(Circulation. 1997;96:1999-2008.)
© 1997 American Heart Association, Inc.
Articles |
Insights From Three-Dimensional Echocardiography Into the Mechanism of Functional Mitral Regurgitation
Direct In Vivo Demonstration of Altered Leaflet Tethering Geometry
From the Cardiac Ultrasound Laboratory and Cardiovascular Surgical Unit, Massachusetts General Hospital, Departments of Medicine and Surgery, Harvard Medical School, Boston, Mass.
Correspondence to Yutaka Otsuji, MD, Cardiac Ultrasound Laboratory, VBK508, Massachusetts General Hospital, 32 Fruit St, Boston, MA 02114.
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Abstract |
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Background Recent advances in three-dimensional (3D) echocardiography allow us to address uniquely 3D scientific questions, such as the mechanism of functional mitral regurgitation (MR) in patients with left ventricular (LV) dysfunction and its relation to the 3D geometry of mitral leaflet attachments. Competing hypotheses include global LV dysfunction with inadequate leaflet closing force versus geometric distortion of the mitral apparatus by LV dilatation, which increases leaflet tethering and restricts closure. Because geometric changes generally accompany dysfunction, these possibilities have been difficult to separate.
Methods and Results We created a model of global LV dysfunction by esmolol and phenylephrine infusion in six dogs, initially with LV expansion limited by increasing pericardial restraint and then with the pericardium opened. The mid-systolic 3D relations of the papillary muscle (PM) tips and mitral valve were reconstructed. Despite severe LV dysfunction (ejection fraction, 18±6%), only trace MR developed when pericardial restraint limited LV dilatation; with the pericardium opened, moderate MR accompanied LV dilatation (end-systolic volume, 44±5 mL versus 12±5 mL control, P<.001). Mitral regurgitant volume and orifice area did not correlate with LV ejection fraction and dP/dt (global function) but did correlate with changes in the tethering distance from the PMs to the anterior annulus derived from the 3D reconstructions, especially PM shifts in the posterior and mediolateral directions, as well as with annular area (P<.0005). By multiple regression, only changes in the PM-to-annulus distance independently predicted MR volume and orifice area (R2=.82 to .85, P=2x10-7 to 6x10-8).
Conclusions LV dysfunction without dilatation fails to produce important MR. Functional MR relates strongly to changes in the 3D geometry of the mitral valve attachments at the PM and annular levels, with practical implications for approaches that would restore a more favorable configuration.
Key Words: echocardiography • regurgitation • mitral valve
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Introduction |
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Recent advances in 3D echocardiography1 2 3 4 5 6 7 8 9 10 11 12 13 can potentially allow us to address uniquely 3D questions of scientific interest. One such question addresses the mechanism of functional MR in patients with LV dysfunction, a common complication of ischemic heart disease that influences long-term prognosis14 15 16 17 18 19 20 21 and for which competing explanations have been proposed. In 1963, Burch et al22 and Phillips et al23 proposed a possible role for PM dysfunction, but isolated PM dysfunction does not cause MR24 25 26 27 : MR occurs only when the PM and adjacent myocardium are damaged.25 26 Ogawa et al28 and Godley et al29 reported that in patients with ischemic MR, the mitral leaflet coaptation was apical to the mitral annulus in end systole, a pattern called "incomplete mitral leaflet closure" and attributed to dyskinesia or distortion of the region of the LV from which the PMs arise, restricting the ability of the leaflets to move toward closure.30 31 32 33 34 35 36 37 38 39 40 Recently, however, Kaul et al41 reported a canine experiment suggesting that ischemic MR was not related to dysfunction of either the PMs or the immediately adjacent LV myocardium but rather only to global LV dysfunction, decreasing the ventricular force acting to close the leaflets: their model allowed separate perfusion of the PM and non-PM regions through coronary cannulas. Thus, a confusing variety of often contradictory results in different clinical and experimental settings supports conflicting mechanistic proposals; in addition, mechanistic postulates, such as the suggestion that increased LV sphericity restricts leaflet closure by displacing the PMs,32 33 34 35 36 remain in need of direct proof.
On the basis of physical principles, it seems reasonable that the
mechanism of ischemic MR can be understood in terms of an
altered force balance on the mitral leaflets in systole: a combination
of increased tethering forces that restrain the leaflets from closing
and result from an altered 3D geometry of leaflet attachments
associated with LV dilatation and decreased ventricular
forces that act to close the mitral leaflets (Fig 1A
).
Because the mass of the mitral leaflets is relatively small, however,
in principle it should not take much force to close them unless they
are abnormally tethered, consistent with in vitro studies with
excised valves.42 43 44 Therefore, we can propose the
hypothesis that in LV dysfunction, MR relates primarily to an altered
geometry of mitral leaflet attachments resulting from LV dilatation as
opposed to systolic dysfunction per se. This is difficult to
test in the usual clinical environment, in which altered function and
geometry tend to occur together and geometric assessments are subject
to the limitations of two-dimensional techniques such as standard
echocardiography, requiring multiple views to be
combined for spatial appreciation.45 The purpose of this
study was therefore to overcome these limitations and test this
hypothesis with quantitative 3D echocardiography in
an animal model designed to produce LV dysfunction both with and
without prominent dilatation. Studying this mechanism is important in
terms of understanding basic concepts of mitral valve function as well
as therapeutic implications for surgical therapy to address geometric
distortions of the mitral
apparatus.16 17 46 47 48 49
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Methods |
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Model
Specifically, six mongrel dogs (19 to 30 kg) were anesthetized with pentobarbital (30 to 50 mg/kg IV), intubated, and ventilated and then underwent left thoracotomy. Micromanometer-tipped Millar catheters were placed in the LV and LA, and a Transonic flowmeter was placed firmly on the aortic root to record pressures and aortic flow rate continuously with an ECG tracing. The dogs were placed on right heart bypass by draining of all venous return from the right atrium and pumping of the filtered and oxygenated blood by calibrated roller pump into the pulmonary artery through a wide-bore cannula.50 This procedure allowed control of cardiac output as well as suspension of respiration during data acquisition to achieve the most stable reconstructions. Initially, the cardiac output was set between 1100 and 1200 mL/min to maintain the typical output before right heart bypass. After baseline hemodynamic recording and echocardiographic imaging (see below), the pericardial sac was reduced in size by folding the pericardium over itself parallel to the long axis of the heart and suturing to make it smaller and minimize LV dilatation when global dysfunction was induced. Reversible LV systolic dysfunction was initially produced with the tightened pericardium by infusion of a combination of esmolol (250 µg/kg load, with a maintenance infusion beginning at 25 µg·kg-1·min-1 and increasing by 25 µg·kg-1·min-1 at 5-minute intervals to a maximum of 500 µg·kg-1·min-1, titrated to reduce LVEF to
25% in the presence of increased
afterload) and phenylephrine (2 to 12
µg·kg-1·min-1);
if phenylephrine failed to increase afterload sufficiently
to reduce EF, the descending thoracic aorta was partially constricted
(n=2) to achieve this goal. LV dilatation was limited both by
tightening the pericardium and by using the roller-pump right heart
bypass mechanism to reduce cardiac output by 50%. Reducing output was
also necessary because, with increased pericardial restraint and LV
dysfunction, maintained cardiac output produced severely increased LV
diastolic pressures and hemodynamic
instability. After echo imaging, the pericardium was incised open to
permit acute dilatation, cardiac output was restored to its baseline
value, and imaging was repeated. When the pericardium was opened, LV
size, EF, and blood pressure tended to increase, so esmolol and
phenylephrine were titrated to restore values comparable to
those in the stage with a closed pericardium.
3D Echo Data Collection
3D echo data were acquired by use of an epicardial 3D echo
technique, with a 5-MHz transducer for highest resolution, scanning the
heart in a series of views rotated about the LV apex, viewed through a
water bath. A multiplane probe that permits rotation of an ultrasound
crystal array around an axis from a fixed transducer position was used.
For optimal 3D reconstruction, the probe was positioned to align the
axis of rotation through the center of the mitral valve and parallel to
the long axis of the LV. The probe was interfaced with a
Hewlett-Packard Sonos 1500 sector scanner containing special 3D
software that allowed us to record rotated images at angular
increments (4°) from 0° to 180°; ECG gating was used to obtain 45
planes at mid systole, when the mitral leaflets closed most
effectively.29 51 Because blood
oxygenation could be maintained with a membrane
oxygenator, respiration was suspended during the data acquisition
to facilitate accurate 3D reconstruction. Images were recorded
on videotape as well as on magneto-optical disks as digital data and
then transferred to a Silicon Graphics workstation for tracing and
further analysis.
Data Analysis
LV volumes were obtained with a biplane Simpson
method.52 LV sphericity was determined by a method
analogous to that of Kono et al32 33 34 35 36 as the actual LV
volume divided by the volume of a sphere with a diameter equal to the
LV longest axis. Total MR stroke volume was obtained as LV ejection
volume minus forward aortic stroke volume (in the absence of aortic
insufficiency), determined with the calibrated Transonic flowmeter.
Mitral regurgitant orifice area was obtained by Gorlin's method as
modified by Yellin et al {MROA=
(1.1xRSV)/[0.31xRTx(mPG)1/2], where MROA is MR orifice
area (mm2), RSV is regurgitant stroke volume (mL), RT is
regurgitant time in each beat (seconds), and mPG is the mean LV-LA
pressure gradient (mm Hg)}.53 54 55 The IMLC or apical
tenting area29 was measured in the apical four-chamber
view as the area between the mitral leaflets and the line connecting
the annular hinge points at mid systole.56 The proximal MR
jet width by Doppler color flow mapping was also measured in the
apical four- and two-chamber views, and the proximal jet
cross-sectional area was calculated on the basis of the elliptical
shape of this area seen on ultrasound images (area=
xdiameter1xdiameter2/4).57 58 59
3D PM–Mitral Valve Relations
To design these measurements, we reviewed the reasoning of Burch
et al,60 who in 1968 originally postulated a role for 3D
vector geometry in determining the effect of PM force: "In the
normal-sized heart, the long axis of the papillary muscle is oriented
almost perpendicular to the atrioventricular ring. This
orientation of the papillary muscles provides a mechanical advantage in
that tension developed by the papillary muscles is applied almost
perpendicular to the mitral valve leaflets. On the other hand, with
ventricular dilatation the papillary muscles migrate
laterally, so that tension developed by the papillary muscles is
applied tangentially to the mitral leaflets. The greater the lateral
displacement of the papillary muscles the greater the mechanical
disadvantage." Other authors have proposed similar
concepts.61 62 The main purposes of the 3D
analysis were therefore (1) to provide a convenient and
objective reference frame to describe the relationship of the mitral
valve to the PMs, namely, the least-squares plane fitted to the annular
hinge points, which is a plane that has the least deviation of annular
points about it,8 and (2) to determine, by use of this
reference frame, whether the PM tips tethering the leaflets have been
displaced apically, mediolaterally, or posteriorly, potentially
impairing the ability of the leaflets to coapt. (A lateral component
will in principle act to impair coaptation at the leaflet center; an
excessive posterior component will impair the ability of the leaflets
to meet each other by tethering the posterior leaflet more posteriorly
and restraining the anterior leaflet closer to the more apical PM tips,
producing the impression of restricted motion that is often seen
clinically [Fig 1B
].) A series of uniquely 3D measurements that
cannot be made in any two-dimensional view were tested for their
ability to correlate with the development of MR in this model. The
steps needed to analyze these relations are shown in Fig 2; descriptions of the measurements reported and how
they are made are listed in Table 1. Rotated images were
retrieved to analyze LV and mitral valve geometry at mid
systole. Appreciation of cardiac structures was enhanced by
simultaneous display of intersecting views on the graphics
monitor of a Silicon Graphics work station (Fig 2A) by a technique
called 3D texture mapping. Points were traced to permit
analysis of identified structures, including PMs, PM tips, LV
endocardium, mitral leaflets, and annulus, with different colors used
to code and separate tracings of different structures (B). The
ventricular borders of the mitral leaflets were traced. The
mitral annulus was identified as the hinge points of the leaflets,
defined by their insertion on the LV walls posteriorly and their
junction with the aortic root and cusps anteriorly. Review of video
loops was used to confirm where the moving leaflets hinged. The aortic
annulus was similarly identified by the hinge points of the aortic
cusps. The PMs were traced as muscular structures protruding into the
LV cavity, and the PM tips were determined by review of several
adjacent images from the 3D data set to find the point at the tip of
each PM lying closest to the base of the heart and, in particular, to
the anterior mitral annulus. This could be checked by observing the
relation of any traced point to the annulus in reconstructed views,
such as those in Fig 2B. The entire set of traced data points (C) was
then used to generate an endocardial surface (D, E) by use of a
surfacing algorithm applied for LV volume63 ; points on the
surface adjacent to structures such as the PMs were color-coded.
Spatial relations of the mitral valve complex were then established (F,
G): (1) the least-squares plane fitted to the annulus; (2) the centers
of mass or centroids of the mitral and aortic annuli; (3) the PM tips;
and (4) the distances from the PM tips to the mitral annular
centroid.
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The next step was to measure the tethering length over which the mitral
leaflets and chordae are stretched between the PMs and the relatively
fixed fibrous portion of the annulus.47 This was done by
determining the distance from each PM tip to the midportion of the
anterior mitral annulus, labeled PM-MA in Fig 3A. In
practice, this distance was measured to a consistent point
defined by the medial trigone of the aortic valve, that is, the medial
junction of the aortic and mitral annuli (Fig 3A; Fig 4B, red points). This point had the advantage that the
line connecting it with the mitral annular centroid roughly bisected
the line connecting the PM tips, so that symmetrical outward
displacements of the PMs appeared symmetrical relative to this line.
Changes in these tethering distances from baseline to the LV
dysfunction stages were measured and also analyzed in terms of
their three components: 
x, reflecting mediolateral PM
shifts (broader LV); y, reflecting posterior PM shifts;
and z, reflecting shifts parallel to the LV long axis
(Fig 3B). Changes were also measured in D, the distance between the PM
tips (Fig 3A), and the angle 
between the PM-to-annulus line and the
least-squares annular plane, which tends to decrease as the LV dilates,
as shown in Fig 3B.
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Mitral annular cross-sectional area was measured from the 3D reconstruction at mid systole.8 The peak transmitral force generated by LV contraction and acting to close the mitral leaflets was calculated as the peak transmitral pressure gradient times the annular cross-sectional area.64 65
Accuracy of 3D Echocardiographic Measurements
The accuracy of 3D echocardiographic
measurements was verified by comparing 28 distances between points
measured by 3D echocardiography in a
ventricular phantom with those measured directly by an
array of eight sonomicrometer crystals (Sonometrics) placed
to reflect two typical PM tip positions and six points around the
mitral annular circumference. The sonomicrometers were
imaged by the 3D echocardiographic rotational method,
and distances between them were measured from the reconstructed
images.
Statistical Analysis
Hemodynamic variables (heart rate, maximal
LV pressure, LA pressure, LV-LA pressure gradient, LV dP/dt, aortic
forward stroke volume, LV ejection volume, and MR stroke volume), LV
volumes and EF, and measures of mitral valve geometry and transmitral
leaflet closure force were compared among the three stages and six dogs
by two-way ANOVA. Significant differences by ANOVA were explored by
paired t tests; such differences are protected by Fisher's
F-test criterion for multiple comparisons.66 Because of
the number of variables being studied, the significance of the
overall ANOVA was assessed at the conservative value of
P<.005.67 The determinants of MR stroke volume
and its orifice area were explored by univariate and
stepwise multiple linear regression analysis, with the absolute
value and changes relative to the control stage of the following
variables entered into the model: (1) the 3D measures of the
geometry of the mitral leaflet attachments, including the PM-to-annulus
distance (PM-MA), its x, y, and z
components and angle relative to the annulus, the distance between the
two PMs, and the mitral annular area; (2) LV measures, including LV
end-diastolic and end-systolic volume, EF,
end-diastolic and end-systolic sphericity indices,
and maximal dP/dt; and (3) the transmitral leaflet closure force as
calculated above. Because of the symmetrical changes in the PMs, the
changes in their relations (PM-MA, its components, and its angle
relative to the annular plane) were summed for purposes of the
analysis. A similar set of variables was used to explore
the correlates of IMLC area (apical tenting) and of LV
end-systolic sphericity index. Variables were entered in
the order suggested by the multiple regression model based on the F to
enter or remove.
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Hemodynamics
Maximal LV pressure was not significantly different among the control and global LV dysfunction stages, although dP/dt decreased and LA pressure increased, decreasing the mean transmitral pressure gradient (but not the total transmitral leaflet closure force: see below) (Table 2
). Pericardial restraint and reduced
cardiac output limited increases in LV volume with global dysfunction.
With pericardial removal and restoration of cardiac output, cardiac
size, LVEF, and LV ejection volume also increased. Forward aortic
stroke volume was decreased (in part by design) with global LV
dysfunction in the presence of limitation to LV dilatation but was
restored in the stage at which LV dilatation was permitted. MR volume
did not change from the control stage to that with global LV
dysfunction and limited dilatation but increased considerably when the
limitations to LV dilatation were removed.
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LV and Mitral Valve Indices and Transmitral Leaflet Closure
Force
Changes in geometric measures of the mitral valve complex were
initially limited because of the limited changes in LV size (Table 3). However, removal of the limitation to LV dilatation
caused increases in IMLC area, distance from the PM tip to the anterior
annulus, LV sphericity index, and mitral annular area and a decrease in
the angle between the PM-to-annulus line and the least-squares plane of
the annulus. The transmitral leaflet closure force acting on the mitral
valve tended to increase, corresponding to the increased mitral annular
area, but with a value of only P=.04.
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Changes in MR
Fig 4A shows changes in MR indicated by maximal Doppler color
flow mapping jet area in an apical view. MR increased from none in the
control stage to trace with global LV dysfunction and pericardial
restraint and then to moderate with removal of the pericardium and
apical tenting of the leaflets. There were corresponding changes in the
mitral apparatus viewed from the apex, as seen in Fig 4B, with the mitral annulus viewed en face: as the LV dilated, the PMs were
displaced outward (medially and laterally), away from the center of the
annulus, and posteriorly, increasing the mitral valve tethering length
between the PMs and anterior annulus; the annular area to be occluded
by the valve also increased.
Univariate predictors of MR stroke volume were the absolute value and its change from the control stage of the PM-to-annulus tethering length and its x and y, or mediolateral and posterior, components (there was no significant difference in the z, or axial, components among stages); the PM-to-annulus angle and PM tip separation; mitral annular area; IMLC area; LV end-diastolic and end-systolic volumes and sphericity indices; and transmitral leaflet closure force. MR stroke volume did not significantly correlate with LVEF and maximal LV dP/dt as measures of global LV systolic function. Multiple linear regression analysis identified the change from the control stage in the PM-to-annulus tethering length as the only independent factor determining MR stroke volume (R2=.82, P=2x10-7, SEE=1.3). Univariate analysis showed the same predictors for the MR orifice area except for transmitral leaflet closure force, and the change in the tethering length (PM to annulus) was similarly selected by the multiple regression analysis as the only independent factor determining the MR orifice area (R2=.85, P=6x10-8, SEE=1.8). The change in this tethering length was also the only independent predictor of IMLC area (R2=.88, P=8x10-9, SEE=0.14), reflecting in part the high correlations this tethering length had with other measures of mitral valve tethering geometry. There were strong univariate associations between end-systolic sphericity index and all measures of mitral valve tethering geometry, including the PM-to-annulus distance, the angle between the PM-to-annulus line and the annular plane, the PM tip separation, and annular area; multiple linear regression analysis identified independent contributions from LV end-systolic volume primarily, as well as PM tip separation (R2=.93, P=1x10-9, SEE=0.02). Proximal jet cross-sectional area correlated well with MR orifice area obtained by the modified Gorlin's method, with overestimation when the MR was more severe (y=3.2x-2.3, r=.90, SEE=7.3 mm2).
MR stroke volume and orifice area are plotted versus the changes from
baseline in the PM-to-annulus tethering length in Figs 5 and 6. Although the data suggest some degree of
curvature, exponential fits yielded lower values of
R2, .70 and .73 compared with .82 and .85 for
the linear fits.
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Accuracy of 3D Echocardiographic Measurements
The distance between sonomicrometric transducers measured by 3D
echo correlated and agreed well with those by sonomicrometry
(y=1.0x-0.3, R2=.99,
SEE=1.0 mm, P=2x10-28) (Fig 7A); the mean difference between measurements by the two
different methods was 0.04±1.0 mm (not significant versus 0; Fig 7B).
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Discussion |
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The results of this study show that LV dysfunction, even when severe, fails to produce important MR without LV dilatation. In contrast, MR does develop if LV dilatation is allowed to occur, even if EF rises slightly. Thus, MR with global LV dysfunction relates to LV dilatation, with its potential for associated geometric changes. 3D echocardiography directly confirmed the presence of such changes, including an increased distance over which the mitral leaflets are tethered from the PMs to the anterior annular ring, as well as an increased mitral annular area that must be covered. These changes stretch the leaflets widely over the annulus and restrict their ability to close effectively at the annular level, resulting in apical tenting relative to the annular ring (Fig 1B
). The measured tethering
length from PM tip to annulus, which most strongly predicts MR stroke
volume and orifice area, did not appreciably change in a direction
parallel to the long axis of the LV, reflecting lack of important acute
leaflet-chordal stretch in that direction. Instead, the changes in
tethering length relate to mediolateral and posterior PM shifts,
redirecting PM tension away from the axial direction that effectively
opposes LV force and diverting the leaflets away from
closure.60 61 62 Of note is that these measurements demand
the spatial appreciation provided by 3D
echocardiography to recognize the superior tips of
the PMs, and the least-squares plane and medial trigone of the annulus
as a consistent reference frame for measurements. The results
also show that increased sphericity index correlates strongly with
measures of mitral leaflet tethering, confirming the mechanistic
postulate of Kono et al32 33 34 35 36 that sphericity correlates
with MR because of changes in PM position.
Limitations
The spectrum of MR in patients with acute and chronic LV
dysfunction includes a wide range of geometric distortions and wall
motion abnormalities not reflected in the present model as well as
a spectrum of PM tip geometry and potentially changes in leaflet length
as well. Nevertheless, the purpose of this study was specifically to
develop a model that could separate changes in contractile function
from major changes in ventricular size and to evaluate MR
and the 3D geometric relations of the mitral valve in such a model.
Future studies are required to evaluate changes in segmental function
with and without pericardial restraint to limit shape change. In
patients, similar analysis should be possible with 3D
echocardiography, but the medial PM often has two
heads, which may be analyzed separately or on the basis of
their centroid as the effective point toward which the resultant vector
of PM tension is directed. Of note is that when tethering length was
measured from the PM tip to the mitral annular centroid rather than the
anterior annulus, changes were smaller and less consistent.
This is because, as the LV dilates, and with it the posterior
nonfibrous portion of the annulus, the PMs and annular centroid are
both displaced posteriorly relative to the anterior annular ring. This
can help explain why Boltwood et al45 found no major
differences in patients with and without MR with respect to distances
from PM tip to annular center, as opposed to the entire span from PM
tip to anterior annulus.
Practical Implications
These results are consistent with clinical observations
regarding patients with severely reduced global LV systolic
function but no MR.68 A review of 1366 consecutive
patients studied echocardiographically with LVEFs
<30% (mean, 17.8±6%) found that 190 (14%) had no MR by Doppler
color flow mapping. In this group, functional MR was not determined
primarily by severely reduced LV systolic function by itself
but rather related more strongly to changes in LV shape and concomitant
changes in the position of the mitral leaflets, consistent with
abnormal tethering by displaced attachments. The findings of the
present study also suggest the possibility that surgical
approaches, such as those at the time of myocardial
revascularization, could be of potential benefit by
restoring 3D mitral valve geometry toward normal. Such maneuvers might
include increased pericardial restraint to limit LV size and leaflet or
chordal elongation to permit more effective bridging of an increased
gap between the PM tips and anterior mitral annulus. It is conceivable
that part of any benefit from surgical myoplasty might also relate to
reducing LV cavity size by wrapping skeletal muscle around the heart. A
recently described operation that resects ventricular
muscle from the posterior wall between the PMs in patients with failing
ventricles may reduce MR, in part, by moving the PMs closer together
and decreasing their tethering of the leaflets.69 Although
insertion of an annuloplasty ring can limit annular area and improve
coaptation, clinical observations suggest that this is not always the
case. If the ring were to hoist the posterior mitral annulus anteriorly
but the PMs were to remain posterior, the effective tethering length
between PMs and anterior annulus might not change appreciably, thereby
maintaining the leaflet tension that limits coaptation, despite the
reduction in annular area. This can potentially explain occasional
observations of persistent apical tenting and MR in the presence of
ring implantation. Finally, the importance of the PM-to-annulus
tethering length can have implications for the sizing and insertion of
mitral homografts.70
Conclusions
LV dysfunction without prominent dilatation fails to produce
important MR. Functional MR relates strongly to changes in the 3D
geometry of the mitral valve attachments at the PM and annular levels,
with practical implications for approaches that would result in a more
favorable configuration of the valve that reduces or eliminates
regurgitation.
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Selected Abbreviations and Acronyms |
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Acknowledgments |
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This study was supported in part by grant HL-53702 from the National Institutes of Health, Bethesda, Md (Dr Levine) and by a donation from Bernard L. Adams, Holyoke, Mass. Dr Otsuji was supported in part by a fellowship of Kagoshima University, Kagoshima, Japan. Dr Song was supported by a fellowship from the Korean Science and Engineering Foundation, Seoul, and by the Asan Medical Center, Seoul, Korea. We thank Melissa Fox for her expert assistance and John B. Newell for his statistical consultation.
Received December 16, 1996; revision received March 14, 1997; accepted March 20, 1997.
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References |
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1. Geiser EA, Ariet M, Conetta DA, Lupkiewicz SM, Christie LG Jr, Conti CR. Dynamic three-dimensional echocardiographic reconstruction of the intact human left ventricle: technique and initial observations in patients. Am Heart J. 1982;103:1056-1065.[Medline] [Order article via Infotrieve]
2. Ghosh A, Nanda NC, Maurer G. Three-dimensional reconstruction of echocardiographic images using the rotation method. Ultrasound Med Biol. 1982;8:655-661.[Medline] [Order article via Infotrieve]
3. Moritz WE, Pearlman AS, McCabe DH, Medema DK, Ainsworth ME, Boles MS. An ultrasonic technique for imaging the ventricle in three dimensions and calculating its volume. IEEE Trans Biomed Eng. 1983;30:482-491.[Medline] [Order article via Infotrieve]
4. Nixon JV, Saffer SI, Lipscomb K, Blomqvist CG. Three-dimensional echoventriculography. Am Heart J. 1983;106:435-443.[Medline] [Order article via Infotrieve]
5. Sapoznikov D, Fine DG, Mosseri M, Gotsman MS. Left ventricular shape, wall thickness and function based on three-dimensional reconstruction echocardiography. Comput Cardiol. 1987;495-498.
6. Collins SM, Chandran KB, Skorton DJ. Three-dimensional cardiac imaging. Echocardiography. 1988;5:311-319.
7. Martin RW, Graham MM, Kao R, Bashein G. Measurement of left ventricular ejection fraction and volumes with three-dimensional reconstructed transesophageal ultrasound scans: comparison to radionuclide and thermal dilution measurements. J Cardiothorac Anesth. 1989;3:260-268.[Medline] [Order article via Infotrieve]
8.
Levine RA, Handschumacher MD, Sanfilippo AJ, Hagege
AA, Harrigan P, Marshall JE, Weyman AE. Three-dimensional
echocardiographic reconstruction of the mitral valve,
with implications for the diagnosis of mitral valve prolapse.
Circulation. 1989;80:589-598.
9. King DL, King DL Jr, Shao MYC. Three-dimensional spatial registration and interactive display of position and orientation of real-time ultrasound images. J Ultrasound Med. 1990;9:525-532.[Abstract]
10. Gopal AS, King DL, Katz J, Boxt LM, King DL Jr, Shao MY. Three-dimensional echocardiographic volume computation by polyhedral surface reconstruction: in vitro validation and comparison to magnetic resonance imaging. J Am Soc Echocardiogr. 1992;5:115-124.[Medline] [Order article via Infotrieve]
11. Pandian NG, Nanda NC, Schwartz SL, Fan P, Cao QL, Sanyal R, Hsu TL, Mumm B, Wollschlager H, Weintraub A. Three-dimensional and four-dimensional transesophageal echocardiographic imaging of the heart and aorta in humans using a computed tomographic imaging probe. Echocardiography. 1992;9:677-687.[Medline] [Order article via Infotrieve]
12. Belohlavek M, Foley DA, Gerber TC, Greenleaf JF, Seward JB. Three-dimensional ultrasound imaging of the atrial septum: normal and pathologic anatomy. J Am Coll Cardiol. 1993;22:1673-1678.[Abstract]
13. Salustri A, Becker AE, Herwerden LV, Vletter WB, Ten Cate FJ, Roelandt JRTC. Three-dimensional echocardiography of normal and pathologic mitral valve: a comparison with two-dimensional transesophageal echocardiography. J Am Coll Cardiol. 1996;27:1502-1510.[Abstract]
14. Rankin JS, Hickey MSJ, Smith LR, Muhlbaier L, Reves JG, Pryor DB, Wechsler AS. Ischemic mitral regurgitation. Circulation. 1989;79(suppl I):I-116-I-121.
15. Fleischmann KE, Goldman L, Robiolio PA, Lee RT, Johnson PA, Cook EF, Lee TH. Echocardiographic correlates of survival in patients with chest pain. J Am Coll Cardiol. 1994;23:1390-1396.[Abstract]
16. Rankin JS, Hickey MSJ, Smith LR, DeBruijn NP, Sheikh KH, Sabiston DC Jr. Current concepts in the pathogenesis and treatment of ischemic mitral regurgitation. In: Vetter HO, Hetzer R, Schmutzler H, eds. Ischemic Mitral Incompetence. New York, NY: Springer-Verlag; 1991:157-178.
17. Frater RWM, Cornelissen P, Sisto D. Mechanisms of ischemic mitral insufficiency and their surgical correction. In: Vetter HO, Hetzer R, Schmutzler H, eds. Ischemic Mitral Incompetence. New York, NY: Springer-Verlag; 1991:117-130.
18. Barzilai B, Gessler C Jr, Perez JE, Schaab C, Jaffe AS. Significance of Doppler-detected mitral regurgitation in acute myocardial infarction. Am J Cardiol. 1988;61:220-223.[Medline] [Order article via Infotrieve]
19. Lehmann KG, Francis CK, Dodge HT, and the TIMI Study Group. Mitral regurgitation in early myocardial infarction: incidence, clinical detection, and prognostic implications. Ann Intern Med. 1992;117:10-17.
20. Adler DS, Goldman L, O'Neil A, Cook EF, Mudge GH Jr, Shemin RJ, DiSesa V, Cohn LH, Collins JJ Jr. Long-term survival of more than 2,000 patients after coronary artery bypass grafting. Am J Cardiol. 1986;58:195-202.[Medline] [Order article via Infotrieve]
21. Dion R. Ischemic mitral regurgitation: when and how should it be corrected? J Heart Valve Dis. 1993;2:536-543.[Medline] [Order article via Infotrieve]
22. Burch GE, De Pasquale NP, Phillips JH. Clinical manifestations of papillary muscle dysfunction. Arch Intern Med. 1963;112:112-117.
23. Phillips JH, Burch GE, De Pasquale NP. The syndrome of papillary muscle dysfunction. Ann Intern Med. 1963;59:508-520.
24. Miller GE Jr, Cohn KE, Kerth WJ, Selzer A, Gerbode F. Experimental papillary muscle infarction. J Thorac Cardiovasc Surg. 1968;56:611-616.[Medline] [Order article via Infotrieve]
25. Tsakiris AG, Rastelli GC, Amorim D, Titus JL, Wood EH. Effect of experimental papillary muscle damage on mitral valve closure in intact anesthetized dogs. Mayo Clin Proc. 1970;45:275-285.[Medline] [Order article via Infotrieve]
26.
Mittal AK, Langston M Jr, Cohn KE, Selzer A, Kerth
WJ. Combined papillary muscle and left ventricular
wall dysfunction as a cause of mitral regurgitation: an
experimental study. Circulation. 1971;44:174-180.
27. Hider CF, Taylor DEM, Wade JD. The effect of papillary muscle damage on atrioventricular valve function in the left heart. Q J Exp Physiol. 1965;50:15-22.
28. Ogawa S, Hubbard FE, Mardelli TJ, Dreifus LS. Cross-sectional echocardiographic spectrum of papillary muscle dysfunction. Am Heart J. 1979;97:312-321.[Medline] [Order article via Infotrieve]
29.
Godley RW, Wann LS, Rogers EW, Feigenbaum H, Weyman
AE. Incomplete mitral leaflet closure in patients with papillary
muscle dysfunction. Circulation. 1981;63:565-571.
30.
Izumi S, Miyatake K, Beppu S, Park YD, Nagata S,
Kinoshita N, Sakakibara H, Nimura Y. Mechanism of mitral
regurgitation in patients with myocardial infarction: a
study using real-time two-dimensional Doppler flow imaging and
echocardiography. Circulation. 1987;76:777-785.
31. Kisanuki A, Otsuji Y, Kuroiwa R, Murayama T, Matsushita R, Shibata K, Yutsudo T, Nakao S, Nomoto K, Tomari T, Tanaka H. Two-dimensional echocardiographic assessment of papillary muscle contractility in patients with prior myocardial infarction. J Am Coll Cardiol. 1993;21:932-938.[Abstract]
32. Kono T, Sabbah HN, Rosman H, Alam M, Jafri S, Stein PD, Goldstein S. Mechanism of functional mitral regurgitation during acute myocardial ischemia. J Am Coll Cardiol. 1992;19:1101-1105.[Abstract]
33. Kono T, Sabbah HN, Stein PD, Brymer JF, Khaja F. Left ventricular shape as a determinant of functional mitral regurgitation in patients with severe heart failure secondary to either coronary artery disease or idiopathic dilated cardiomyopathy. Am J Cardiol. 1991;68:355-359.[Medline] [Order article via Infotrieve]
34. Sabbah HN, Kono T, Rosman H, Jafri S, Stein PD, Goldstein S. Left ventricular shape: a factor in the etiology of functional mitral regurgitation in heart failure. Am Heart J. 1992;123:961-966.[Medline] [Order article via Infotrieve]
35. Kono T, Sabbah HN, Rosman H, Alam M, Jafri S, Stein PD, Goldstein S. Left ventricular shape is the primary determinant of functional mitral regurgitation in heart failure. J Am Coll Cardiol. 1992;20:1594-1598.[Abstract]
36.
Sabbah HN, Kono T, Stein PD, Mancini GBJ, Goldstein
S. Left ventricular shape changes during the course
of evolving heart failure. Am J Physiol. 1992;263:H266-H270.
37. Llaneras MR, Nance ML, Streicher JT, Linden PL, Downing SW, Lima JAC, Deac R, Edmunds LH Jr. Pathogenesis of ischemic mitral insufficiency. J Thorac Cardiovasc Surg. 1993;105:439-443.[Abstract]
38. Llaneras MR, Nance ML, Streicher JT, Lima JAC, Savino JS, Bogen DK, Deac RFP, Ratcliffe MB, Edmunds LH Jr. Large animal model of ischemic mitral regurgitation. Ann Thorac Surg. 1994;57:432-439.[Abstract]
39.
Gorman RC, McCaughan JS, Ratcliffe MB, Gupta KB,
Streicher JT, Ferrari VA, St John-Sutton MG, Bogen DK, Edmunds LH Jr.
Pathogenesis of acute ischemic mitral
regurgitation in three dimensions. J Thorac
Cardiovasc Surg. 1995;109:684-693.
40. Komeda M, Glasson JR, Maclsaac A, Bolger AF, Osterle SN, Niczyporuk MA, Daughters GT, Ingels NB Jr, Miller DC. Circumflex coronary artery occlusion produces incomplete mitral leaflet closure of the anterior-lateral commissure in intact dogs. Circulation. 1995;92(suppl I):I-356. Abstract.
41.
Kaul S, Spotnitz WD, Glasheen WP, Touchstone DA.
Mechanism of ischemic mitral regurgitation: an
experimental evaluation. Circulation. 1991;84:2167-2180.
42. Schwammenthal E, He S, Weyman AE, Yoganathan AP, Levine RA, Fontaine AA. The impact of driving pressure on effective regurgitant orifice area in incomplete mitral valve closure. J Am Coll Cardiol. 1994;23:176A. Abstract.
43. He S, Fontaine AA, Ellis JT, Schwammenthal E, Yoganathan AP, Levine RA. An integrated mechanism for functional mitral regurgitation: leaflet restriction vs coapting force: in vitro studies. J Am Coll Cardiol. 1996;27:238A. Abstract.
44. Fontaine AA, He S, Ellis JT, Schwammenthal E, Levine RA, Yoganathan AP. Dynamic orifice area variations in functional mitral regurgitation: in vitro reproduction and mechanistic insights. J Am Coll Cardiol. 1996;27:37A. Abstract.
45.
Boltwood CM, Tei C, Wong M, Shah PM.
Quantitative echocardiography of the mitral complex
in dilated cardiomyopathy: the mechanism of
functional mitral regurgitation.
Circulation. 1983;68:498-508.
46. Miller DC, Stinson EB, Rossiter SJ, Oyer PE, Reitz BA, Shumway NE. Impact of simultaneous myocardial revascularization on operative risk, functional result, and survival following mitral valve replacement. Surgery. 1978;84:848-857.[Medline] [Order article via Infotrieve]
47. Carpentier A, Chauvaud S, Fabiani JN, Deloche A, Relland J, Lessana A, D'Allaines C, Blondeau P, Piwnica A, Dubost C. Reconstructive surgery of mitral valve incompetence: ten-year appraisal. J Thorac Cardiovasc Surg. 1980;79:338-348.[Abstract]
48. David TE. Techniques and results of mitral valve repair for ischemic mitral regurgitation. J Card Surg. 1994;9(suppl):274-277.
49. Cohn LH. Surgical treatment of ischemic mitral regurgitation by repair and replacement. In: Vetter HO, Hetzer R, Schmutzler H, eds. Ischemic Mitral Incompetence. New York, NY: Springer-Verlag; 1991:179-186.
50.
Choong CY, Abascal VM, Thomas JD, Guerrero JL,
McGlew S, Weyman AE. Combined influence of
ventricular loading and relaxation on the transmitral flow
velocity profile in dogs measured by Doppler
echocardiography. Circulation. 1988;78:672-683.
51.
Schwammenthal E, Chen C, Benning F, Block M, Breithardt
G, Levine R. Dynamics of mitral regurgitant flow and orifice
area: physiologic application of the proximal flow convergence method:
clinical data and experimental testing. Circulation. 1994;90:307-322.
52. Schiller NB, Shah PM, Crawford M, DeMaria A, Devereux R, Feigenbaum H, Gutgesell H, Reichek N, Sahn D, Schnittger I, Silverman NH, Tajik AJ. Recommendations for quantitation of the left ventricle by two-dimensional echocardiography. J Am Soc Echocardiogr. 1989;2:358-367.[Medline] [Order article via Infotrieve]
53. Gorlin R, Dexter L. Hydraulic formula for the calculation of the cross-sectional area of the mitral valve during regurgitation. Am Heart J. 1952;43:188-205.[Medline] [Order article via Infotrieve]
54.
Yellin EL, Yoran C, Sonnenblick EH, Gabbay S, Frater
RWM. Dynamic changes in the canine mitral regurgitant orifice
area during ventricular ejection. Circ
Res. 1979;45:677-683.
55. Yoran C, Yellin EL, Becker RM, Gabbay S, Frater RWM, Sonnenblick EH. Dynamic aspects of acute mitral regurgitation: effects of ventricular volume, pressure and contractility on the effective regurgitant orifice area. Circulation. 1979;60:170-176.[Abstract]
56. Sagie A, Schwammenthal E, Padial LR, Vazquez de Prada JA, Weyman AE, Levine RA. Determinants of functional tricuspid regurgitation in incomplete tricuspid valve closure: Doppler color flow study of 109 patients. J Am Coll Cardiol. 1994;24:446-453.[Abstract]
57. Grayburn PA, Wolfgang F, Omran H, Brickner ME, Lüderitz B. Multiplane transesophageal echocardiographic assessment of mitral regurgitation by Doppler color flow mapping of the vena contracta. Am J Cardiol. 1994;74:912-917.[Medline] [Order article via Infotrieve]
58.
Mele D, Vandervoort P, Palacios I, Rivera JM, Dinsmore
RE, Schwammenthal E, Marshall JE, Weyman AE, Levine RA. Proximal
jet size by Doppler color flow mapping predicts severity of mitral
regurgitation: clinical studies.
Circulation. 1995;91:746-754.
59.
Hall SA, Brickner ME, Willett DL, Irani WN, Afridi I,
Grayburn PA. Assessment of mitral regurgitation
severity by Doppler color flow mapping of the vena
contracta. Circulation. 1997;95:636-642.
60. Burch GE, De Pasquale NP, Phillips JH. The syndrome of papillary muscle dysfunction. Am Heart J. 1968;75:399-415.[Medline] [Order article via Infotrieve]
61. Levy MJ, Edwards JE. Anatomy of mitral insufficiency. Prog Cardiovasc Dis. 1962;5:119-144.[Medline] [Order article via Infotrieve]
62.
Perloff JD, Roberts WC. The mitral
apparatus: functional anatomy of mitral
regurgitation. Circulation. 1972;46:227-239.
63. Handschumacher MD, Lethor J-P, Siu SC, Mele D, Rivera JM, Picard MH, Weyman AE, Levine RA. A new integrated system for three-dimensional echocardiographic reconstruction: development and validation for ventricular volume with application in human subjects. J Am Coll Cardiol. 1993;21:743-753.[Abstract]
64. Burch GE, De Pasquale NP. Time course of tension in papillary muscles of heart. JAMA. 1965;192:701-704.
65. Arts T, Meerbaum S, Reneman R, Corday E. Stresses in the closed mitral valve: a model study. J Biomech. 1983;16:539-547.[Medline] [Order article via Infotrieve]
66. Bock RD. Multivariate Statistical Methods in Behavioral Research. New York, NY: McGraw-Hill; 1975:266-268, 422-424.
67. Morrison DF. Multivariate Statistical Methods. New York, NY: McGraw-Hill; 1976:32.
68. Gilon D, Lee M-Y, Jiang L, Otsuji Y, Karvounis H, Roy MJ, Weyman AE, Levine RA. Absence of functional mitral regurgitation (MR) despite severely reduced left ventricular function: insights into the mechanism of MR. J Am Coll Cardiol. 1996;27:115A. Abstract.
69. Bellotti G, Moraes A, Bochi E, Medeiros C, Bacal F, Esteves A, Graziosi P, Moreira LF, Cerri GG, Stolf NG. Surgical remodeling of the left ventricle in severe dilated cardiomyopathy: short-term results on cardiac mechanics. Circulation. 1996;94(suppl I):I-548. Abstract.
70. Acar C, Berrebi A, Tolan M, Chachques JC. Partial mitral homograft: a new technique for mitral valve repair. J Heart Valve Dis. 1995;4:665-668.[Medline] [Order article via Infotrieve]
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|
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|
|
R. O. Bonow, B. A. Carabello, K. Chatterjee, A. C. de Leon Jr, D. P. Faxon, M. D. Freed, W. H. Gaasch, B. W. Lytle, R. A. Nishimura, P. T. O'Gara, et al. ACC/AHA 2006 Practice Guidelines for the Management of Patients With Valvular Heart Disease: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to Revise the 1998 Guidelines for the Management of Patients With Valvular Heart Disease) Developed in Collaboration With the Society of Cardiovascular Anesthesiologists Endorsed by the Society for Cardiovascular Angiography and Interventions and the Society of Thoracic Surgeons J. Am. Coll. Cardiol., August 1, 2006; 48(3): 598 - 675. [Full Text] [PDF]
|
|
|
|
|
|
T.-T. Ton-Nu, R. A. Levine, M. D. Handschumacher, D. J. Dorer, C. Yosefy, D. Fan, L. Hua, L. Jiang, and J. Hung Geometric Determinants of Functional Tricuspid Regurgitation: Insights From 3-Dimensional Echocardiography Circulation, July 11, 2006; 114(2): 143 - 149. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D.-H. Kang, M.-J. Kim, S.-J. Kang, J.-M. Song, H. Song, M.-K. Hong, K.-J. Choi, J.-K. Song, and J.-W. Lee Mitral Valve Repair Versus Revascularization Alone in the Treatment of Ischemic Mitral Regurgitation Circulation, July 4, 2006; 114(1_suppl): I-499 - I-503. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Messas, C. Yosefy, M. Chaput, J. L. Guerrero, S. Sullivan, P. Menasche, A. Carpentier, M. Desnos, A. A. Hagege, G. J. Vlahakes, et al. Chordal Cutting Does Not Adversely Affect Left Ventricle Contractile Function Circulation, July 4, 2006; 114(1_suppl): I-524 - I-528. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Kuwahara, Y. Otsuji, Y. Iguro, T. Ueno, F. Zhu, N. Mizukami, K. Kubota, K. Nakashiki, T. Yuasa, B. Yu, et al. Mechanism of Recurrent/Persistent Ischemic/Functional Mitral Regurgitation in the Chronic Phase After Surgical Annuloplasty: Importance of Augmented Posterior Leaflet Tethering Circulation, July 4, 2006; 114(1_suppl): I-529 - I-534. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Messas, A. Bel, M. C. Morichetti, C. Carrion, M. D. Handschumacher, S. Peyrard, J. T. Vilquin, M. Desnos, P. Bruneval, A. Carpentier, et al. Autologous Myoblast Transplantation for Chronic Ischemic Mitral Regurgitation J. Am. Coll. Cardiol., May 16, 2006; 47(10): 2086 - 2093. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. H. Rogers, J. A. Macoviak, D. A. Rahdert, P. A. Takeda, I. F. Palacios, and R. I. Low Percutaneous Septal Sinus Shortening: A Novel Procedure for the Treatment of Functional Mitral Regurgitation Circulation, May 16, 2006; 113(19): 2329 - 2334. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Nomura, T. Isomura, T. Horii, H. Irie, J. Hoshino, H. Makinae, and H. Suma Efficacy of left ventricular restoration with mitral valve surgery for endstage ischemic cardiomyopathy Interactive CardioVascular and Thoracic Surgery, April 1, 2006; 5(2): 179 - 182. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P Kies, C Leclercq, G B Bleeker, C Crocq, S G Molhoek, C Poulain, L van Erven, M Bootsma, K Zeppenfeld, E E van der Wall, et al. Cardiac resynchronisation therapy in chronic atrial fibrillation: impact on left atrial size and reversal to sinus rhythm Heart, April 1, 2006; 92(4): 490 - 494. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Di Donato, P. Dabic, S. Castelvecchio, C. Santambrogio, J. Brankovic, L. Collarini, T. Joussef, A. Frigiola, G. Buckberg, L. Menicanti, et al. Left ventricular geometry in normal and post-anterior myocardial infarction patients: sphericity index and 'new' conicity index comparisons Eur. J. Cardiothorac. Surg., April 1, 2006; 29(Suppl_1): S225 - S230. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Z. Campwala, R. C. Bansal, N. Wang, A. Razzouk, and R. G. Pai Mitral regurgitation progression following isolated coronary artery bypass surgery: frequency, risk factors, and potential prevention strategies Eur. J. Cardiothorac. Surg., March 1, 2006; 29(3): 348 - 353. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Is a good perioperative echocardiographic result predictive of durability in ischemic mitral valve repair? J. Thorac. Cardiovasc. Surg., March 1, 2006; 131(3): 565 - 573.e2.
|
|
|
|
|
|
M. A. Borger, A. Alam, P. M. Murphy, T. Doenst, and T. E. David Chronic Ischemic Mitral Regurgitation: Repair, Replace or Rethink? Ann. Thorac. Surg., March 1, 2006; 81(3): 1153 - 1161. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. Porciani, R. Macioce, G. Demarchi, M. Chiostri, N. Musilli, F. Cappelli, A. Lilli, G. Ricciardi, and L. Padeletti Effects of cardiac resynchronization therapy on the mechanisms underlying functional mitral regurgitation in congestive heart failure Eur J Echocardiogr, January 1, 2006; 7(1): 31 - 39. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Fukuda, R. Grimm, J.-M. Song, T. Kihara, M. Daimon, D. A. Agler, B. L. Wilkoff, A. Natale, J. D. Thomas, and T. Shiota Electrical Conduction Disturbance Effects on Dynamic Changes of Functional Mitral Regurgitation J. Am. Coll. Cardiol., December 20, 2005; 46(12): 2270 - 2276. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Kohli, H. Wasir, S. Mittal, A. Karlekar, Y. Mehta, and N. Trehan Mitral Valve Repair for Ischemic Mitral Regurgitation in Dilated Cardiomyopathy Asian Cardiovasc Thorac Ann, September 1, 2005; 13(3): 267 - 270. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Zhu, Y. Otsuji, G. Yotsumoto, T. Yuasa, T. Ueno, B. Yu, C. Koriyama, S. Hamasaki, S. Biro, A. Kisanuki, et al. Mechanism of Persistent Ischemic Mitral Regurgitation After Annuloplasty: Importance of Augmented Posterior Mitral Leaflet Tethering Circulation, August 30, 2005; 112(9_suppl): I-396 - I-401. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Matsunaga and C. M. G. Duran Progression of Tricuspid Regurgitation After Repaired Functional Ischemic Mitral Regurgitation Circulation, August 30, 2005; 112(9_suppl): I-453 - I-457. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Levine and E. Schwammenthal Ischemic Mitral Regurgitation on the Threshold of a Solution: From Paradoxes to Unifying Concepts Circulation, August 2, 2005; 112(5): 745 - 758. [Full Text] [PDF]
|
|
|
|
|
|
P. Lancellotti, P. L. Gerard, and L. A. Pierard Long-term outcome of patients with heart failure and dynamic functional mitral regurgitation Eur. Heart J., August 1, 2005; 26(15): 1528 - 1532. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Uemura, Y. Otsuji, K. Nakashiki, S. Yoshifuku, Y. Maki, B. Yu, N. Mizukami, E. Kuwahara, S. Hamasaki, S. Biro, et al. Papillary Muscle Dysfunction Attenuates Ischemic Mitral Regurgitation in Patients With Localized Basal Inferior Left Ventricular Remodeling: Insights From Tissue Doppler Strain Imaging J. Am. Coll. Cardiol., July 5, 2005; 46(1): 113 - 119. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Barrea, S. Levasseur, K. Roman, M. Nii, J. G. Coles, W. G. Williams, and J. F. Smallhorn Three-dimensional echocardiography improves the understanding of left atrioventricular valve morphology and function in atrioventricular septal defects undergoing patch augmentation J. Thorac. Cardiovasc. Surg., April 1, 2005; 129(4): 746 - 753. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Calafiore, M. Di Mauro, M. Contini, L. Weltert, and A. Bivona Mitral valve repair in ischemic mitral regurgitation MMCTS, March 24, 2005; 2005(0324): 521. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Watanabe, Y. Ogasawara, Y. Yamaura, T. Kawamoto, E. Toyota, T. Akasaka, and K. Yoshida Quantitation of mitral valve tenting in ischemic mitral regurgitation by transthoracic real-time three-dimensional echocardiography J. Am. Coll. Cardiol., March 1, 2005; 45(5): 763 - 769. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Zamorano, L. P. de Isla, L. Oliveros, C. Almeria, J. L. Rodrigo, A. Aubele, J. Banchs, and C. Macaya Prognostic influence of mitral regurgitation prior to a first myocardial infarction Eur. Heart J., February 2, 2005; 26(4): 343 - 349. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. X. Qin, T. Shiota, H. Tsujino, G. Saracino, R. D. White, N. L. Greenberg, J. Kwan, Z. B. Popovic, D. A. Agler, W. J. Stewart, et al. Mitral annular motion as a surrogate for left ventricular ejection fraction: real-time three-dimensional echocardiography and magnetic resonance imaging studies Eur J Echocardiogr, December 1, 2004; 5(6): 407 - 415. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Delabays, X. Jeanrenaud, P.-G. Chassot, L.K. Von Segesser, and L. Kappenberger Localization and quantification of mitral valve prolapse using three-dimensional echocardiography Eur J Echocardiogr, December 1, 2004; 5(6): 422 - 429. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H J Nesser, O-A Breithardt, and B K Khandheria Established and evolving indications for cardiac resynchronisation Heart, December 1, 2004; 90(suppl_6): vi5 - vi9. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Byrne, D. M. Kaye, M. Mathis, D. G. Reuter, C. A. Alferness, and J. M. Power Percutaneous Mitral Annular Reduction Provides Continued Benefit in an Ovine Model of Dilated Cardiomyopathy Circulation, November 9, 2004; 110(19): 3088 - 3092. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Kanzaki, R. Bazaz, D. Schwartzman, K. Dohi, L. E. Sade, and J. Gorcsan III A mechanism for immediate reduction in mitral regurgitation after cardiac resynchronization therapy: Insights from mechanical activation strain mapping J. Am. Coll. Cardiol., October 19, 2004; 44(8): 1619 - 1625. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. A. Pierard and P. Lancellotti The Role of Ischemic Mitral Regurgitation in the Pathogenesis of Acute Pulmonary Edema N. Engl. J. Med., October 14, 2004; 351(16): 1627 - 1634. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Levine Dynamic Mitral Regurgitation -- More Than Meets the Eye N. Engl. J. Med., October 14, 2004; 351(16): 1681 - 1684. [Full Text] [PDF]
|
|
|
|
|
|
H.-Y. Yu, M.-Y. Su, T.-Y. Liao, H.-H. Peng, F.-Y. Lin, and W.-Y. I. Tseng Functional mitral regurgitation in chronic ischemic coronary artery disease: Analysis of geometric alterations of mitral apparatus with magnetic resonance imaging J. Thorac. Cardiovasc. Surg., October 1, 2004; 128(4): 543 - 551. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Levine, E. Messas, N. S. Nathan, and L. G. Rudski New understanding of ischemic mitral regurgitation: the marionette and its masters Eur J Echocardiogr, October 1, 2004; 5(5): 313 - 317. [Full Text] [PDF]
|
|
|
|
|
|
E. Agricola, M. Oppizzi, F. Maisano, M. De Bonis, A. F.L. Schinkel, L. Torracca, A. Margonato, G. Melisurgo, and O. Alfieri Echocardiographic classification of chronic ischemic mitral regurgitation caused by restricted motion according to tethering pattern Eur J Echocardiogr, October 1, 2004; 5(5): 326 - 334. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Hung, L. Papakostas, S. A. Tahta, B. G. Hardy, B. A. Bollen, C. M. Duran, and R. A. Levine Mechanism of Recurrent Ischemic Mitral Regurgitation After Annuloplasty: Continued LV Remodeling as a Moving Target Circulation, September 14, 2004; 110(11_suppl_1): II-85 - II-90. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Rodriguez, F. Langer, K. B. Harrington, F. A. Tibayan, M. K. Zasio, D. Liang, G. T. Daughters, N. B. Ingels, and D. C. Miller Cutting Second-Order Chords Does Not Prevent Acute Ischemic Mitral Regurgitation Circulation, September 14, 2004; 110(11_suppl_1): II-91 - II-97. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. R Brandt, J. Sperzel, H. F Pitschner, and C. W Hamm Echocardiographic assessment of mitral regurgitation in patients with heart failure Eur. Heart J. Suppl., August 1, 2004; 6(suppl_D): D25 - D28. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Franke and H. P Kuehl Regurgitant mitral valve and 3D echocardiography--meant for each other? Eur J Echocardiogr, June 1, 2004; 5(3): 159 - 161. [Full Text] [PDF]
|
|
|
|
|
|
G. G. Pellizzon, C. L. Grines, D. A. Cox, T. Stuckey, J. E. Tcheng, E. Garcia, G. Guagliumi, M. Turco, A. J. Lansky, J. J. Griffin, et al. Importance of mitral regurgitation inpatients undergoing percutaneous coronaryintervention for acute myocardial infarction: The Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) Trial J. Am. Coll. Cardiol., April 21, 2004; 43(8): 1368 - 1374. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Inoue, P. M. McCarthy, Z. B. Popovic, K. Doi, S. Schenk, H. Nemeh, Y. Ootaki, M. W. Kopcak Jr, R. Dessoffy, J. D. Thomas, et al. The Coapsys device to treat functional mitral regurgitation: In vivo long-term canine study J. Thorac. Cardiovasc. Surg., April 1, 2004; 127(4): 1068 - 1077. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. H. Yacoub and L. H. Cohn Novel Approaches to Cardiac Valve Repair: From Structure to Function: Part I Circulation, March 2, 2004; 109(8): 942 - 950. [Full Text] [PDF]
|
|
|
|
|
|
A. E. Weyman The year in echocardiography J. Am. Coll. Cardiol., January 7, 2004; 43(1): 140 - 148. [Full Text] [PDF]
|
|
|
|
|
|
R. A. Levine and J. Hung Ischemic mitral regurgitation, the dynamic lesion: clues to the cure J. Am. Coll. Cardiol., December 3, 2003; 42(11): 1929 - 1932. [Full Text] [PDF]
|
|
|
|
|
|
W. A. Zoghbi, M. Enriquez-Sarano, E. Foster, P. A. Grayburn, C. D. Kraft, R. A. Levine, P. Nihoyannopoulos, C. M. Otto, M. A. Quinones, H. Rakowski, et al. American Society of Echocardiography: recommendations for evaluation of the severity of native valvular regurgitation with two-dimensional and Doppler echocardiography : A report from the American Society of Echocardiography's Nomenclature and Standards Committee and The Task Force on Valvular Regurgitation, developed in conjunction with the American College of Cardiology Echocardiography Committee, The Cardiac Imaging Committee, Council on Clinical Cardiology, The American Heart Association, and the European Society of Cardiology Working Group on Echocardiography, represented by: Eur J Echocardiogr, December 1, 2003; 4(4): 237 - 261. [Full Text] [PDF]
|
|
|
|
|
|
J. H. Gorman III, R. C. Gorman, B. M. Jackson, Y. Enomoto, M. G. St. John-Sutton, and L. H. Edmunds Jr Annuloplasty ring selection for chronic ischemic mitral regurgitation: lessons from the ovine model Ann. Thorac. Surg., November 1, 2003; 76(5): 1556 - 1563. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Messas, B. Pouzet, B. Touchot, J. L. Guerrero, G. J. Vlahakes, M. Desnos, P. Menasche, A. Hagege, and R. A. Levine Efficacy of Chordal Cutting to Relieve Chronic Persistent Ischemic Mitral Regurgitation Circulation, September 9, 2003; 108(90101): II-111 - 115. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. A. Timek, S. L. Nielsen, D. T. Lai, F. A Tibayan, D. Liang, F. Rodriguez, G. T. Daughters, N. B. Ingels Jr, and D. C. Miller Edge-to-Edge Mitral Valve Repair Without Ring Annuloplasty for Acute Ischemic Mitral Regurgitation Circulation, September 9, 2003; 108(90101): II-122 - 127. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. A. Breithardt, A. M. Sinha, E. Schwammenthal, N. Bidaoui, K. U. Markus, A. Franke, and C. Stellbrink Acute effects of cardiac resynchronization therapy on functional mitral regurgitation in advanced systolic heart failure J. Am. Coll. Cardiol., March 5, 2003; 41(5): 765 - 770. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Kwan, T. Shiota, D. A. Agler, Z. B. Popovic, J. X. Qin, M. A. Gillinov, W. J. Stewart, D. M. Cosgrove, P. M. McCarthy, and J. D. Thomas Geometric Differences of the Mitral Apparatus Between Ischemic and Dilated Cardiomyopathy With Significant Mitral Regurgitation: Real-Time Three-Dimensional Echocardiography Study Circulation, March 4, 2003; 107(8): 1135 - 1140. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. A. Timek, D. T. Lai, F. Tibayan, D. Liang, G. T. Daughters, P. Dagum, M. K. Zasio, S. Lo, T. Hastie, N. B. Ingels Jr, et al. Ischemia in three left ventricular regions: Insights into the pathogenesis of acute ischemic mitral regurgitation J. Thorac. Cardiovasc. Surg., March 1, 2003; 125(3): 559 - 569. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Kumanohoso, Y. Otsuji, S. Yoshifuku, K. Matsukida, C. Koriyama, A. Kisanuki, S. Minagoe, R. A. Levine, and C. Tei Mechanism of higher incidence of ischemic mitral regurgitation in patients with inferior myocardial infarction: Quantitative analysis of left ventricular and mitral valve geometry in 103 patients with prior myocardial infarction J. Thorac. Cardiovasc. Surg., January 1, 2003; 125(1): 135 - 143. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. C. Gorman, J. H. Gorman III, and L. H. Edmunds Jr. Ischemic Mitral Regurgitation Card. Surg. Adult, January 1, 2003; 2(2003): 751 - 769. [Full Text]
|
|
|
|
|
|
P. M. McCarthy Does the intertrigonal distance dilate? Never say never J. Thorac. Cardiovasc. Surg., December 1, 2002; 124(6): 1078 - 1079. [Full Text]
|
|
|
|
|
|
A. C. Hueb, F. B. Jatene, L. F. P. Moreira, P. M. Pomerantzeff, E. Kallas, and S. A. de Oliveira Ventricular remodeling and mitral valve modifications in dilated cardiomyopathy: New insights from anatomic study J. Thorac. Cardiovasc. Surg., December 1, 2002; 124(6): 1216 - 1224. [Abstract] [Full Text]
|
|
|
|
|
|
J. Hung, J. L. Guerrero, M. D. Handschumacher, G. Supple, S. Sullivan, and R. A. Levine Reverse Ventricular Remodeling Reduces Ischemic Mitral Regurgitation: Echo-Guided Device Application in the Beating Heart Circulation, November 12, 2002; 106(20): 2594 - 2600. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. T. Lai, T. A. Timek, F. A. Tibayan, G. R. Green, G. T. Daughters, D. Liang, N. B. Ingels Jr, and D. C. Miller The effects of mitral annuloplasty rings on mitral valve complex 3-D geometry during acute left ventricular ischemia Eur. J. Cardiothorac. Surg., November 1, 2002; 22(5): 808 - 816. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Otsuji, T. Kumanohoso, S. Yoshifuku, K. Matsukida, C. Koriyama, A. Kisanuki, S. Minagoe, R. A. Levine, and C. Tei Isolated annular dilation does not usually cause important functional mitral regurgitation: Comparison between patients with lone atrial fibrillation and those with idiopathic or ischemic cardiomyopathy J. Am. Coll. Cardiol., May 15, 2002; 39(10): 1651 - 1656. [Abstract] [Full Text] [PDF]
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