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Intracardiac ultrasound determination of left ventricular volumes: In vitro and in vivo validation
JACC Vol. 24, No. I hly
247
8994:24-F53
are superior because the
~~gi~gra~~~c (7) and tanta ec~~card~~gra~~~c methdards have validated transt ods of ca~c~~ati~gleft ventricular volumes and ejection availak imthe left ventricle. From the Division of Cardiology and Department of Medicine, Hartford spital, University of Connecticut, Hartford, Connecticut. This study was sented in part at the 4lst Annual Scientific Session of the American College of Cardiology, Dallas, Texas, April 1992. This study was supported by a grant Foundation, Hartford, Connecticut. fro 1993; revised manuscript received February 994. 1, Dr. Linda D. Gillam, Director of Echocardiography, Cardiac Laboratory, Hartford Hospital, 80 Seymour Street, Haltford, Connecticut 06115. 01994 by the American
College of Cardiology
ventricle (14). Ah
248
FISHER ET AL. INTRACARDIAC
ULTRASOUND.DERIVED
LEFT V~~TR~CULA~
VOLUMES
JACC Vol. 24, No. 1 July 1 :247-53
may be obtained in smaller animal he tained using transthoracic parasternal analogous to thos re therefore edgily suited to volume short-axis views a determinations using Simpson rule algorith of this study, therefore, intracardiac ultrasound volumes with Simpson
I
mm. The catheters
nation of the ~lt~so~nd
ts of the left ventricle were und, and their volume was acement method. . In vivo studies were anesthetized, intubated pigs (weight 14 to were premeditated with tiletamine byd
was always included as the first slice in the reconstructed volume. es calculatedfrom the intracar-
using least-squares lin pressure monitoringand arterial bl sampling. Ventilatory settings were adjusted in response to blood gas sampling performed at least every 30 min. Femoral vein access was USedfor the intravenous delivery of fluids and medication, and continuous electrocardiographicmonitoring was established to monitor heart rate and rhythm.
cross-sectional area measurements, images from a single heart recorded at 10 short-axis levels were analyzed in duplicate by each of two different echocardiographers. The
es ragged
e
artifact.
method of Shrout and Fleiss (17)and by the Cronbach alpha estimate of the reliability coefikietat (18). The reliability refers to the pr~po~~o~of the variation of an observation that is due to section to section variability in
sectional images (at
from3 to
250
FISHER ET AL. INTRACARDIAC ULTRASOUND-DERIVED
JACC Vol. 24, No. 1 July 1994:247-53
LEFT VENTRICULAR VOLUMES
Relation between left ve~t~cul~r volumes de!ermined by iac Mlt~sou~d and latex cast v0~l~rn~~ for ammal hearts eration alone. ~~t~s0~~d images recorded at O.S-cm intervals were used.
respectively). In viva, ~e~lo~yna~i~ variables. There was no sign cant change in heart rate and systemic arterial and I ventricular pressures between the intracardiac ultrasound and angiographic studies. Vo/unre determinarions. When all imaged sections were used, intracardiac ~lt~sou~d v end-systole correlated well with phy (Y = I .04X - 3.6, r = 0.91, end.diastolic and end-systolic values were cons rateiy, the relations we 1.04X - 3.5, r = 0.82, S .3 ml, respectively), alth r correspondence with en
tionswere riot si
ejection &action was des 4. Relation between left ventricular volumes determined by intracardiac ultrasound and latex cast volumes for hearts preserved by formalin fixation tier balloon distention. Ultrasound images recorded at O.S-cm intervals were used.
ic volume (cc)
contrast angiographic
volume (co)
fewer cross sections were
larger error
s
The choice ofa
of volume calculation acco tion was based on two
ventricle (23). second, the imaging orientaracardiac ultrasound beam yields images ideuited to Simpson rule reconstruction. Aitb~ug~ from int of view of ease of application it might bc to adapt single or biplane prolate ellipsoid a~goritbms to intracardiac ultrasound use because they require fewer component measurements, both the limited field of view and
of ~a~erest~~at~o~
at this
is study is ea titation and The results suggest that more complex an three~d~m~asioaal ~e~oastr~~tive tee construction are not necessary for ac nations in normal ventricles. In additiofl, a study, the ability of disto~ed venlricular
closely to the latex cast volumes b the angiographic volumes is in transthoracic studies. These differences
are ex
252
FISHER ET AL, MTRACARDIAC ULTRASOUND-DERIVED LEFT VEMlZlCULAR VOLUMES
the intrinsic diiferenccs in the two imaging techniques and the methods ofvohune calculation.First, even with the high resolution images obtained with high frequewcyintracardiac ic techniquesdefine the endocardialdevices, e innermost prominent trabeculae, blood in ad thus the volume within the muscufar ~~fQldin~s is not considered.Furthermore, the contribution of the left ventricular outflow track to total left ve recognizedby the Simpson rule meth
The
error ~nbcre~tin an ccc the fact that because the
c ultrasound tech
papWry muscles and trabeculae. dye (19)and the errors inke 20). Finalty, but extrer~~~y art
basis for the correction factors proposed by Kennedy et aP. (16)and used in this study. However, it might be argued that even with use of the correction factor, angio~~h~c volu
as it is at the skia. Thus
is farther removed fro catheter will track t
This study demonstrated a weaker c intmcardiac ultrasound and an systolc than at end-diastok. Thi of end-systolicvaluesavailab
we of trabecular In
s IS most ~rouounced at factors w also reflected in the COE&between ultrasound and angiographic
because systolic contraction tends to obscure
ecauseintracardiacultrasoundvolumes at end-systslewere generallysmallerthan those nxasurc-d the tendency to underestimate end-systolic volumes is due ~u~~~~~I~, the derivedultrasound ejection fractions to the fact that a catheter that is relativelyimmobile throughtended to overestimate their angiographic counterparts. However,althoughmost of the points were closely clustered, the correlationobtainedwasfair (0.69),and the slope was unity. Although encouraging, these data suggest that if this method is to be used for determinations of ejection fraction in the clinical setting, a normal range of values for this technique should be established, and the validation should be extended to include a wider range of ventricular fu . The ability of intravascularultrasound to provide accurate measurements of crosssectionalareas of arteries has been previously demonstrated I21,22), but the importance of a central coaxial catheter position has been emphasized. A coaxial position is important bxause my deviation from this alignment will result in
out the cardiac cycle will result in a disproportionate weighting of smaller apical volumes into the end-systolic volume determinations. it& the current state of the art of the following limitations of this iermination should be noted. First, vices, the field of view provided by intracardiacultrasound catheters is limited and prevents the recording of a full cross-sectional area in large hearts, icularlyat the mitral valve level. At this time, this woul preclude total volume dete~inat~o~s in most adult human hearts and possibly those of smaller animals with grossly dyskinetic segments. However, ongoing technologic advances should ameliorate this problem by providing lower frequency devices. Jt is expected that the optimal frequency
4. Carr KW. EngPer RL, Forsythe J , Johnson AD, Gosink B. of left ventricuPar ejection fraction by ~e~~a~~c~~ cross-sechd ~~~~o~ra~~y. Circulation 197959: I%-2rJ6. r MB,
s TA, et al. Left ve~t~~~~arvolume fr e~~~ar~iogra~~y. Cir~~~atioo 1979; an CL, Tow DE. and Vo~Mmes by 1999:60:760-6
8, F frac
8.
echo-
, Ports TA, Snider R., iciilldr PI ation of left ventricular volume graphic and a~~io~~a~~~~ comparisons. Circulation
J9~~;62:54~-57.
9.
11.
aendchen RV, Meerbaum S, Corday E. Assess~e~n of Ma~t~tative methods for 2-~~~e~sio~a~ ec~oc~~~o~~a~~y. Am J Cardiol
12.
Fernandez GC, Waggoner Winters icular volumes by two-dime aal echoaccurate approach Cir~~~at~o~ 1983;67:
13
, Daughters GT, et al. Limitations of comparing dimensional ecbo~~diog~~~y, myocardial markers and cinean~io~ra~~y. Am 3 Cardiol B982;50:512-9.
14. Schwartz SL, Gillam LD. Weintraub AR, et al. Bntracardiac echo ography in humans using a small-sized (6F). low frequency (12.5 ethods, imaging p!anes and clinical expertence. ultrasound cathe!er J Am Colt Cardiol 1 ;21:189-96. is. Bentivoglio LG. Griffith LD, Cuesta AJ, Geczy M. Wa ation of formulas for left ventricular volume using canine casts. J Appl Pbysiol 1972;33:365-8. 16. Kennedy JW, Trenholme SE. Kasser IS. Left ventricular volume and mass from single-plane cineangiograms.
ressure-area
linical Experiments.
14.
ique,
if corn
Wiley. 19X62-3. IS. Bernstein IN. Applied Verlag, 1985:390-l.
hfuhivariate
Analysis.
New
York:
New York: Springer-
19. Vas R, Diamond GA, Forrester JS. Whiting JS, Swan HJC. Computer enhancement of direct and venous-injected left ventricular contrast an-
21.
I. Wyatt HL. Heng MK, Meerbaum S, et ai. Cross-sectional echocardiography II. Analysis of mathematic models for quantifying volume of the formalin-ftxed left ventricle. Circulation 1980;61:11 J9-25. 2. Helak JW, Reichek N. Quantitation of human left ventricular mass and volume by two.dimensional echocardiography: in vitro anatomic validaShoukas AA, Weiss JL. Accurate volume ventricle by two204. dimensional echocardiography. Circulation 1979; 4. Weiss JL, Eaton LW, Kallman CH, Maughan WL. Accuracy of volume
22.
23.
aughan WL,
24.
raphic estimation of left ventricular volume. Cathet Cardiovasc Diagn 1995;1:7-12. Nishimura RA, Edwards W . Warnes CA, et al. Intravascular ultrasound imaging: in vitro validation and pathologic correlation. J Am Coil Cardiol 199O;t6:145-54. Nissen SE, Gurley JC, Grines CL, et al. Intravascular ultrasound assessment of lumen size and wall morphology in normal subjects and patients with coronary artery disease. Circulation 1991:84:JO87-99. Chase JS, Brisken AF, Maurer G, Siegel RJ. Geometric accurasy of ng. J Am Sot Echocardiogr 1992;5:577-87. intravascular uhrasoun JS, et al. Human left ventricular pressureFisher JP, McKay RG, area and pressure-volume analysis using echocardiographic autumatic boundary detection [abstract!. Circulation 1992;86 Suppl M-261.
247
8994:24-F53
are superior because the
~~gi~gra~~~c (7) and tanta ec~~card~~gra~~~c methdards have validated transt ods of ca~c~~ati~gleft ventricular volumes and ejection availak imthe left ventricle. From the Division of Cardiology and Department of Medicine, Hartford spital, University of Connecticut, Hartford, Connecticut. This study was sented in part at the 4lst Annual Scientific Session of the American College of Cardiology, Dallas, Texas, April 1992. This study was supported by a grant Foundation, Hartford, Connecticut. fro 1993; revised manuscript received February 994. 1, Dr. Linda D. Gillam, Director of Echocardiography, Cardiac Laboratory, Hartford Hospital, 80 Seymour Street, Haltford, Connecticut 06115. 01994 by the American
College of Cardiology
ventricle (14). Ah
248
FISHER ET AL. INTRACARDIAC
ULTRASOUND.DERIVED
LEFT V~~TR~CULA~
VOLUMES
JACC Vol. 24, No. 1 July 1 :247-53
may be obtained in smaller animal he tained using transthoracic parasternal analogous to thos re therefore edgily suited to volume short-axis views a determinations using Simpson rule algorith of this study, therefore, intracardiac ultrasound volumes with Simpson
I
mm. The catheters
nation of the ~lt~so~nd
ts of the left ventricle were und, and their volume was acement method. . In vivo studies were anesthetized, intubated pigs (weight 14 to were premeditated with tiletamine byd
was always included as the first slice in the reconstructed volume. es calculatedfrom the intracar-
using least-squares lin pressure monitoringand arterial bl sampling. Ventilatory settings were adjusted in response to blood gas sampling performed at least every 30 min. Femoral vein access was USedfor the intravenous delivery of fluids and medication, and continuous electrocardiographicmonitoring was established to monitor heart rate and rhythm.
cross-sectional area measurements, images from a single heart recorded at 10 short-axis levels were analyzed in duplicate by each of two different echocardiographers. The
es ragged
e
artifact.
method of Shrout and Fleiss (17)and by the Cronbach alpha estimate of the reliability coefikietat (18). The reliability refers to the pr~po~~o~of the variation of an observation that is due to section to section variability in
sectional images (at
from3 to
250
FISHER ET AL. INTRACARDIAC ULTRASOUND-DERIVED
JACC Vol. 24, No. 1 July 1994:247-53
LEFT VENTRICULAR VOLUMES
Relation between left ve~t~cul~r volumes de!ermined by iac Mlt~sou~d and latex cast v0~l~rn~~ for ammal hearts eration alone. ~~t~s0~~d images recorded at O.S-cm intervals were used.
respectively). In viva, ~e~lo~yna~i~ variables. There was no sign cant change in heart rate and systemic arterial and I ventricular pressures between the intracardiac ultrasound and angiographic studies. Vo/unre determinarions. When all imaged sections were used, intracardiac ~lt~sou~d v end-systole correlated well with phy (Y = I .04X - 3.6, r = 0.91, end.diastolic and end-systolic values were cons rateiy, the relations we 1.04X - 3.5, r = 0.82, S .3 ml, respectively), alth r correspondence with en
tionswere riot si
ejection &action was des 4. Relation between left ventricular volumes determined by intracardiac ultrasound and latex cast volumes for hearts preserved by formalin fixation tier balloon distention. Ultrasound images recorded at O.S-cm intervals were used.
ic volume (cc)
contrast angiographic
volume (co)
fewer cross sections were
larger error
s
The choice ofa
of volume calculation acco tion was based on two
ventricle (23). second, the imaging orientaracardiac ultrasound beam yields images ideuited to Simpson rule reconstruction. Aitb~ug~ from int of view of ease of application it might bc to adapt single or biplane prolate ellipsoid a~goritbms to intracardiac ultrasound use because they require fewer component measurements, both the limited field of view and
of ~a~erest~~at~o~
at this
is study is ea titation and The results suggest that more complex an three~d~m~asioaal ~e~oastr~~tive tee construction are not necessary for ac nations in normal ventricles. In additiofl, a study, the ability of disto~ed venlricular
closely to the latex cast volumes b the angiographic volumes is in transthoracic studies. These differences
are ex
252
FISHER ET AL, MTRACARDIAC ULTRASOUND-DERIVED LEFT VEMlZlCULAR VOLUMES
the intrinsic diiferenccs in the two imaging techniques and the methods ofvohune calculation.First, even with the high resolution images obtained with high frequewcyintracardiac ic techniquesdefine the endocardialdevices, e innermost prominent trabeculae, blood in ad thus the volume within the muscufar ~~fQldin~s is not considered.Furthermore, the contribution of the left ventricular outflow track to total left ve recognizedby the Simpson rule meth
The
error ~nbcre~tin an ccc the fact that because the
c ultrasound tech
papWry muscles and trabeculae. dye (19)and the errors inke 20). Finalty, but extrer~~~y art
basis for the correction factors proposed by Kennedy et aP. (16)and used in this study. However, it might be argued that even with use of the correction factor, angio~~h~c volu
as it is at the skia. Thus
is farther removed fro catheter will track t
This study demonstrated a weaker c intmcardiac ultrasound and an systolc than at end-diastok. Thi of end-systolicvaluesavailab
we of trabecular In
s IS most ~rouounced at factors w also reflected in the COE&between ultrasound and angiographic
because systolic contraction tends to obscure
ecauseintracardiacultrasoundvolumes at end-systslewere generallysmallerthan those nxasurc-d the tendency to underestimate end-systolic volumes is due ~u~~~~~I~, the derivedultrasound ejection fractions to the fact that a catheter that is relativelyimmobile throughtended to overestimate their angiographic counterparts. However,althoughmost of the points were closely clustered, the correlationobtainedwasfair (0.69),and the slope was unity. Although encouraging, these data suggest that if this method is to be used for determinations of ejection fraction in the clinical setting, a normal range of values for this technique should be established, and the validation should be extended to include a wider range of ventricular fu . The ability of intravascularultrasound to provide accurate measurements of crosssectionalareas of arteries has been previously demonstrated I21,22), but the importance of a central coaxial catheter position has been emphasized. A coaxial position is important bxause my deviation from this alignment will result in
out the cardiac cycle will result in a disproportionate weighting of smaller apical volumes into the end-systolic volume determinations. it& the current state of the art of the following limitations of this iermination should be noted. First, vices, the field of view provided by intracardiacultrasound catheters is limited and prevents the recording of a full cross-sectional area in large hearts, icularlyat the mitral valve level. At this time, this woul preclude total volume dete~inat~o~s in most adult human hearts and possibly those of smaller animals with grossly dyskinetic segments. However, ongoing technologic advances should ameliorate this problem by providing lower frequency devices. Jt is expected that the optimal frequency
4. Carr KW. EngPer RL, Forsythe J , Johnson AD, Gosink B. of left ventricuPar ejection fraction by ~e~~a~~c~~ cross-sechd ~~~~o~ra~~y. Circulation 197959: I%-2rJ6. r MB,
s TA, et al. Left ve~t~~~~arvolume fr e~~~ar~iogra~~y. Cir~~~atioo 1979; an CL, Tow DE. and Vo~Mmes by 1999:60:760-6
8, F frac
8.
echo-
, Ports TA, Snider R., iciilldr PI ation of left ventricular volume graphic and a~~io~~a~~~~ comparisons. Circulation
J9~~;62:54~-57.
9.
11.
aendchen RV, Meerbaum S, Corday E. Assess~e~n of Ma~t~tative methods for 2-~~~e~sio~a~ ec~oc~~~o~~a~~y. Am J Cardiol
12.
Fernandez GC, Waggoner Winters icular volumes by two-dime aal echoaccurate approach Cir~~~at~o~ 1983;67:
13
, Daughters GT, et al. Limitations of comparing dimensional ecbo~~diog~~~y, myocardial markers and cinean~io~ra~~y. Am 3 Cardiol B982;50:512-9.
14. Schwartz SL, Gillam LD. Weintraub AR, et al. Bntracardiac echo ography in humans using a small-sized (6F). low frequency (12.5 ethods, imaging p!anes and clinical expertence. ultrasound cathe!er J Am Colt Cardiol 1 ;21:189-96. is. Bentivoglio LG. Griffith LD, Cuesta AJ, Geczy M. Wa ation of formulas for left ventricular volume using canine casts. J Appl Pbysiol 1972;33:365-8. 16. Kennedy JW, Trenholme SE. Kasser IS. Left ventricular volume and mass from single-plane cineangiograms.
ressure-area
linical Experiments.
14.
ique,
if corn
Wiley. 19X62-3. IS. Bernstein IN. Applied Verlag, 1985:390-l.
hfuhivariate
Analysis.
New
York:
New York: Springer-
19. Vas R, Diamond GA, Forrester JS. Whiting JS, Swan HJC. Computer enhancement of direct and venous-injected left ventricular contrast an-
21.
I. Wyatt HL. Heng MK, Meerbaum S, et ai. Cross-sectional echocardiography II. Analysis of mathematic models for quantifying volume of the formalin-ftxed left ventricle. Circulation 1980;61:11 J9-25. 2. Helak JW, Reichek N. Quantitation of human left ventricular mass and volume by two.dimensional echocardiography: in vitro anatomic validaShoukas AA, Weiss JL. Accurate volume ventricle by two204. dimensional echocardiography. Circulation 1979; 4. Weiss JL, Eaton LW, Kallman CH, Maughan WL. Accuracy of volume
22.
23.
aughan WL,
24.
raphic estimation of left ventricular volume. Cathet Cardiovasc Diagn 1995;1:7-12. Nishimura RA, Edwards W . Warnes CA, et al. Intravascular ultrasound imaging: in vitro validation and pathologic correlation. J Am Coil Cardiol 199O;t6:145-54. Nissen SE, Gurley JC, Grines CL, et al. Intravascular ultrasound assessment of lumen size and wall morphology in normal subjects and patients with coronary artery disease. Circulation 1991:84:JO87-99. Chase JS, Brisken AF, Maurer G, Siegel RJ. Geometric accurasy of ng. J Am Sot Echocardiogr 1992;5:577-87. intravascular uhrasoun JS, et al. Human left ventricular pressureFisher JP, McKay RG, area and pressure-volume analysis using echocardiographic autumatic boundary detection [abstract!. Circulation 1992;86 Suppl M-261.