Download A Method for Determining Left Ventricular Mass in Man

A Method for Determining Left Ventricular
Mass in Man
By CHARLES E. RACKLEY, M.D., HAROLD T. DODGE, M.D.,
YANK D. COBLE, JB., M.D.,
AND
V ARIOUS methods have been devised by
others for estimating the weight of the
normal heart in man by relating heart wveight
to body size and age.'1-3 In other studies the
weight of the left ventricle has been compared
to total heart weight in postmortem hearts.'
ROBERT E. HAY, M.D.
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clamping the aorta just above the aortic valvxes.
The hearts were suspended over a Schonanderbiplane anlgiocardiogr-aphic unit so that the heart
position and distances with respect to films and
x-ray tubes simulated those present during angiocardiography in vivo when films are taken in the
anteroposterior (a-p) and left lateral projections.
Barium sulfate paste was injected into the left
ventricular chamber to an initial known volume
of 80 m]., followed by added known increments
of 20 to 2.5 ml., until contrast material leaked at
the mitracl xvalve, or the left ventricle ruptured.
Biplane films were taken at each known volume
over anl 80- to 300-ml. volume ranige, as indicated
in figuire 1.
On each film the image of the left ventricuilar
chamber was traced, the enclosed area (A) was
determined by planimetry, and the long axis (1)
of the ventricular chamber was directlv measured.
It was assu-med that the left ventricuiar chamber
could be represented by anl ellipsoid reference
figure. The transverse diameters (d) were caleulated from the a-p and lateral films bv use of the
4A
formula for th:e area of aii ellipse: d
. Each
of the axes AA7cas corrected for distortion due to
inonparallel x-ravs from knowledge of x-ray tubeto-film distances and left ventricle-to-film distanices. This method for correctinig for x-ray distortioII has been described previously.7
Left veentricular chamber volumes were cale-i
lated by uise of the formula for the xvolume of an
ellipsoid as described earlier:7
4 d~1 di
I
^3 7r92 X2-2
wlhere d11 = transverse diameter calcullated from
the a-p film; d1 = trainsver-se diameter calculated
from the lateral film; 1 = maximum measured
chamber length whether on the a-p or lateral film.
The calculated volumes wvere corrected by a regression equationi obtained from previous studies:
.' -0.928J 3.8 ml.* where V' is the adjusted
volume and V7 is the xvolume calculated by the
previous equation.
On each a-p film the outer margin of the free
left ventricular wvall was outlined, as illustrated in
figure 2. A 4-cm. segment of the free left ventr-ictiular xa.111 at approximately the junction of the
Smith's method for estimating the normal left
ventricular mass has been utilized by Bing for
determining left ventricular efficiency.4 Friedman, in radiographic studies of heart volume,
demonstrated a relationship between the total
heart v olume, myocardial volume, and tIme
volume of the heart chambers.5 Furtlhermore.
he demonstrated that the relation betw7eenit
these volumes differed in patients with different types of heart disease, but he did nlot
attempt to relate the volume or mutlscle imlass
of individual cardiac chambers to the total
heart volume. Amundsen, in extensive stud-ies
of total heart volume, has discussed the clifficulty in detecting dilatation and hypertrophy
of individual cardiac chambers from conventional x-ray films of the heart.; Th-e prese nt
study is concerned with the development and
clinical application of a method for dete-rti.nring left ventricular mass iin mail.
Methods
Twenty-three postmortem human hearts wvere
prepared by suturing together the leaflets of the
mitral valve, inserting a large-bore needle into the
ventricular cavity through the aortic valves, and
From the Medical Service of the Veterans Aclministration Hospital, and the Department of Medicine,
University of Washington School of Medicine, Seattle,
Washington.
Supported in part by Grant H-3391-C5, U. S. Pulhlie Health Service, and by the Washington State
Heart Association.
Presented in part before the 35th Scientific Sessions,
American Heart Association, Cleveland, Ohio, October 26-28, 1962.
6366
(ir(iilaltion, Voliume
XXIX, May 1964
LEFT VENTRICU5LAR MASS
66f7
of the left ventr-icular chamber plus mtusele wall
was dletermined by the following formuila:
4r
i+hx'±j[hh
v 240
wvhere V\ e+w equals volu.me of the left ventricular.
clhamber. plus x\vall, hI equals wall thickness, and
dL d1, and 1 are axes as defined in the pr-eviouis
> 200
0
(quatv)11s.
Left ventrictilar mass \vas calculated as follows:
Left venitricuIl.ar inass eq(utals (V,. + s. Vt) 1.050,
wx here V,-, and V' are ovlimes as pr-eviouisly defiiiel. The xvaltie 1 .050 is the specific gravity of
9160
0
C
120
00
80
~ ~ ~0
000
000
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40
0
40
80
120
160
200
KNOWN VOLUME - CC
240
280
Figure 1
Calciiulateda left ventrictular chanhber toluinmesv of htman2ai
p)o.stmortenm,t lhearts are related
to
kniiott volunmes.
apical aiid middle third xvas selected, sinice this
regioni is most clearly outlined on clinical angiocatrdiogrims. Care xw as taken to avoid iicludinig
a papillary muscle in this segmeiit. The area of
the selected segment was determined by plainimetry anid the average wvall thickness xw as obtained from the quotient of the segmenit area
divided by the segmenit len-gth. An in-tegrated vall
thickniess was used, since the irregular margins of
the trabeculae result in a varying wall. thickness
over aniiy given segment of xvall.
The wall thickniess was corrected for distortionl
from nonpariallel x-rays as follovs. The distance
of the portioni of the left venitricuilar xvall selected
for the measurement of thickniess to the plane of
the cenltral x-ray beamn, as identified by a lead
marker, was directly measiuired on} each a-p film.
On the lateral film it was asstumed that this portiomi of the left ventriculair wxall wvas at approximately the level of the center of the opacified left
ventricle. The distaince of the ecenter of the opacifled left venitriele to the planie of the cenitral x-raxbeam, as inidicated by a lead marker, was measured on the lateral film. These measurements fr-om
the a-p anid lateral films anid the known x-ray
tu-be-to-film distances were used to ctllculate the
correction factors, which were applied to correct
wall thickness for distortion due to nonparallel
x-rav beams, as previously desciribed.7
The corrected wall thickness wvas added to each
semi-diameter that wxas used for calculating the
left ventricular clhamber voliinme, and the volume
(;
X,M/
ur/-iil{a/'(jua, Volume \XIX
196-i
heart miiusele .a.s determined in stuidies by Bar(leeIl.s .This saime valuic for specific gravitv for
hear t musele xas oI)tained for- onie heart in the
present studyix
TIhle left x entr-ictilartimass as defined in this
.stlm(l is mepresemnted Ib th-ie weighlt of the free
wall of the lekt ventricle an( the interventricularsepttiuIm. TIhle acttimal \veiglit of the postmortem left
venitricle was deter-minied after r-emovinig the free
right venitricuilair wall, the atria, the aortic land
mitral valves, trabeculae from the right venitricui-
Figure 2
An anteroposterior film. of a hlunman postmoritem heart
(liste?(ldecl with contrast nmaterial. A segment of the
free tva/llused for deterumining mcaill thickne.ss is illustrated.
RACKLEY ET AL.
668
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lar side of the interventricular septum, and the
epicardial fat.
In six subjects left ventricular mass as calculated from angiocardiograms, which. were performed 1 to 15 months prior to death, was compared wxith left ventricular wveiglht determinied at
postmortem examination. 'The method used. for
calculating left ventricular mass wx as the same as
that described for the postmortem hearts. The
time of film exposure within the heart eyvcle wxas
recorded as described elsewhere.9 Films recorded
near end-diastole were used to calculate ventricular mass because the lateral xw all thickness is more
clearly defined on films taken during the late
diastolic phase of the heart cycle. Films taken
during ventricular systole often showv coonsiderable
irregularity of the inner wall of the ventricle, and
prominent papillary muscles that project into the
ven-tricular chamber make the wvall thickness difficult to define and measure clearly.
Results
There were 97 individual determinations of
left ventricular chamber volume and mass on
23 postmortem hearts. Measurement of left
ventricular mass by this method is dependent
upon calculation of chamber volume and the
volume of the chamber plus the ventricular
wall. In figure 1, calculated left ventriculai
chamber volume is related to the known volume of contrast material injected in.to the
500.
Y
=
0.99X- 11
S.E.E.= 23 GM
E
a
-
400/
0 300
,200
100
0
100
200
300
ACTUAL WEIGHT
-
400
500
grams
Figure 3
The 97 determinations of left ventricular
23 postmortem hearts are camnpared to
rmass values.
mass
thte
in the,
knozwn
E
Ea
4001
-I-
I
0
ILl
a
gz
U
U
ACTUAL WEIGHT
- grams
Figure 4
A .o7i"rsioi of postmortem left ventricular weights
and v attes for left ventriculatlr weight calculated during life inix stxuibiects.
chamber over a range of 80 to 300 ml. The
regrerssion equation that expresses the relation
betweein the known and calculated volumes
and the standard error of estimate (15 ml.) is
shown in the figure.
T:he relation between the 97 calculated left
ventricular mass values and the measured left
ventrictular weights is illustrated in figure 3.
The left ventr-icular mass was calculated at
each charnber- volume so that there were one
to niine individual calculations of mass on the
23 postmortem hearts. In figure 3, each calculated mass value is indicated by a horizontal
line and the individual values for each ventriele are connected with a vertical line. The
mneasured left ventricular weights were 121 to
453 Gm. The regression equation that related
the measuired and calculated values and the
standard error of estimate (23 Gm.) is shown
in figure 3.
Figure 4 contains a comparison of the postmortern left ventricular weight and left ventricular mticass as calculated from angiocardiograin.s performed during life in the six subjects. Figure 5 demonstrates an in vivo angiocardiogranm with the calculated values for
chamrlbei volume, wall thickness, and mass.
The se-gmii(ent of the free left ventrictular wall
X YJ
L.XIAL,v 1904
I.01-tll"
I:
669
LEFT VENTRICULAR MASS
gramrs of the riglt hleart anid from postmortem
examiniationi of the heart.
Discussion
L.V. VOL.
262
c.c.::`
~~1.07cer.
t
LLVMASS
34
Qm7
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Figure 5
Atn aniter.op)o.stei.rior
filInt
of
the
opacified
left
ventriel
of the subjects in figulre. 4.
The chamiber volumnte, wcall thickness, portion of thei
ventricueilar twall used to detertnine twall thickness, and
calculated left venitricultar ?tnass ar.e illtustratedl. Cactluterts are positioned in the publntionoairzi aritery, left atri
at endd-iastole front
uti,
and
one
left ventr'icl(e.
that was uised for the determninationi of wall
thickness is ouitlined. Filmns taken duirinig the
end-diastolic portioni of the hleart eyele weTre
tised for the calculatioins of ventricular mass
as described. There xvere three to six calculated mass valtues oIn each subject as indicated by the horizontal lines in figure 4. The
observations in each subject are coninected
by a vertical line. The averages of the individual calculated values for mass in each
subject are indicated by the longer horizonital
lines. As shown in figure 4, the caleulated anid
measuired values for ventricuilar mass agreed
closely, except in one subject. This subject
had pulmonary vaseular disease, marked puilmonary hypertension, and right ventr.icuilar
dilatation and hypertrophy. The erroneously
large calculated ventricuilar mass values were
due to an enlarged right ventricle that projected to the left, beyond the free mnargin of
the left ventricle, and resuilted in the appearance of an erroneouisly thick free wall of the
left ventricle on the anteroposterior x-rayv films
(fig. 6). This was e,vident from anglioardli)Ciri.jel,illon. Volyime XXIX, illal. 19(...
.Il the inethccl descrile(l here, for (leterininig left xventricular chamber volume and
nass, it is assumed that the left ventricular
chamiber and chambler pluis wall cai 1)e represeintel(1 by aii ellipsoid reference figuire.
Furthermore, it is assumned that the chamber
volumew, cai-n be' caleulated from the projection.s of the ventricuilar chamber on l)iplane
films after correction for distortionl (Ilue to
nionipara.llel] \-Iavs, l)nbt witlhotot correctioni for
di.stor-tion1 duce to r'otationl or positioni of the
chamb1er. hTese assuminptions were tested in
earlier studies of methods for determiniing the
vxl-oh e of the left ventrictular chamber of
postmiiortem lhearts. In these earlier studies,
left ventrictilar cliamber volumes caleulated
by the method used in this sttudy were coinpared to kniown voltumes anid volumes calctilated l)v mi-ore tedious metlhods, wxhich perm1it correctiol for distortion duie to ventricuilar
rotation or position.7 Voluimes caleulated by
these aiainois methods were similar. The comparison of knjown volumes aind caleulated voltmes ini the piresecit study demonstrated a
.1
Figure 6
Anteroposterior filin of the opacified left ventricle in
the sil)jeCt wvith marked riglht ventrcuilar enlargement.
f'lure i.s the erroneotus appearance of atn increaised
thickness of the lateral left vetntricular wall.
670
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somewhat higher standard error of estimate
than was observed for this method for calculating volume in the earlier study.
To calculate left ventricular mass by the
method described here, it is necessary to
determine a left ventricular wall thickness
that is representative or has a relatively constant relation to the thickness of the ventricle
as a whole. A segment of the free left ventricutlar wall as visualized on the anteroposterior
film was selected, because this is the portion
of the ventricular wall that is most often
clearly seen and can be measured on angiocardiograms. There is evidence fromi postmortem studies by others that there is a
relatively fixed and close relation between
the thickness of the lateral left ventricular
wall and interventricular septum.1" 1' The
results of this study demonstrate a close relation between thickness of the lateral left ventricular wall, dimensions of the left ventriculaichamber, and the left ventricular mass.
Left ventricular mass as determined in this
study included the free wall of the left ventricle and the entire thickness of the interventricular septum. Others have dissected the
septum into a right and left ventricuilar portion prior to weighing the left ventricle.'4
However, as discussed by others, an accurate
division of the septum into right and left
ventricular portions is very difficult, if not
impossible,10-12, 15 and was not attempted in
this study. The method used for dissecting and
determining left ventricular weight in this
study is similar to that used by others. 12
The method described here for determining
left ventricular mass can only be applied
when a segment of left ventricular wall is
clearly visible and is representative of the
over-all thickness of the left ventricle. Pericardial effusion or thickening would be, expected to give the appearance of an abnormally thickened left ventricular wall and invalidate the method. An erroneously thickappearing left ventricular wall was also
demonstrated to be the case in the angiocardiograms from the subject with marked
right ventricular hypertrophy in this study. In
addition, this method cannot be applied to pa-
RACKLEY ET AL.
tients in whom the left heart border is obscured by a pleural effusion, a pulmonary
lesion, or by the lateral rib cage, as is not
uncommon in recumbent patients with greatly
enlarged hearts. Finally, in patients with a
venatricular aneurysm involving the free wall
of the left ventricle and in patients with asymmnetric left venitricutlar hypertrophy, as has
been described in some subjects with subaortic hypertrophic aortic stenosis,'" the freewall thickness would very likely not be representative of the thickness of the remainder
of the left ventricle. In such patients, this
method would not be expected to give a reliable estimation of left ventricular mass.
Summary
A method for determining left ventricular
mass by the use of biplane angiocardiography
is described. This method was tested on 23
postmortem human hearts with left ventricular
weights of 121 to 453 Gm. The left ventricular
chambers of these hearts were distended with
known volumes of contrast material and biplane x-rays were recorded over an 80- to 300ml. range of volumes. Values for left ventricular mass were calculated from the biplane
x-ray films and were demonstrated to agree
closely with directly measured left ventricular
weights. Th-e standard error of estimate was
23 Gm. In six patients, left ventricular weights
were calculated from angiocardiograms performed during life and compared with postmortem left ventricular weights. There was
close agreement between the calculated and
measured values for ventricular weight in all
but one subject. This subject had marked
right ventricular hypertrophy which resulted
in an erroneously large calculated value of
left ventricular mass.
References
1. SMITH, H. L.: The relation of the weight of the
heart to the weight of the body and the weight
of the heart to age. Am. Heart J. 4: 79, 1928.
2. ROSAHN, P. D.: The weight of the normal heart
in adult males. Yale J. Biol. & Med. 14: 209,
1941.
3. ZEEK, P. M.: Heart weight: I. The weight of the
normal hulman heart. Arch. Path. 34: 820,
1942.
(irt 'laliohn, Voluine XXIX, AIav 196.;
671
LEFT VENTRICULAR MASS
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4. BING, R. J., HAMMOND, M. M., HANDELSMAN,
J. C., POWERS, S. R., SPENCER, F. C., ECKENHOFF, J. E., GOODALE, W. T., HAFKENSCHIEL,
J. H., AND KETY, S. S.: The measurement of
coronary blood flow, oxygen consumption, and
efficiency of the left ventricle in man. Am.
Heart J. 38: 1, 1949.
5. FRIEDMAN, C. E.: Heart volume, myocardial
volume and total capacity of the heart cavities
in certain chronic heart diseases. Acta med.
scandinav. Suppl. 140: 257, 1951.
6. AMUNDSEN, P.: The diagnostic value of conventional radiological examination of the heart in
adults. Acta radiol., Suppl., 181, 1959.
7. DODGE, H. T., SANDLER, H., BALLEW, D. W., AND
LoRD, J. D., JR.: The use of biplane angiocardiography for the measurement of left ventricular volume in man. Am. Heart J. 60: 762,
1960.
8. BARDEEN, C. R.: Determination of the size of
the heart by means of the x-rays. Am. J. Anat.
23: 423, 1918.
9. DODGE, H. T., HAY, R. E., AND SANDLER, H.:
An angiocardiographic method for directly
determining left ventricular stroke volume in
man. Circulation Research 11: 739, 1962.
10. REINER, L., MAZZOLENI, A., RODRIGUEZ, F. L.,
AND FREUDENTHAL, R. R.: The weight of the
human heart: I. Normal cases. Arch. Path. 68:
58, 1959.
11. REINER, L., MAZZOLENI, A., RODRIGUEZ, F. L.,
AND FREUDENTHAL, R. R.: The weight of the
human heart: II. Hypertensive cases. Arch.
Path. 71: 180, 1961.
12. GRANT, R. P.: Architectonics of the heart. Am.
Heart J. 46: 405, 1953.
13. JONES, R. L.: The weight of the heart and its
chambers in hypertensive cardiovascular disease with and without failure. Circulation 7:
357, 1953.
14. HERMAN, G. R.,
AND
WILSON, F. N.: Ventricu-
lar hypertrophy: A comparison of electrocardiographic and post-mortem observations.
Heart 9: 91, 1922.
15. DRESCHEL, J.: Zur Architektur der Herzkammerwande. Ztschr. Anat. 87: 29, 1928.
16. MENGES, H., JR., BRADENBURG, R. 0., AND
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The Observational Method in Clinical Medicine
In order that observation should have its proper value certain principles must
be thoroughly familiar. The true nature of the method must be understood, its
special liabilities to fallacy must be known, and its weakness of trusting to
intuition when actual proof is possible, overcome. There can be little doubt that
it is this last-named characteristic of ordinary clinical practice that inclines the
critics of the observational method in medicine to view it with so little charity
or hope. In clinical work proof is usually difficult to obtain, often tedious and
unencouraging to aittempt, and not rarely altogether impossible; at the same
time any effort towards it is constantly overshadowed by the urgency to act.
It is natural, therefore, for the expert clinician to rely on his intuition and
judgement even when actual and final proof is possible, though this preference
does constitute a reproach to the method from any scientific point of view. If
clinical observation is to renew lits prestige and to continue its indispensable
function of stimulating the experimental attack on medical problems, it can
do so by showing resolution in looking for proof wherever proof is possible,
and a scientific standard in its scrutiny of evidence.-The Collected Papers of Wilfred Trotter, F.R.S. London, Oxford University Press, 1946, p. 124.
Circulaion, Volume XXIX, May 1964
A Method for Determining Left Ventricular Mass in Man
CHARLES E. RACKLEY, HAROLD T. DODGE, YANK D. COBLE, JR. and
ROBERT E. HAY
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Circulation. 1964;29:666-671
doi: 10.1161/01.CIR.29.5.666
Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231
Copyright © 1964 American Heart Association, Inc. All rights reserved.
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