Download Left ventricular diastolic collapse in regional left heart

3ACC Vol, 22, No . 3
September 1993 :", 7-13
Lefft Ventr1c . -,Aar Diastolic Colla
Cardiac
907
R
en .ear
An Experimental Echocardiographic and Hemodynamic Study
STEVEN L . SCHWARTZ, IM D, FACC, NATESA G . PANDIAN, MD, FACC, QI-LING CAO, MD,
TSUALIE11 HSU, MD, MARK ARONOVITZ, BA, JAMES DIEHL, MD, FACC, FACS
Boston . Massachusetts
Objectives . This study was designed to describe the hemodyy
namic abnormalities associated with the appearance of left ventricular diastolic collapse in the setting of regional left heart
cardiac himponade.
Background. Cardiac tamponade after heart surgery is frequently associated with localized pericardial effusion . P34hough
right ventricular diastolic collapse and right atrial collapse are
reliabe cbradiographicfndigs npatienswithcrumfernl
tial pericardial effusion and tamponade, they are often not present
in postoperative patients with localized pericardial effusion and
regional left heart tamponade . Left ventricular diastolic collapse
has been described in such patients, but the degree of hemodynamic alteration that exists with this finding is not known .
Methods . Acute regional left heart tamponade was produced 14
times in seven spontaneously breathing anesthetized dogs by
infusing fluid into an isolated compartment created in the pericardial space adjacent to the left ventricular free wall . Continuous
echocardlographic imaging and hemodynamic monitoring of left
ventricular, systemic arterial, right atrial, pulmonary capillary
wedge and pericardial pressures were performed . Measurements
at baseline were compared with those made at the onset of left
ventricular diastolic collapse and at decomtwnsated taimponade .
Results . Left ventricular diastolic collapse was noted in all 14
episodes of regional tamponade . It occurred when pressure in the
left pericardial compartment exceeded ieft ventricular diastolic
pressure by 3.0 ± 1 .9 aarn 11g . At the onset of left ventricular
diastolic collapse, cardiac output and mean arterial pressure were
significantly reduced from the control value (p < 0 .05) . Systo-lic
hvpnfc .asion was noted only twice at this stage, respiratory variation in systolic pressure >10 tam Hg only once . The appearance
of this sign was also associated with elevated left heart falling
pressures .
Conclusions . Left ventricular diastolic collapse is a reliable sign
of regional left ventricular tamponade and is associated with a
reduction in cardiac output . This echocardiographic finding usually occurs before the development of arterial hypotension and
pulses paradoxus . Thus, left ventricular diastolic collapse is
potentially more reliable than hypotension or pulses paradomus in
the diagnosis of regional left ventricular tamponade .
(J Am Coll Cardiol 1993 ;22:907-13)
Pericardial effusion is a frequent event after cardiac surgery,
occurring in -85% of pzlients (1) . Fortunately, it is usually
uncomplicated and reso' les spontaneously . Cardiac tam-
cardiac tamponade (4-9) . However, fluid collections in
ponade may occur in these patients, with a reported inci-
of patients with localized effusion and cardiac tamponade are
dence varying between 0 .1% and 8 .8% (1,2) . For the initial
often atypical . Left ventricular diastolic collapse, an inward
displacement of the posterior wall of the left ventricle in
diastole, has been described as a market - of cardiac tampon-
reported cases of postoperative tamponade, the mortality
rate was 43% (3) . Early detection of tamponade is potentially
life-saving in patients with pericardial effusion . Echocardiography has been shown to be useful in the evaluation of
postoperative patients are often posterior to the left ventricle
(10-13) . As a result, clinical and echocardiographic features
ade in patients with localized hematoma or effusion
(10,11,14-17) . Such observations were made retrospec-
patients with effusion ; demonstration of right atrial collapse
tively ; therefore, the degree of hemodynamic derangement
or right ventricular diastolic collapse is a reliable indicator of
associated with the appearance of this sign is not known .
From the Departments of Medicine and Surgery, New England Medical
Center, Tufts University School of Medicine, Boston, Massachusetts . This
study was presented at the 64th Annual Scientific Sessions of the American
Heart Association, November 1991, Anaheim, California .
Manuscript received November 5, 1992 ; revised manuscript received
February 19, 1993, accepted March 10, 1993 .
Address fo[_ggmqW_ondente :: Steven L . Schwartz, MD, New England
Medical Center, 750 Washington Street, Box 70, Boston, Massachusetts
02111 .
The hemodynamic abnormalities produced by regional left
heart compression have been described by Fowler et al . (18),
but the relation between the hemodynamic derangements
and the echocardiographic features of regional left heart
tamponade has not been demonstrated . We designed this
study to determine the relation between the echocardiographic sign of left ventricular diastolic collapse and the
hemodynamic alterations associated with regional left ventricular tamponade .
©1 993 by the American College of Cardiology
0735-107/9366,00
908
SCHWARTZ ET AL .
LEFT VENTRICULAR DIASTOLIC COLLAPSE IN REGIONAL TAMPONADE
~~- Catheter
16V
PDA
it re 1 . Schematic diagram of experimental preparation . The
balloon catheter used for creation of the regional pericardial effusion
is placed in the pericardial space adjacent to the posterior wall of the
left ventricle (LV) . The pericardium is loosely sewn around the
balloon . An additional pigtail catheter s placed in the pericardial
space anterior to the right ventricle (RV) . PDA - posterior descending coronary artery .
Methods
Preparation . An animal model of acute regional cardiac
tamponade was used . Nine male or female mongrel dogs
(13 to 20 kg) were anesthetized with sodium pentobarbital
(25 mglkg body weight intravenously), intubated and ventilated on a Harvard volume cycle respirator. Fluid-filled
catheters were advanced percutaneously into the left ventricle and right atrium and connected to pressure transducers .
A balloon-tipped thermodilution catheter was placed in the
pulmonary artery . Catheter position was confirmed using
hemodynamic tracings and fluoroscopy . Arterial blood pressure was measured using an 8F sheath in the left femoral
artery . The electrocardiogram was continuously monitored
throughout the experiment .
A left lateral thoracotomy was performed . A small incision was made in the pericardium laterally, and a customdesigned 7F catheter with a 3 x 4-cm latex balloon at the
distal end was inserted into the pericardial space posterior to
the left ventricle and held in place with a purse-string suture
(Fig . 1). This cathew was used for pressure measurement
and infusion of saline solution . Balloon position was confirmed to be adjacent to the left ventricle with epicardial
echocardiography . The pericardium was then sewn to the
myocardium around the balloon . This created two pericardial compartments, one outside the left ventricle, which
would be filled with fluid to create regional effusion and
tamponade, and one outside the right ventricle . A 7F pigtail
catheter was placed in the pericardial space anterior to the
right ventricle to monitor pressure in this compartment . The
chest was closed and the pricurnothorax was reduced with a
chest tube placed to underwater seal.
ExPerimatal Protocd- Intravenous sedation was adjusted to allow the dogs to be weaned from the ventilator .
The protocol was carried out with the dogs breathing spontaneously_ Heart rate and the following pressures were
JACC Vol. 22, No. 3
September 1993:907-13
recorded at baseline : systemic arterial, left ventricular,
pulmonary capillary wedge, right atrial, left pericardial (measured using the balloon catheter) and right pericardial .
Cardiac output was measured by the thermodilution method .
Echocardiographic imaging with a Hewlett-Packard Sonos
1000 imaging system was performed at baseline and continuously throughout the study from the right parasternal
region . Long- and short-axis images of the left ventricle were
obtained.
Normal saline solution was infused into the left pericardial compartment at 5-ml intervals . Repeat hemodynamic
and echocardiographic measurements were obtained at each
period . The onset of left ventricular diastolic collapse,
defined as a discrete, transient, inward motion of the left
ventricular free wall adjacent to the pericardial effusion in
diastole, was noted (Fig . 2) . The infusion was terminated
when the mean arterial pressure was reduced to 75% of that
in the control state, a condition defined as decompensated
cardiac tamponade (19) .
The fluid was removed and the dogs were allowed to
recover for 30 min . The protocol was repeated . The animals
were killed with an anesthetic overdose after completion of
the experiment. Balloon position in the pericardium was
visually confirmed . The balloon was removed from the
pericardium, attached to a pressure transducer and filled
with saline solution as in the protocol to determine its
pressure-volume characteristics .
The experimental protocol was approved by the New
England Medical Center Animal Research Committee . The
study conforms to the "Position of the American Heart
A, sociation of Research Animal Use" adopted by that
Association in November 1984 .
Data analysis. The following hemodynamic measurements were recorded at each stage : heart rate, arterial
pressure, respiratory variation in systolic pressure or pulsus
paradoxus, left ventricular diastolic pressure, pulmonary
capillary wedge pressure, right atrial pressure and pressure
in the left and right pericardial compartments . Cardiac
output was determined by the average of at least three
measurements using a thermistor-tipped catheter . Stroke
volume was calculated by dividing the cardiac output by the
heart rate. From the echocardiographic images, left ventricular cavity area was measured at end-diastole in the shortaxis view off-line using the analysis package contained
within the imaging system . Images were viewed by two
observers unaware of the experimental protocol to determine the interobserver variability for the presence of left
ventricular diastolic collapse . Data obtained at baseline and
at the onset of left ventricular diastolic collapse and of
decompensated tamponade were compared using repeated
measures analysis of variance testing with use of a commercially available statistical program (Statview II, Abacus
Concepts Inc .) . The Fisher least-squaree difference test was
used to determine differences between groups . All data are
presented as mean value t SD . Data were considered
significantly different if p was < 105 .
JACC Vol . 22, No . 3
September 1993 : 907-13
SCHWARTZ ET AL .
LEFTVEN'._UCULAR DIASTOLIC COLLAPSE !N 14EGIONAL TAMPONADE
Figure i . Diastolic two-dimensional
echocardiographic frames taken from
one dog at various points during the
experimental protocol . "Fop left, Baseline
image, no effusion is present . Top right,
Pericardial effusion without significant
tamponade . At this point ; the left mntricle maintains its circular shape . Bottom
left, At the onset of left ventricular diastolic collapse, the pressure within the
localized effusion is now greater than
that in the left ventricle (LV) in diastole,
and left ventricular diastolic collapse is
noted (arrow) . Bottom right, Image recorded at the stage of "decompensated
tamponade ." Continued infusion of fluid
creates a larger effusion with a more
pronounced deformation of the left ventricular posterior wall .
Results
Hemodynamic: ineasuremepas. Regional cardiac tamponade was produced 14 times in seven dogs (two dogs died
before completing the rmtocol) . Left ventricular diastolic
collapse was noted in all 14 episodes and occurred when
pressure in the left pericardial compartment exceeded left
ventricular diastolic pressure (Fig . 3) . In 13 of 14 episodes
the appearance of left ventricular diastolic collapse preceded
the stage of decompensated tamponade ; in I episode the
echocardiographic sign appeared simultaneously with the
defined hemodynamic decompensation (mean arterial pressure :575% of the control value) .
The hemodynamic data obtained at baseline and at the
onset of left ventricular diastolic collapse and of decompensated cardiac tamponade are summarized in Table 1 . At the
onset of left ventricular diastolic collapse, cardiac output
was reduced 20 ± 4 .3% from baseline (p < 0 .05) . Although
both the mean and systolic arterial pressures were also
significantly reduced, they were both in the normal range .
Systolic hypotension was noted only twice at this stage . The
increase in respiratory variation in systolic pressure did not
achieve significance ; there was only one instance in which it
was > 10 mm Hg . Both left ventricular diastolic pressure and
pulmonary capillary wedge pressure had increased significantly, whereas right atria( pressure was unchanged .
There was a further reduction in cardiac output and blood
pressure with continued infusion of fluid into the pericardial
space. Although the average systolic arterial pressure at this
stage was 80 ± 20 mm Hg, hypotension was present in only
8 of 14 cases . Respiratory variation in systolic pressure
increased to 8 .5 mm Hg but was > 10 mm Hg in just three
episodes . As expected, there was a further increase in left
ventricular diastolic pressure . Only at the final stage of
decompensated tamponade did the right atrial pressure exhibit a significant increase from baseline .
Figure 3 . Hemodynamic recordings from the left ventricle and left
pericardial compartment from one dog. Left, Pericardial effusion
without left ventricular diastolic collapse . Left ventricular pressure
(LV) was greater than pericardial pressure (P) throughout the
cardiac cycle . Right, Pericardial volume and pressure have increased . Left ventricular diastolic pressure has also increased but is
now less than pericardial pressure . Left ventricular diastolic collapse was noted on the echocardiogram .
LV
LY i
910
JACC Vol . 22, No . 3
SCHWAIR" ET AL
LEFT VENTRICULAR DIASTOLIC COLLAPSE IN REGIONAL TAMPONADE
September 1993 :907-13
Table 1 . Hemodynatnic Data During Production of Regional Cardiac Tamponade in Seven Dogs
Pressures (mm Hg)
Mean arterial
Systolic arterial
Resp. variation in systolic pressure
LV diastolic
PCWP
Right atrial
Pericardial
Transmural pressure gradient
Pericardial volume (ml)
Cardiac output (liters/mW
Stroke volume (ml)
Baseline
LV Diastolic
Collapse
94 t 19
116 t 23
5 .4 ± 4 .1
11 ± 4
It* 5
13 4 .5
0 .9 2 .1
it 3 .8
0
2 .9 ± 0 .91
21 ± 5 .9
82 t 19*
104 t 24*
7.2 ± 2 .1
17 ± 7 .1*
.9*
14±4
10 ± 4 .3
21 .4 ± 10 .0
-3 .0 ± 1 .9
19 .6 ± 4.6
2.3 ± 0,59*
16 ± 4.0*
Decompensated
Cardiac
Tamponade
63
81
8 .5
22
16
12
±
±
±
±
16t
20t
3.5*
10t
it*
4.lt
18 14
1 .6 ± 0 .47t
12 ± 3 .7t
*p < 0,05 versus baseline . tp < 0.05 versus baseline and left ventricular diastolic collapse . tAt the volumes
.
required to produce left ventricular diastolic collapse, the balloon itself exerted tin effect on huraliericardial pressure
At the higher volumes required for decompensated tamponade, "pericardial" pressure was a reflection of pressure
exerted by the pericardium and the balloon in >50% of the cases, therefore, intrapericardial pressure and transmural
pressure gradient at this stage could not be accurately measured . Values are expressed as mean value ± SD . LV
left ventricular ; PCWP - pulmonary capillary wedge pressure ; Resp . = respiratory .
Pressure measurement in the right and left pericardial
compartments demonstrated that the two were isolated . The
pressures were no different from each other at baseline . At
the appearance of left ventricular diastolic collapse, the
mean pressure was 21 ± 10 mm Hg in the left pericardial
compartment but only 3 .5 ± 3 .5 mm Hg (p < 0 .05) in the
right pericardial compartment .
Ech=rd4mphlc measurements . As already stated, left
ventricular diastolic collapse was noted in every episode of
tamponade produced and was observed when the pressure in
the left pericardial compartment exceeded that of the left
ventricle. An example of the changes in the appearance of
the left ventricle as pericardial volume increases is -11ustrated in Figure 3 . At baseline, the left ventricle appears
normal . A small volume of pericardial fluid does not change
the ventricular shape, Once pericardial pressure is greater
than left ventricular pressure, an inward concavity of the
posterior wall adjacent to the effusion (left ventricular diastolic collapse) occurs . Initially, this finding is noted within
the one half to three fourths of diastole . At this stage, mean
left ventricular end-diastolic cavity area had decreased from
the control value of 8 .9 ± 2 .0 cm2 to 6 .6 ± 1 .4 cm2 (p <
0.05), an 11% reduction. As more fluid is added to the
pericardial space, the deformation of the left ventricular wall
is more pronounced and lasts throughout diastole . Cavity
area at end-diastole was further reduced at the stage of
decompensated bapmade to 5,3 ± It cm'- (p < 0 .05 vs .
bw eline and left ventricular diastolic collapse) .
In 13 of 14 instances of left ventricular tamponade, there
was agreement between the two observers regarding the
appeanuice of left ventricular diastolic collapse . The sole
disagreement was resolved by consensus .
Discussion
The present study demonstrates that left ventricular
diastolic collapse is a reliable indicator of regional left
ventricular tamponade, occurs when pericardial pressure is
greater than left ventricular pressure in diastole and is
associated with a significant reduction in cardiac output .
Although arterial pressure is lower than observed at baseline, it is usually within the normal range . These observations imply that in regional tamponade, left ventricular
diastolic collapse is an earlier marker than clinical signs of
tamponade of a hemodynamically significant effusion .
In the typical situation in which cardiac tamponade is
caused by circumferential effusion, an increase in pericardial
fluid volume and pressure is associated with a gradual
increase in right heart filling pressures and a decrease in
cardiac output (20). As pericardial pressure continues to
increase, it transiently exceeds right ventricular diastolic
pressure, resulting in an inward motion of the right ventricular wall known as right ventricular diastolic collapse (8) . In
both experimental and clinical studies (7,19), the onset of
right ventricular diastolic collapse has been associated with
a significant reduction in cardiac output without substantial
changes in blood pressure . It has been hypothesized (19) that
the left ventricle does not demonstrate this motion because
of its greater thickness md its symmetric shape .
However, when the fluid collection is loculated posteriorly such as in the postoperative patient, collapse of these
chambers is not observed on the echocardiogram . The
increased volume and pressure within the loculated effusion
have little, if any, direct effect on right atriai pressure as
demonstrated in this study and in the model of left heart
tamponade described by Fowler et at . (18) . This increased
JACC Vol . 22, No . 3
September 1993 :907-13
SCHWARTZ ET AL .
LEFT VENTRICULAR DIASTOLIC COLLAPSE IN REGIONAL TAMPONADE
pressure is transmitted across the adjacent left ventricular
wall resulting in higher diastolic pressure, reduced enddiastolic volume and reduced stroke volume . Eventually, as
in circumferential effusions, pressure within the pericardiai
compartment transiently exceeds that of the left ventricle
itself, and the left ventricular wall is then shifted toward
the lower pressure ventricular cavity . As the situation
progresses, there is a continued increase in pericardial and
left ventricular pressure, together with a more pronounced
deformation of the left ventricular wall and even further
reductions in cardiac output and arterial pressure . Right
atria] pressure is increased at this later stage, possibly more
as a backward reflection of elevated left heart filling pressures than of localized compression .
Previous studies of regional damponade . Prior experimental evidence has suggested that right heart compression
is more important than left heart compression in cardiac
tamponade (18,21,22) . Initial studies concluded that reduction in cardiac output is primarily the result of right heart
(21) and atrial (22) compression. In contrast, Carey et al . (23)
reported a significant redaction in both arterial pressure
and cardiac output with localized tamponade of the left
ventricle alone . In a study comparing right heart tamponade,
left heart tamponade and combined tamponade, Fowler
et al . (18) reported that left heart tamponade did cause a
reduction in cardiac output, but the hemodynamic alterations of right heart tamponade were more dramatic . However, the most marked hemodynamic disturbances were
observed in combined right and left heart tamponade . This
finding implies that compression of all the cardiac chambers
conb*Aes to the hemodynamic abnormalities in cardiac
tamponade .
The clinical occurrence of regional left heart tamponade
after cardiac surgery has previously been reported
(2,10,11,14-17,24) . Paradoxic motion and compression of
the posterior wall of the left ventricle have been observed in
patients with posterior effusion (10,11,14-17) . Left ventricular diastolic collapse has also been noted in a patient
with a circumferential effusion and tamponade who had
severe pulmonary hypertension (25) . In the largest published series to date, Chuttani et al . (14) reported on 15
patients with clinical evidence of tamponade and loculated
effusion after cardiac surgery ; all exhibited left ventricular
diastolic collapse . Thus, not only is regional tamponade
clinically important, but the echocardiographic marker of
this event, left ventricular diastolic collapse, appears to
reliably indicate the presence of a hemodynamically significant effusion .
INdsus paradoxes in regional tamponalle . One finding in
this study was the low magnitude of respiratory variation in
systolic pressure despite a reduction in cardiac output and
arterial pressure . This is consistent with the prior observation that right ventricular diastolic collapse is a more reliable
sign of cardiac tamponade than is pulsus paradoxus (26) .
One criterion necessary for pulsus parW!UXLS to occur is that
both ventricles must be filling against a common stiffness
(27) . Total cardiac voloinneexpansiol must be limited by the
pericardial effusion ; therefore, any increase in right ventricular volume with inspiration impedes lei't ventricular filling .
In our model, the absence of pericardial fluid annteriorly
allewed for the right heart chambers to freely expand without interfering with left ventricular filling, so the relative
absence of pulsus paradoxus is not surprising . This observation is consistent with much of the clinical experience of
patients with loculated effusion and tamponade (2,11,15,24) .
In those studies, 8 of the 10 patients studied had clinical
evidence of tamponade without pulsus paradoxus . In contrast, 9 of the 15 patients described by Chuttani et al . (14)
had a pulsus > 10 mm Hg . Still, the majority of patients with
effusion loculated posteriorly resulting in cardiac tamponade
did not demonstrate a significant pulsus paradoxus . One
possible difference between regional tamponade in postoperative patients arid our medel is the frequent occurrence of
adhesions around the right atrium and right ventricle in
patients, which may limit the expansion of these chambers .
In the presence of adhesions and posterior pericardial effa&W it is conceivable that in some patients, an inspiratory
increase in right ventricular volume expansion does impinge
on left ventricular filling, resulting in pulsus paradoxus .
Critique of the study. Acute regional tamponade was
produced in an animal preparation and therefore does not
precisely parallel regional tamponade in patients . Although
allowed to breathe spontaneously, the animals were anesthetized, which may have altered the hemodynamic state as
well as the depth and rate of respiration . As inspiratory
augmentation of right ventricular volume is a prerequisite for
pulsus paradoxus (28), lack of sufficient changes in right
ventricular volume with respiration could diminish the observed frequency of pulsus paradoxus .
By design, we produced tamponade of the left ventricle
only, whereas some patients with loculated effusion have
fluid around other cardiac chambers as well . Thus, the
relation of left ventricular diastolic collapse to other findings
such as left atrial collapse was not explored. The presence or
absence of previously described respiratory variations in
flow velocities using spectral Doppler analysis (29-31) was
not evaluated as part of this study .
Regional tamponade was produced by inserting a balloon
in the pericardial space . This was done to ensuree that the
compartment was free of leakage . By measuring pressure in
the pericardium anterior to the right ventricle, we were able
to determine that the increased pericardial pressure was
truly a local effect . One cannot comment on whether a
localized effusion produced with a balloon catheter behaves in the same manner as one lined by pericardium, clots
and adhesions . However, the hemodynamic conditions of
the regional tamponade in this model-elevation of left
ventricular diastolic pressure and pulmonary capillary
wedge pressure in parallel with increasing pericardial pressure that was associated with reduced cardiac output-are
evidence that tamponade was truly produced . The 2001o
reduction in cardiac output that accompanied the left
912
SCHWARTZ ET AL .
LEFT VENTRICULAR DIASTOLIC COLLAPSE IN REGIONAL TAMPONADE
ventricular diastolic collapse we observed compares well
with the previously reported 21% decrement in output that
accompanied right ventricular diastolic collapse in circumferential effusion (19).
When interpreting the result3 of this study, one also must
consider that the animals studied were otherwise normal,
which is not always the case in patients undergoing cardiac
surgery . The presence of cardiac pathologic findings may
alter left ventricular diastolic pressure . Prior experimental
and clinical experience with cardiac tamponade caused by
circumferential effusion in the setting of elevated right heart
filling pressures has shown that the appearance of right
ventricular diastolic collapse might be delayed or absent
despite significant hemodynamic alteration (19,32--35) . It is
possible, therefore, that the relation between left ventricular
diastolic collapse and the hemodynamic abnormalities described in this study would not apply if the diastolic properties of the left ventricle were altered at baseline . Preliminary
data suggest that the appearance of left ventricular diastolic
collapse is delayed when left ventricular diastolic pressure is
abruptly elevated by volume expansion (36) . Further study
of regional tamponade in the presence of preexisting cardiac
abnormalities is required .
pike
CI
s. Assessment of the patient with localized pericardial effusion is frequently difficult as the
clinical and echocardiographic features of tamponade may
not be present . If, in such a patient, left ventricular diastolic
collapse is evident on the echocardiogram, it is highly likely
that an important reduction in cardiac output is present and
that drainage of the effusion should be considered . The
absence of left ventricular diastolic collapse, especially in a
patient with preexisting ventricular dysfunction, does not
exclude the diagnosis of cardiac tamponade,
References
1 . Weitzman LB, Tinker WP, Kronzon 1, Cohen ML, Glassman E, Spencer
FC. The incidence and natural history of pericardial effusion after cardiac
surgery-an echocard' ie study . Circulation 1984;69:506-11 .
2. Jones MR, Vine DI. Atlas M, Todd EP. Late isolated left ventricular
tamponade : clinical, hemodynamic, and echocardiographic manifestations of a previously unreported postoperative complication . J Thorac
Cardiovasc Surg 1979;77:142-6 .
3, Merrill W, Donahoo JS, Bromley RK, Taylor D . Late cardiac tamponade :
a potentially lethal complication of open-heart surgery. J Thorac Ca njicvase Surg 1976;72;929-32.
4 . Armstrong WIT, Schilt BF, Helper DJ, Dillon JC, Feigenbaum H . Diastolic collapse of the right ventricle with cardiac tamponade : an echocardi
is study. Circulation 1 2 ;65 :1491-6.
5, Guam LD, Guyer DE, Gibson TC, King ME, Marshall JE, Weyman AE .
Hydrodynamic compression of the right atrium : a new echocardiogtaphic
sign of cardiac tamponade . Circulation 1 3 ;68:294-301 .
6 . Kronzon I, Cohen ML, Winer HE . Diastolic atrial compression : a
sensitive eo hic sign of cardiac tamponade . J Am Coll Cardiol
1983 ;2:770 5 .
7 . Singh S, Wann LS, Schuchard GH, et al . Right ventricular and right atriat
colliapso in patients with cardiac tamponade-a combined echocardioitemodyna„m1c study, Circulation 1 ,70 :%6-71 .
8. i 'n RD, i NG, Funai JT, et al . Sensitivity of right atrial collapse
and right ventricular diastolic collapse in the diagnosis of graded cardiac
tam
. Am I Nocinvasive Cardiol 1987;1 :73-80.
JACC Vol. 22, No. 3
September 1993:907-13
9. Engel PJ, Hon H, Fowler NO, Plummer S . Echocardiographic study of
right ventricular wall motion in cardiac tamponade. Am J Cardiol 1982 ;
50 :1018-21 .
10. Gondi B, Nanda NC . Two-dimensional echocardiographic diagnosis of
mediastinal hematoma causing cardiac tamponade . Am J Cardiol 1984 ;53 :
974-6 .
11 . D'Cruz IA, Kensey K, Campbell C, Replogle R. Jain M. Two dimensional
echocardiography in cardiac tamponade occurring after cardiac surgery .
J Am Coll Cardiol 1985 ;5 :1250-2 .
12. Fyke FE III, Tancredi RG, Shub C, Julsrud PR, Sheedy PF 11 . Detection
of intrapericardial hematoma after op=,n heart surgery : the roles of
echocardiography and computed tomography . J Am Coil Cardiol 1985 ;51 :
14%-9.
13 . Kronzon 1, Cohen ML, Winer HE . Cardiac tamponade by loculated
p :riu rdial hemotoma: limitations of M-mode echocardiography . J Am
Coli Cardiol 1983 ;1 :913-5 .
14 . Chuttani K, Pattdian NG, Moltanty PK, et al . Left ventricular diastolic
collapse: an echocardiographic sign of regional cardiac tamponade . Circulation 1991 ;83 :1999-2006,
15 . Steele RL, Perez JE . Left ventricular diastolic collapse provoking cardiac
tamponade . Echocardiography 1986 ;3 :149-50 .
16 . D'Cruz IA . Kleinman D . Extracardiac causes of paradoxical motion of
the left ventricular wall . Am Heart J 1988 ;115:473-5 .
17, Conrad SA, Byrnes TJ . Diastolic collapse of the left and right ventricles
in cardiac tamponade. Am Heart J 1988;115 :475-8 .
18 . Fowler NO, Gable M, Buncher CR . Cardiac tamponade : a comparison of
right versus left heart compression . J Am Coll Cardiol 1988 ;12 :187-93 .
19 . Leimgruber PP, Klopfenstein HS, Wann SL, Brooks HL . The hemodynamic derangement associated with :fight ventricular diastolic collapse in
cardiac tamponade : an experimental echocardiographic study . Circulation 1983 ;68:612-20.
20. Reddy PS, Curtiss El . Cardiac tamponade . Cardiol Clin 1990 ;8:627-38.
21 . Ditchey R, Engler R, LeWinter M, et al . The role of the rig'..a hart in
acute cardiac tamponade in dogs . Citi Res 1981 ;48 :701-10.
22. Fowler NO, Gable M . The hetnodynamic effects of cardiac tamponade :
mainly the result of atria!, not ventricular, compression. Circulation
1985 ;71 :154-7.
23 . Carey JS, Yao ST, Kho LK, Tasche C, Shoemaker WC . Cardiovascular
responses to acute hemopericardium, compression by ballo,n tamponade, and acute coronary artery occlusion . J Thorac Cardiovasc Surg
1967 ;54 :65-80.
24, Hsu TL, Chen CC, Hsiung MC, Yu TJ, Chiang BN . Paradoxical motion
of left ventricular free wall in cardiac tamponade . Am Heart J 1986;111 :
807-8 .
25 . Frey MJ, Berko B, Palevsky H, Hirshfeld JW, Herrmann HC . Recognition of cardiac tamponade in the presence of severe pulmonary hypertension. Ann Intern Mod 1989;111 :615-7.
26 . Singh S, Wann LS, Klopfenstein HS, Hartz A, Brooks HL . Usefulness of
right ventricular diastolic collapse in diagnosing cardiac tamponade and
comparison of pulsus paradoxus . Am J Cardiol 1986 ;57:652-6 .
27 . Reddy PS, Curtiss El, O'Toole JD, Shaver JA . Cardiac tamponade :
hemodynamic observations in man . Circulation 1978 ;58:265-72 .
28 . Shabetni R, Fowler NO, Guntheroth WG. The hemodynamics of cardiac
tamponade and constrictive pericarditis . Am J Cardiol 1970;26:480-9 .
29 . Pandian NG, Rifkin RD, Wang SS . Flow velocity paradoxus-a Doppler
echocardiographic sign of cardiac tamponade: exaggerated respiratory
variation in pulmonary and aortic blood flow velocities (abstr). Circulation 1984;70(suppl I) :II-381 .
30. Leman ED, Levine MJ, Come PC . Doppler echocardiography in cardiac
tamponade : exaggerated respiratory variation in transvalvular blood flow
velocity integrals. J Am Coll Cardiol 1988 ;11 .572-8 .
31 . Appleton CP. Hatle LK, Popp RL. Ca iliac tamponade and pericardial
effusion : respiratory variation in transvalvular flow velocities studied by
Doppler echocardiography . J Am Coll Cardiol 1988 ;11 :1020-30.
32. Klopfenstein HS, Cogswell TL, Bernath GA, et al . Alterations in intravascular volume affect the relation between right ventricular diastolic
collapse and the hemodynamic severity of cardiac tamponade . J Am Coll
Cardiol 1985 ;6:1057-63.
33 . Cogswell TL, Bernath GA, Wann LS, Hoffman RG, Brooks HL,
Klopfenstein HS . Effects of intravascular volume state on the value of
JACC Vol . 22, No . 3
September 1993 :907-13
SCHWARTZ ET AL .
LEFI VENTRICULAR DIASTOLIC COLLAPSE IN REGIONAL TAMPON
E
pulsus paradoxes and right ventricular diastolic collapse in predicting
cardiac tamponade . Circulation 1985 ;72 :1076-80.
34 . Cogswell TL, Bernath GA, Keelan MH Jr, Mann LS, 151opfenstewn HS .
The shift in the relationship between intrapericardia4 fluid pressure and
volume induced by acute left ventricular pressure overload during cardiac
iatuponadc . Circulation 19W,74 .173-80.
913
35 . Hoit KID, Fowler NO . Influence of acute right ventricular dysfunct ~vu on
cardiac tamponade . J Am Coil Cardiol 3991 ;18 :!787-93 .
36 . Schwartz S . Cap QL, ILcu IL, Aroeovitz M, Pandian N . Appearance of
left ventricular diastolic collapse is delayed when regional cardia=c lamponade occurs in hypervolemic conditions (abs(r) . Circulation 1992 ;
RNWO 0103 .