ.ahajournals.org/ by guest on June 17, 2017
MEAN AGE
Figure 2
Increase of mean aortic pulse wave velocity in normal subjects and in normotensive patients with
coronary disease with age. Lines with asterisks
show statistical significance between age groups
(-= p<0'05;
=
p<0O.I;
*'*
=
p<0.00l).
The
aortic pulse-wave velocity is significantly higher
in the patients.
in patients. The difference between the
youngest and the oldest normal group is statistically highly significanit (p - <0.01). The
aortic ej ection time is longer in all 3 age
groups of patients than in the sanme normal
age groups, and these differences are statistically significant.
as
Discussion
The higher aortic pulse wave velocity in patients with coronary disease than in normal
men of the same age probably reflects degenerative changes in the aorta with resultant exaggerated age trends. It is possible that an
increase of the aortic pulse wave velocity may
precede coronary insufficiency, since the aorta
is one of the earliest locations of atherosclerosis. In view of the simplicity of the methodthe aortic and femoral impedance plethysmogram takes about the same time as a conventional electrocardiogram-it is suitable for
large-scale clinical or epidemiologic exploration for early detection of atherosclerosis. The
present study, though encouraging, is only the
first step in this direction.
The "aortic ejection time " is physiologically not related to the pulse wave velocity but
is presented for the sake of brevity, since the
results were obtained with the same procedure
on the same subjects.
Prolongation of the "aortic ejection time"
with age cannot be due to the interval from
the opening of the aortic valve to the arrival
of the pulse wave beneath the electrode; the
age trend of the aortic pulse wave velocity is
opposite, and the time interval is too short to
be measured with precision. We may also assume that the electrical latent period is fairly
constant. The prolongation is therefore probably due to a prolongation of the isometric
contraction time with age. This information
could be directly obtained with cardiac catheterization, but impedance plethysmography
has the great advantage of simplicity, and
the avoidanee of discomfort, inconvenience, or
risk for the patient. The larger ilntervals in
patients with coronary artery disease may be
interpreted as some interferenee of the isometric contractioii bv mnyocardial isehemia or de-
generation.
The clhanges of pulse wave velocity as well
as those of the "aortic ejection time " in the
patients with coronary artery disease are in
the direction of normal age trends. This observation conforms, in general, to earlier experience in studies of peripheral eirculation6
and the electrocardiogram.8
Summary
Impedance plethysmogranms were taken in
51 healthy men and 42 normotensive men with
coronary heart disease from the aorta near the
place of auscultation of the aortic valve and
from the femoral artery in the femoral triangle recorded simultaneously with the 3
electrocardiographic standard leads.
The aortic pulse wave velocity was determined from the time interval between the foot
points of the aortic and femoral volume pulse,
and the anatomic distance between the electrodes. It increases with age in normal subjects as well as in patients, but the values are
significantly higher in the patients. These reCirculation, Volume XXII, July 1960
PULSE WAVE VELOCITY
129
sults are suggestive of accelerated degenerative changes in the aorta, probably due to
atherosclerosis.
The interval from the earliest detectable
QRS deflection to the foot point of the aortic
volume pulse ("aortic ejection time") becomes longer with age in the normal group.
In patients with coronary artery disease, the
prolongation is significantly larger for each
of 3 age subgroups. The results suggest that
ventricular ischemia affects ventricular isometric contraction.
e le puncto de base del pulso de volumine aortic
("tempore de ejection aortic") cresce con le etate
in le gruppo normal e in le patientes, sed in istesi.e. le gruppo de patientes con morbo de arteria coronarile prolongation es significativemente plus marcate in tres sub-gruppos de etate. Iste resultatos
suggere que ischemia ventricular affice le conitraction
isometric ventricular.
References
1. HALLOCK, P.: Arterial elasticity in man in relation to age as evaluated by the pulse wave
velocity method. Arch. Int. Med. 54: 770, 1934.
2. WEZLER, K.: Arterienelastizitait. Ztschr. Kreislaufforseh. 27: 721, 1935.
3. HAYNES, F. W., ELLIS, L. B., AND WEISS, S.:
Pulse wave velocity and arterial elasticity in
arterial hypertension, arteriosclerosis, and related conditions. Am. Heart J. 11: 385, 1936.
4. KRAFKA, J. JR.: Changes in elasticity of aorta
with age. Arch. Path. 29: 303, 1940.
5. EISMAYER, G.: Die Pulswellen-Geschwindigkeit
in versehiedenen Gefissgebieten, Ztschr. Ges.
Exper. Med. 96: 233, 1931.
6. SIMONSON, E., KoFF, S., KEYS, A., AND MINCKLER, J.: Contour of the toe pulse, reactive hyperemia, and pulse transmission velocity:
Group and repeat variability, effect of age,
exercise, and disease. Am. Heart J. 50: 260,
1950.
7. SCHMITT, 0. H.: Mechanism of the excitatory
process in biological systems. Office Naval Research Progress Report No. 24609.
8. SIMONSON, E.: The electrocardiogram in coronary
heart disease. Minnesota Med. 38: 871, 1955.
Summario in Interlingua
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In 51 homines normal e in 42 homines con normotension in le presentia de morbo coronari, plethysmogrammas de impedantia esseva obtenite ab le aorta
proxime al sito de auscultation del valvula aortic e ab
le arteria femoral in le triangulo femoral, in simultaneitate con le obtention del tres derivationes electrocardiographic standard.
Le velocitate del unda del pulso aortic esseva determinate super le base del intervallo de tempore inter
le punctos de base del aortic e del femoral pulso de
volumine, insimul con le distantia anatomic inter le
electrodos. Iste velocitate cresce con le etate, tanto
in patienltes como etiam in normales, sed le valores
es significativemente plus alte in le patientes. Iste
resultatos suggere le presentia de accelerate alterations degeneratori in le aorta, probabilemente in consequentia de atherosclerosis.
Le intervallo inter le prime detegibile deflexion QRS
9It
Age
To be seventy years young is sometimes far more cheerful and hopeful than to be forty
years old.-(To Julia Ward Howe on her seventieth birthday) By OLIVER WENDELL
HOLMES, M.D.
Circulation, Volume XXII, July 1960
Effect of Age on Pulse Wave Velocity and "Aortic Ejection Time" in Healthy Men
and in Men with Coronary Artery Disease
ERNST SIMONSON and K. NAKAGAWA
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Circulation. 1960;22:126-129
doi: 10.1161/01.CIR.22.1.126
Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231
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