1639
JACC Vol. 23, No. 7
Jane 1994: 1 63 8-43
NEW METHODS
Validation of Continuous Wave Doppler-Determined Right
Ventricular Peak Positive and Negative dP/dt : Effect of Right Atrial
Pressure on Measurement
TOSHIO IMANISHI, MD, SATOSHI NAKATANI, MD,* SACHIKO YAMADA, MD,
NORIFUMI NAKANISHI, MD, SHINTARO BEPPU, MD, SEIKI NAGATA, MD,
KUNIO MIYATAKE, MD, FACC
Osaka, Japan
t76Jecfives . The present study aimed to validate the peak
positive and negative values of the first derivative of right veabk.
War pemure (dP/dt) using Doppler y and t deterb.
mine
impart ntright Mew pe rave a the uw
Backgrouat. A pressure -radleut betwaw the right ventricle
end the right atrium cmm be obtained by condenons wave Doppler .
derl eel tricuspid regurginM velocity udag the simpfifed Ber .
lath equaded . If right nerhal pressure gndnaden daring systole
and buntha k daerok were small compared with right c trig •
star pressure changes, right ventricular pressure could be evil, .
Med, and maximal poelive and negative dP/dt could aim be
determined with Doppler echocardiography .
Methods. We ivestignted 11 patient whoa wide ras~drkht
suit pressure ;9th tricuspid regurghlltlen wing shinshitmetia;
aaminada by Doppler uhramund and atheteriradon . Hems
dynamic codidam were altered by the Vdwlva maneuver, and ∎
total of 40 hens were analyzed.
The peak value of the first derivative of the intraventricular
pressure (dP/dt) is one of the most useful indexes for
assessing ventricular function (1,2) . However, determinations of the instantaneous rate of ventricular pressure change
require an invasive high fidelity pressure recording system
employed at cardiac catheterization and therefore are not
suitable for repeated assessment.
In mitral regurgitation, continuous wave Doppler echocardiography provides an accurate determination of the
instantaneous left ventriculoatrial (VA) pressure gradient by
use of the simplified Bernoulli equation (3). Because left
atria) pressure variations during systole and isovolumic
From the Cardiology Division of Medicine. National Cardiovascular
Center, Osaka, Japan. This work was supported in pan by a Research Grant
Far Cardiovascular Diseaszs (SA.7) from the Minisry ofHeellh and Welfare of
Japan, Tokyo, Japan.
Manuscript received September 17, 1993; revised manuscript received
January 3, 1994, accepted January 12, 1994,
.Present address and address fororrespo de ce ; Dr. Sa,Oshi Nakataw.,
tlepadment of Cardiology/Desk F15, The Cleveland Clinic Foundation, 9500
Euclid Avenue, Cleveland, Ohio 44195.
01994 by the Arced- College of Cardiology
Resin. There was good correiatbo between DoppW-desired
and cateterlratloaderived peak poultice dP/dt (y = 1 .0% - 15.4,
r = 0.98, n = 40), krespective of the level of right ahlal pressure.
Doppler-deelved peak negative dP/d also slowed good correlation with that determined by dieteriziOOn (y = 0 .9n + $8.2,
r = 0.93, a = 40). However, In pod" with high right Metal
prmme (v wave pressure a10 mm Hg), Depplerderived peak
negative dP/dt tended to show lower vales than thane from
cWeteriuiien meumremsw, except i pnimb With Pob--*
byperleweten,
Coarlariu. We conclude dot right vlmMedm dP/dt can be
estimated by lie Doppler method -em** and nenMruirdy .
However, when right aerial ptuaee Is reYiw6y high , npud
veth oorrespomdl4 right venlrirdm pnmme choya brig
iovalatee dlmtele, Deppierdahd pads nIV"ve WIN might
underefflaate cMiekrderl d mrrmemeW .
(j Am Cad Crdei 19N;23:1413-43)
diastole are considered relatively minor compared with left
ventricular pressure variations, the first derivative of the
Doppler-derived VA pressure curve and of the left ventricular pressure curve should be identical . Thus, recent studies
have shown that left ventricular peak negative as well as
peak positive dP/dt could be accurately estimated noninvasively using the Doppler method (4-6).
In contrast, Doppler-derived dP/dt has not been well
validated for the right ventricle (7) . Right VA pressure
gradients can be obtained using continuous wave Dopplerdetermined tricuspid regurgitation velocity (8,9) . Therefore,
if right atrial pressure and its fluctuation during systole and
isovolumic diastole were negligible compared with right
ventricular pressure, it should be possible to derive right
ventricular dP/dt from the Doppler-derived VA pressure
gradient curve . In the present study, we performed simultaneous examinations of continuous wave Doppler echocardiography and catheterization . We validated the accuracy of
Doppler-derived right ventricular peak positive and negative
dP/dt and investigated the impact of right atrial pressure on
the Doppler measurements .
0735.1097Nels7.00
IACC V.I. 23. No. 7
June 1994:1638-43
IMANISHI ET AL .
DOPPLER ESTIMATION OF RIGHT VENTRICULAR dP/tit
1639
Methods
Patients. We studied 18 consecutive patients with tricuspid regurgitation who had been referred to our cardiac
catheterization team. The diagnosis of tricuspid regurgitation was established by routine echocardiographic examination . All patients underwent continuous wave and color
Doppler echocardiography during cardiac catheterization .
We excluded seven patients because of inadequate Doppler
examination in the catheterization laboratory . As a result,
the final study group included I I patients (three men, eight
women ; mean age 49 years, range 30 to 69 ; five with sinus
rhythm, six with atrial fibrillation) . The severity of tricuspid
regurgitation was graded by color Doppler echocardiography
as mild in four patients, moderate in five and severe in two
(10). Five patients had mitral stenosis ; five had atria) septal
defect ; and one had dilated cardiomyepathy . No patient had
clinically overt right ventricular failure . Informed consent
was obtained from all patients .
Cardiac eatheterization. High fidelity right ventricular
pressure was obtained with a 7F balloon-tipped fiberoptic
catheter (model 140-7, Camino Laboratories) calibrated electronically and inserted from the right femoral vein. A fluidfilled lumen of the catheter was connected to a standard
fluid-filled manometer system (1295C . Hewlett-Packard) positioned at the midchest level to check baseline pressure
before and after the study. There was either no or minimal
drift over the course of the study . Pressures were recorded
on a multichannel strip chart recorder (Nihon Kohden
Surgical Monitoring System) at a paper speed of 100 mm/s .
The maximal positive and negative dP/dt values were obtained by electronic differentiation of the right ventricular
pressure pulse . High right atrial pressure was expected to
affect the calculation of Doppler-derived dP/dt, which should
be mitigated by high right ventricular pressure (or high
systolic pulmonary artery pressure) . Therefore, right atrial
and pulmonary artery pressures were also measured just
before the Doppler study, and mean right atria). right atrial
v wave and systolic pulmonary artery pressures were obtained as averages of 3 consecutive bents in sinus rhythm
and 6 consecutive beats in atria) fibrillation .
Doppler examination . Continuous wave and color Doppler examinations were performed with a commercially available ultrasound system (model EUB565, Hitachi) equipped
with a 2 .5-MHz transducer in a cardiac catheterization
room . Each patient was examined while in a supine position .
Doppler windows used were apical longaxis and fourchamber views . The continuous wave Doppler beam was
oriented parallel to the direction of the tricuspid regurgitant
jet with the aid of color Doppler echocardiography . Then,
minor manipulalio:.0 of the transducer were performed to
obtain the highest jet velocity. Continuous wave Doppler
recordings were done on a ship chart recorder equipped with
an ultrasound system at a paper speed of 100 mm/s (Fig. 1) .
Pressure and Doppler recordings were begun simultaneously
with a marker on the electrocardiographic tracing to enable
Simultaneous recordings of tricuspid regurgitation velocity curve obtained by continuous wave Doppler echocardiography
and high Ldelity right ventricular pressure (RVP) curve. ECG =
electrocardiogram .
Figure 1.
comparison of data from the same beat. In five patients with
sinus rhythm, hemodynamic conditions were altered by
applying the Valsalva maneuver, and 2 beats were obtained
from each condition . In six patients with atrial fibrillation,
5 beats were obtained from each . As a result, a total of
40 beats of simultaneous catheterzation and Doppler measurements were analyzed.
The continuous wave Doppler-derived tricuspid regurgitant velocity profile was traced manually from the onset of
the QRS complex until the zero crossover point of the
velocity and digitized at 2-ms intervals with customized
computer software . The instantaneous right VA pressure
gradient was reconstructed throughout systole and isovotumic diastole from the simplified Bernoulli equation . The
maximal positive and negative amplitudes of dP/dt were then
determined by differentiating this reconstructed pressure
curve .
Statistical analysis . Data are expressed as mean values s
SD. Linear regression analysis was used to compare maximat values of catheterization- and Doppler-derived dP/dt .
The error in the estimation (A = [Catheter-derived dP/tit] [Doppler-derived dP/dt]) was studied for bias and scatter by
analysis of agreement (Il). Moreover, the proportional error
between Doppler- and catheter-derived dP/dt (A/[Catheterderived dP/dt)) was correlated with mean right aerial pressure and right atria) v wave pressure by using linear regression in 35 beats where the Valsalva maneuver was not
applied (6) . The level of statistical significance was defined at
p < 0 .01 .
Results
Pressure data. Mean right atria) pressure was 4
3 mm Hg (range 1 to Il), and mean right atria) v wave
pressure was 8 ± 6 mm Hg (range 2 to 22) . Three patients
showed high v wave pressure (a10 mm Hg), and 12 beats
IMANISHI ET AL.
DOPPLER ESTIMATION OF RIGHT VENTRICULAR dP/dt
1640
(mmHg/set)
soo
app ® high RAP without PH
A high RAP with PH
Tro
sm
% error of Doppler-derived max(+)dP/dt
.o
6m
400
3m
zoo
Imo
0-1 .0x-15 .4
.0.98
n.40
poO.001
A .-Hone mmHg/sae
100 200 too %a 600 600 7110 600 008
(mmHg/see)
max(+)dP/dt by Bath
100
80 r.0 .13
p.ns
60 A.-236 6b
40
0
20
0
v
5-20
-40
-60
-80
-1000
5
10 15 20 25 30
RA v pressure (mmHg)
Figure 3. Proportional error (A) in Doppler-derived peak positive
[nau(+)] dP/dt plotted against right a!rial v wave (PA v) pressure.
Closed c?rele6 denote a patient with high right atria) v wave pressure
and pulmonary hypertension.
(mmHg/sec)
200
c
u
JACC Vol . 23, No. 7
Junc 1994 :1638-43
am
0
°0
es
o
a
v
E
1m
mean+250
mean-25D
00
-200
Q high RAP without PH
A high RAP with PH
-3101,
loo
200
am
4611 No
am
Tao
(Doppler+lath)/2
em 91111)
(mmH5($Oe)
Figure 2 . Top, Comparison of peak positive [max(+)) dp/m derived
by Doppler with that derived by cathelerization (cash) . A = (catheter,
derived dP/d) - (Doppler-derived dP/dl) . BoUm. Plot of the aver.
age mean value [(Doppler + cathy2] versus the difference [max(+)
dP/dt(Doppler - cath)] between Doppler- and cathelerderived peak
positive dP/d t . PH = pulmonary hypertension; RAP = right atria) v
wave pressure.
were obtained . Mean systolic right ventricular pressure was
52 t 23 mm Hg (range 30 to 100), and mean systolic
pulmonary arterial pressure was 49 ± 23 mm Hg (range 31 to
98). There were four patients with pulmonary hypertension
(systolic pulmonary pressure ?50 mm Hg), and 11 beats
were obtained. One patient had high right atria) v wave
pressure and concomitant pulmonary hypertension, and five
beats were obtained .
Comparison of catheter- and Doppler-derived dP/dt .
Mean peak positive catheter-derived dP/dt was 422 ±
165 mm Hg/s (range 200 to 784) and mean peak positive
Doppler-derived dP/dt was 416 t 173 mm Hg/s (range 190 to
800) . Good correlation was seen for the entire patient group
between measurements, irrespective of the presence of
patients with high right atrial pressure or pulmonary hypertension (y=1 .Ox-15 .4,r=0 .98,N=40,p<0 .001,A=
-5 t 36 mm Hg/s) (Fig. 2). There was neither systematic
underestimation nor overestimation at any mean right atria)
pressure (r = 0. 16, p = NS) or right atria) v wave pressure
(r = 0.13, p = NS) (Fig . 3) . Mean peak negative catheter
derived dP/dt was -394 ± 168 mm Hg/s (range -190 to
-800) and mean peak negative Doppler-derived dFlilt was
-417 ± 166 mm Hills (range -160 to -736) . Good co,relation was also seen for the entire patient group between
catheter- and Doppler-derived measurements (y = 0.9x +
58 .2, r = 0.93, N = 40, p < 0.001, A = -23 t 64 mm Hg(s)
(Fig. 4) . However, in cases with high right atria] v wave
pressure, Doppler-derived peak negative dP/dt tended to
show smaller values than catheter-derived peak negative
dP/dt . The proportional magnitude of this error did not
correlate with mean right atria) pressure (r = 0.17, p = NS)
but did correlate with right atria) v wave pressure (r = 0 .52,
p < 0 .01) (Fig. 5). This tendency was lessened by the
presence of pulmonary hypertension (Fig . 4 and 5) .
Diseossioi)
Determlna(ba of Doppler-derived peak right ve Iricular
dP/dt. Some studies have demonstrated that left ventricular
dP/dt could be obtained from Doppler-derived mitral regurgitant velocity (4-6) . However, there have been few related
studies on Doppler-derived right ventricular dP/dt (7).
Anconina et al . (7) measured the mean rate of right VA
pressure gradient increase from 0 mm Hg (0 m/s) to
16 mm Hg (2 m/s) or from I mm Hg (0.5 m/s) to 16 mm Hg
(2 m/s) and showed good correlation with invasively determined maximal dP/dt . However, the mean rate of pressure
increase may underestimate the invasive maximal dPldt,
especially when right ventricular pressure is high (4,5). In
the present study, we calculated not mean pressure increase
but maximal and minimal values of the right VA pressure
gradient dPldt and compared them with simultaneous catheterderived measurements . We found good correlation between
Doppler- and catheter-derived measurements irrespective of
the level of right ventricular pressure.
Effect of right atrial pressure on Doppler-determined
dPldt. Left ventricular pressure was estimated from mitral
regargitant velocity, and dP/dt was calculated with the
tACC Vol . 23. No . 7
June 1994:1 63 8-43
nOPPI.FR
IMANISHI ET AL .
ESTIMATION OF RIGHT VENTRICULAR dPldr
% error
of
1641
Doppler-derived max(-)dP/dt
100'
80
60
40
20
0
y-0 .5on59 .2
e-0 .93
n.40
p00 .001
n .-23364 mmH •/so
0 100
300 500 400 500 600 700 800 900
max(-)dP/dt by cash (- '" H9/
Figure
5 . Proportional error (5) in Doppler-derived maximal negative [mast - )I dPidt plotted against right atrial v wave (RA v)
pressure. Closed decks denote a patient with high atria) v wave
pressure and pulmonary hypertension .
because in pulmonary
hypertension, right atria) pressure and fluctuation are relatively minor compared with the corresponding right ventricular pressure changes, aad the effects of a rapid increase
in right atria) v wale pressure during isovolumic diastole
should he lessened (Fig . 6).
Study limitations, For measurements of VA pressure
gradients and, thereby. dP/dt to be accurate, tricuspid regur.
-citation must produce a signal of sufficient amplitude to be
quantifiable throughout systole and isovolumic diastole,
which may he difficult in patients with only trace tricuspid
regurgitation. Use of contrast agents to enhance the trace
signal might partly solve this problem (12,13) . In the present
study . Doppler recordings were done in patients in a supine
position in a catheterization laboratory, which may be one
reason for the relatively low rate (I 1 of 18 patients) of finding
analyzable tricuspid regurgitant flow velocity .
In the presence of tricuspid regurgitation, the validity of
isovolumir. indexes as an indicator of contractility and relaxation is questionable. Various studies have demonstrated
little effect of mitral regurgitation on the accuracy of left
ventricular dP/dt determination (4-6). However, to our
knowledge, no studies have clarified the effect of tricuspid
regurgitation an the accuracy of right ventricular dP/dt
determination, but on the basis of the effect of mitral
regurgitation on left ventricular dP/dt, we consider that the
effect might be minimal. Still, right ventricular dPldt derived
from tricuspid regurgitant velocity should be a good index of
directional changes in contractility and relaxation . Other
studies of the effect of tricuspid regurgitation on the accuracy of right ventricular dPldt determinations will be required.
Although a variety of indexes of ventricular function have
been proposed, most including dP/dt, are influenced by
alterations in loading conditions (14) . Nevertheless, because
left ventricular dP/dt has been used for assessment of
ventricular function clinically, it is reasonable to determine
to the catheter-derived value, perhaps
Figure 4. Top, Comparison of peak negative [max(-)l dP!dt derived
by Doppler with that derived by catheterizntion (oath) . ,h = (catheterderived dP/dt) - (Doppler-derived dP/dt). Bottom, Plot of the average mean value [(Doppler + cathy21 versus the difference bnux( - )
dPldt(Doppler - call)] between Doppler- and catheter-derived peak
negative dP/dt. Other abbreviations as in Figure 2 .
assumption that left atrial pressure was negligible compared
with left ventricular pressure . It is problematic, however,
whether right atrial pressure can be negligible in calculations
of right ventricular dP/dt because right ventricular pressure
is relatively lower than left ventricular pressure . We have
shown that the Doppler method can accurately estimate
peak positive dP/dt irrespective of the [eve ; of right atria]
pressure . However, Doppler-derived maximal negative
dP/dt is affected by right atrial pressure and shows slightly
lower values than catheter-derived measurements in patients
with high right atria) v wave pressure without pulmonary
hypertension . This underestimation by the Doppler method
could be explained by a rapid decrease in the right VA
pressure gradient during isovolumic diastole as a result of a
rapid pressure increase in the right atria) v wave (Fig . 6) . The
possibility of this error should be home in mind when right
ventricular maximal negative dPldt is estimated with the
Doppler method. However, even in patients with high right
atrial pressure, when pulmonary hypertension was present,
the Doppler-derived peak negative dP/dt could be identical
1642
IMANISHI ET AL.
DOPPLER ESTIMATION OF RIGHT VFNTPICULAR
JACC vd . n. No. 7
lure 1994: 1638-43
dP/dr
+-ECG- -
-s--dp/dt --v
(RV-RA)
Fgare 6 . Examples of right ventricular
pressure (RVP) and veotriculoatriat
(VA) pressure gradient (PG) curves . Left
panel, Curves from a patient with normal
right atria) pressure (RAP) (right atria)
v wave pressure 5 mm He) without pulmonary hypertension. Both curves are
nearly identical. Right panel. Curves
from a patient with high night atria) pressure (right atriat v wave pressure
13 man Hg) without pulmonary hypertension . Note a rapid deceleration in right
VA pressure gradient curve compared
with right ventricular pressure curve
(RV - RA) . ECG = electrocardiogram .
n
PG
similar indexes for the right ventricle . It has been reported
that the normal maximal value of catheter-derived right
ventricular dP/dt is 437 ± 116 mm Hg/s (15). The present
study shows the value of Doppler echocardiography in
assessing right ventricular dP/dt. Other studies are needed to
determine load-independent indexes of right ventricular
function . Our study will show the way to obtain noninvasively other dP/dt-related indexes that are relatively insensitive to loading conditions, such as dP/dt corrected by
end-diastolic volume or by isovolumic pressure (14).
Clinical implkatlmd. To date, investigations concerning
right ventricular function have been infrequent (16,17), possibly because the right ventricle is perceived to be less
important (18), or because its geometric complexity has
made volume determination difficult (19-21) . However, to
understand cardiac performance, information on right ventricular function is needed as well as left ventricular func.
tion . For example, in dilated cardiomyopathy, right ventricular function plays an important role in determining exercise
capacity, and its measurement has been shown to have
significant prognostic value (22) . Right ventricular function
is related to long-term survival in patients with chronic
congestive heart failure secondary to ischemic heart disease
(23). Also, evaluation of right ventricular performance would
be helpful in determining treatment for right ventricular
infarction or pulmonary hypertension .
Our study demonstrated that right ventricular dP/dt could
be estimated accurately and noninvasively by a continuous
wave Doppler method . The major advantage of this new
Doppler method is that it provides a noninvasive estimation
of right ventricular dP/dt on a beat-by-beat basis, which
should make it ideal for serial measurements in patients with
tricuspid regurgitation. Because tricuspid regurgitation is
common in patients with a variety of cardiac diseases, a
method for approximating right ventricular dB'dt on the
basis of Doppler-derived tricuspid regurgitation should be
widely applicable .
Cosehsaluu. Maximal right ventricularpositive dP/dt can
be estimated accurately and noninvasively by a continuous
wave Doppler method. However, when right atria) pressure
is significant compared with the corresponding right ventricular pressure during isovolumic diastole, the Doppler
method might underestimate the peak negative dPldt measured at catheter nation .
We thank lanes D . Thww, MD, FACC, Director . Cardio sedw laugiog.
The Clevelnld Clinic Faondaiw, for his wvahuble comments an this work .
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