Hemodynamics in off-pump surgery: normal versus compromised preoperative left ventricular function.
ABSTRACT Off-pump coronary surgery (OPCABG), avoiding cardiopulmonary bypass and cardioplegic arrest, seems to be a better choice in patients with poor baseline cardiac function. Since cardiocirculatory collapse could be induced by heart displacement in this group of patients at high risk, a greater pathophysiologic understanding of the hemodynamic derangements occurring in such patients is needed.
Twenty-eight elective OPCABG patients were evaluated for hemodynamic changes induced by heart displacement, using arterial thermodilution to measure cardiac output and global end-diastolic volume. Hemodynamic parameters were recorded: at baseline; during proper exposure and stabilization of each vessel; and at the end of surgery. Patients were divided into two groups, according to baseline ejection fraction (EF): group A (EF>30%; N=16), group B (EF< or =30%; N=12).
Heart displacement induced a significant drop in the cardiac and stroke index, with a lesser decrease of mean arterial pressure because of raised systemic vascular resistance. Preload, measured as global end diastolic volume, significantly decreased in group A, while it remained unchanged or increased in group B. Linear regression between the preload index and left ventricular stroke work was significant only in group A.
Patients with poor baseline cardiac function can well tolerate OPCABG. However, the pathophysiologic modifications underlying the hemodynamic changes are different compared to those in patients with good preoperative cardiac performance.
- SourceAvailable from: Joseph H Lee[show abstract] [hide abstract]
ABSTRACT: Objectives: Hemodynamic derangement during displacement of beating heart in off-pump coronary artery bypass graft (OPCAB) surgery might be related with right ventricular (RV) dysfunction. We evaluated RV function and hemodynamic alterations using a thermodilution pulmonary artery catheter. Methods: The study included 30 patients undergoing OPCAB, using single pericardial suture and tissue stabilizer. A thermodilution pulmonary artery catheter for continuous monitoring of the cardiac output (CO), right ventricular ejection fraction (RVEF) and RV volume was inserted before anesthesia. The hemodynamic variables were measured after the induction of anesthesia, 5 min after the heart was positioned for each coronary anastomosis and after the sternum was closed. Results: There was no significant change in the RVEF and cardiac index during anastomosis of the left anterior descending artery and right coronary artery. However, the significantly reduced RVEF accompanied by an increase in RV afterload and decrease in the CO was observed during anastomosis of the obtuse marginal (OM) artery. RV volumes did not significantly change during anastomoses, though the right atrial pressure increased during anastomoses of all coronary arteries. Conclusions: The displacement of beating heart for positioning during anastomosis of the graft to OM artery caused significant derangement of RV function and decrease in CO. A thermodilution catheter continuously measuring the CO and RVEF was useful to monitor the change in RV function and volume during OPCAB. q 2004 Elsevier B.V. All rights reserved.European Journal of Cardio-Thoracic Surgery 05/2004; 25(4). · 2.67 Impact Factor
- Intensive Care Medicine 02/1992; 18(3):137-8. · 5.26 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: In off-pump coronary surgery, exposure of posterior vessels via sternotomy causes deterioration of cardiac function. Changes in ventricular geometry, valve competence, and hemodynamics after retraction of the beating heart were studied. Subsequently, the modifying effect of right or left heart bypass was investigated. In six 80-kg pigs, an ultrasound probe was attached to the backside of the left ventricle and the heart was fully retracted with a suction tissue stabilizer. Five pigs underwent additional pump support. During retraction, the right ventricle was squeezed between the pericardium and interventricular septum, thereby decreasing its diastolic cross-sectional area by 62% +/- 6% (P <.001) while, concomitantly, right ventricular end-diastolic pressure increased to 165% +/- 19% (P =.004) of basal values. Stroke volume and mean arterial pressure decreased by 29% +/- 6% and 23% +/- 8% (P =.007 and P =.02, respectively). Left ventricular shape became somewhat elliptic without changes in preload pressure, and its diastolic cross-sectional area decreased by 20% +/- 3% (P =.001). All valves were competent. Right heart bypass restored left ventricular cross-sectional area, stroke volume, and mean arterial pressure. In contrast, left heart bypass increased blood pressure only marginally. Ninety-degree anterior displacement of the beating porcine heart caused primarily right ventricular dysfunction as a result of mechanical interference with diastolic expansion without concurring valvular incompetence. Right heart bypass normalized stroke volume and mean arterial pressure by increasing left ventricular preload; in contrast, left heart bypass failed to restore systemic circulation.Journal of Thoracic and Cardiovascular Surgery 09/1999; 118(2):316-23. · 3.53 Impact Factor
Hemodynamics in off-pump surgery: normal versus compromised
preoperative left ventricular function
Giuseppe Fiore*, Maria Elena Latrofa, Pasquale Tunzi, Maria Traversa, Corrado Fondacone,
Nicola Marraudino, Luigi de Luca Tupputi Schinosa, Tommaso Fiore
Department of Emergency and Transplantation, University of Bari, U.O. Anestesia e Rianimazione I, U.O. Cardiochirurgia, A.O. Policlinico,
Giuseppe Fiore, via A. De Ferraris 16, I-70124 Bari, Italy
Received 2 July 2004; received in revised form 9 November 2004; accepted 17 November 2004
Objective: Off-pump coronary surgery (OPCABG), avoiding cardiopulmonary bypass and cardioplegic arrest, seems to be a better choice in
patientswith poor baselinecardiacfunction.Since cardiocirculatory collapsecould be inducedby heart displacement in thisgroupof patients at
high risk, a greater pathophysiologic understanding of the hemodynamic derangements occurring in such patients is needed. Methods: Twenty-
eight elective OPCABG patients were evaluated for hemodynamic changes induced by heart displacement, using arterial thermodilution to
measure cardiac output and global end-diastolic volume. Hemodynamic parameters were recorded: at baseline; during proper exposure and
stabilization of each vessel; and at the end of surgery. Patients were divided into two groups, according to baseline ejection fraction (EF): group
A (EFO30%; NZ16), group B (EF%30%; NZ12). Results: Heart displacement induced a significant drop in the cardiac and stroke index, with a
lesser decrease of mean arterial pressure because of raised systemic vascular resistance. Preload, measured as global end diastolic volume,
significantly decreased in group A, while it remained unchanged or increased in group B. Linear regression between the preload index and left
ventricular stroke work was significant only in group A. Conclusions: Patients with poor baseline cardiac function can well tolerate OPCABG.
However, the pathophysiologic modifications underlying the hemodynamic changes are different compared to those in patients with good
preoperative cardiac performance.
q 2004 Published by Elsevier B.V.
Keywords: Beating heart; Coronary artery bypass surgery; Hemodynamics; Left ventricular function; Off-pump
Off-pump coronary artery bypass surgery (OPCABG) by
median sternotomy is becoming increasingly popular, as in
most patients it allows complete myocardial revasculariza-
tion with excellent short term results. The hemodynamic
modifications induced by heart displacement are usually
transient and reversible, and the technique seems to be safe
even in patients with poor left ventricular function,
improving myocardial preservation and leading to successful
results . However, some patients develop significant
intraoperative hemodynamic instability requiring intra-
aortic balloon counterpulsation (IABP) or cardiopulmonary
bypass (CPB) , and recently Mishra  identified very
low ejection fraction (!25%), recent myocardial infarction
(!1 month), congestive heart failure and preoperative
hemodynamic instability as risk factors for cardiocirculatory
collapse during OPCABG. Because of the potentially cata-
strophic effects of an emergent CBP in a patient in acutely
deteriorating conditions, an in-depth knowledge of the
hemodynamics occurring during cardiac displacement,
along with careful monitoring, is of paramount importance
for the safe management of patients at risk.
Assessment of cardiac preload permits a better patho-
physiologic evaluation of hemodynamic derangements.
Arterial thermodilution, besides measurement of cardiac
output (CO), allows calculation of the global end diastolic
volume (GEDV), proven to be a reliable preload measure-
ment . The aim of the present study is to evaluate the
hemodynamic changes induced by cardiac displacement for
multivessel off-pump coronary grafting in patients with both
normal and poor preoperative left ventricular function using
arterial thermodilution for CO and preload assessment.
2. Material and methods
Twenty-eight patients scheduled for elective multivessel
OPCABG were prospectively enrolled. Informed consent was
obtained from all patients, and the study was approved by
our ethics committee.
European Journal of Cardio-thoracic Surgery 27 (2005) 488–493
1010-7940/$ - see front matter q 2004 Published by Elsevier B.V.
* Corresponding author. Tel.: C39 080 5614 221.
E-mail address: email@example.com (G. Fiore).
Exclusion criteria were: evolving myocardial infarction,
preoperative hemodynamic instability and preoperative
IABP. Unlike other studies , high risk patients, defined
as patients with low ejection fraction (!30%) or recent
myocardial infarction (!1 month), were not excluded.
According to the preoperative left ventricular function,
patients have been divided in two groups:
– Group A: normal to moderately depressed left ventricular
function (preoperative EFO30%).
– Group B: poor left ventricular function (preoperative
All patients were hemodynamically stable in the morning
of surgery, with no need of IABP or other intravenous
pharmacologic support but nitroglycerin and heparin.
Patients received oral Diazepam 0.015 mg/kg 1 h before
surgery as premedication. Preoperative b-blockers, nitrates
and/or calcium-channel-blockers were continued until the
morning of surgery. General anesthesia was induced with
Thiopental (1–3 mg/kg), and maintained with Isoflurane
(0.5–1%) and incremental doses of Fentanil. Vecuronium
Bromide was used for neuromuscolar blockade. Patients
were mechanically ventilated with an oxygen/air mixture
(FiO2Z0.4), setting a respiratory rate of 10 per minute and a
minute volume adjusted to allow normocapnia.
The right radial artery was cannulated in all patients to
monitor arterial blood pressure. A triple-lumen central
venous catheter was inserted into the right internal jugular
vein. The femoral artery was cannulated with a 4F
thermistor-tipped catheter (Pulsion PV2014, Pulsion,
Germany) connected to the PiCCO device (Pulsion Medical
Systems, Munich, Germany) for transpulmonary thermodilu-
tion and continuous CO monitoring by pulse-contour tech-
nique. Leads II and V5 were continuously displayed to ensure
ischemia detection. Cautious volume expansion was used, as
required, to normalize volemia before cardiac displace-
ment. No patient was given intraoperative b-blockers or
calcium-channel-blocker infusion. It was planned to use
inotropic and/or vasoconstrictor agents to treat significant
hypotension (MAP!60 mmHg) or low cardiac output (CI!
2 l/min/m2) outlasting the time of cardiac displacement.
Exposure and stabilization of the target coronary vessels
were achieved by a modified Lima stitch  and a suction
type stabilizer (Octopus III Tissue Stabilizer, Medtronic, Inc.,
Minneapolis, MN). A gentle right decubitus Trendelenburg
position yielded better surgical conditions and improved
venous return . Right hemisternum elevation and exten-
sive right pleurotomy were performed to limit cardiac
compression . The strategy was to always graft first the
left anterior descendent coronary artery (LAD) with the left
internal mammarian artery (LIMA), to restore blood flow as
soon as possible to the anterior wall with minimal displace-
ment of the heart. The distal anastomoses on the diagonal
(DG), ramus intermedius (RI), obtusa marginalis (OM) and
posterior descendent (PDA) arteries were performed without
returning the heart to its resting position between the
successive anastomoses, firstly bypassing the more severe
stenosis to allow collateral flow.
The following hemodynamic parameters were analyzed:
mean arterial pressure (MAP), central venous pressure
(CVP), heart rate (HR), cardiac index (CI), stroke index
(SI), global end-diastolic volume index (GEDVI), systemic
vascular resistance index (SVRI), and left ventricular stroke
work index (LVSWI).
Measurements were performed according to the following
(a) Baseline, with the chest and pericardium open.
(b) Five minutes into the construction of each distal
(c) Final (with the heart back in its anatomical position).
Arterial thermodilution measurements were performed
injecting boluses of 15 ml cool 5% glucose in water in the
central venous catheter and recording the thermal dilution
curves by the termistor-tipped catheter inserted in the
femoral artery and connected to PiCCO.
CO was calculated from the thermodilution curve by the
Two other parameters were calculated from the analysis
of the thermal dilution curve:
– Mean Transit Time (MTt), which is the mean difference
between the time until the first indicator particle has
arrived at the point of detection and the time of arrival of
all the following particles
– Downslope Time (DSt), which is the time of the
exponential decay of the thermodilution curve.
The product of CO and MTt is the the so called ‘needle to
needle volume’, that is the volume between the point of
injection and the point of detection of the thermal
indicator. This volume represents the intrathoracic total
volume (ITTV) . The product of CO and DSt is the volume
of the largest mixing chamber between the site of injection
and the site of detection , that is, for temperature, the
pulmonary total volume (PTV). The difference between ITTV
and PTV is GEDV, the sum of blood volumes in both right and
left cardiac chambers at end diastole.
LVSWI has been calculated by the formula: LVSWI
2.1. Statistical analysis
All values have been indexed to body surface area. All
A 2 Levels Between Group by 7 Levels Within Subjects
Repeated Measures ANOVA with post-hoc Tukey’s testing for
multiple comparisons was used to analyse the hemodynamic
changes induced by heart displacement.
The relationship between GEDVI and LVSWI was analysed
by linear regression. A P value of !0.05 was considered
Preoperative and intraoperative characteristics of the
two groups of patients are summarized in Table 1.
G. Fiore et al. / European Journal of Cardio-thoracic Surgery 27 (2005) 488–493489
A total of 150 hemodynamic measurements were
The hemodynamic modifications induced by heart dis-
placement in each group of patients are shown in Table 2.
At baseline, patients in group B had a significantly lower
CI, SI, and LVSWI and higher SVRI and GEDVI compared to
patients in group A.
In both groups there was a significant drop of CI and SI
(Fig. 1) in all grafting set-up, with an increase in SVRI
(significant only in group A) (Fig. 2) and a decrease of MAP
(Fig. 3). CVP significantly increased in both groups. LVSWI
significantly decreased in each heart position in group A and
in group B. The main hemodynamic changes were recorded
during RI and OM grafting.
In both groups heart displacement induced similar
hemodynamic changes in all parameters except GEDVI
(Fig. 4). In patients with EF O30% (group A), GEDVI uniformly
decreased during cardiac manipulation, remaining lower at
the end of surgery compared to baseline. On the contrary, in
patients with an EF %30% GEDVI was unchanged during LAD
and DG anastomosis, increasing at the time of RI, OM and
PDA grafting. Final values of GEDVI in patients of group B
remained at a higher level compared to baseline, although
this was not statistically significant.
Patients in group B received an overall amount of fluids
significantly lower than patients in group A, and the two
groups were comparable for fluid balance at the end of
No patient developed significant hypotension (MAPO
60 mmHg) prompting administration of vasoconstrictor
agents, and CI reduction rapidly resolved with the heart
back in its anatomic position, never requiring inotropic
Both CI and MAP returned to baseline values at the end of
surgery, except even though a moderate increase of HR
caused a lower final SI especially in group A.
The linear regression between GEDVI and LVSWI (Fig. 5)
was significant only in group A patients, with no significant
correlation in patients of group B.
Both groups of patients in our study show a significant
drop of CI and SI during cardiac displacement, with a better
preserved MAP due an increase of SVRI. These changes
reversed promptly when the heart was back in its anatomic
position. At the end of surgery, CI and MAP returned to
baseline values, with a significantly increased HR which led
to a slight final reduction of SI.
Most studies, both experimental and clinical, report a
drop in CO and SV in response to heart displacement during
OPCABG, which is usually more evident while grafting the
posterior and inferior wall vessels. These hemodynamic
changes are related to many factors (heart displacement,
compression by the stabilizer, occlusion of the coronary
artery), vary according to the location of the vessel to be
Preoperative and intraoperative patients characteristics
Group A (nZ16)Group B (nZ12)
IMA !1 month
History of CHF
Number of grafts
39/56 (69.6%)30/38 (78.9%) n.s.
2253.6G718.9 ml 1084.1G415.3 mlP!0.05
EF, ejection fraction; IMA, myocardial infarction; CHF, congestive heart
Hemodynamic changes induced by heart displacement in the two groups
SVRI (dyn s m2/cm5)
LVSWI (g m/m2)
SVRI (dyn s m2/cm5)
LVSWI (g m/m2)
Values are meanGSD; BSL, baseline; LAD, left anterior descending artery; DG, diagonal artery; RI, ramus intermedius; OM, obtusa marginalis; PDA, posterior
descendent arteries; CI, cardiac index; SI, stroke index; HR, heart rate; MAP, mean arterial pressure; SVRI, systemic vascular resistance index; GEDVI, end-diastolic
global volume index; CVP, central venous pressure; LVSWI, left ventricular stroke work index. Statistical analysis (ANOVA): within groups:aP!0.05;bP!0.01;
cP!0.001 compared to baseline, Between groups:dP!0.05;eP!0.01;fP!0.001 group A compared to group B.
G. Fiore et al. / European Journal of Cardio-thoracic Surgery 27 (2005) 488–493490
grafted, and depend also on preoperative ventricular
function, heart size and coronary anatomy . However,
the precise mechanisms compromising cardiac function are
not fully understood.
In an experimental model on pig, using a suction-type
stabilizer (Octopus), Gruendemann found that lifting the
heart to expose the infero-lateral wall caused a decrease of
MAP and CO, with markedly increased right ventricular end-
diastolic pressure coupled to echocardiographic evidence of
marked compression of the right ventricle and an elliptically
shaped left ventricle. Interestingly, a 208 Trendelenburg
position normalized MAP, CO and SV at the expense of a
further rise in right and also left filling pressure, correspond-
ing to an increased biventricular preload shown by echo-
cardiography . These findings suggest that a severe
reduction in venous return to the folded and crumpled
right ventricle is the main mechanism of hemodynamic
impairment during inferolateral wall exposure. By increasing
venous return, Trendelenburg pushes open the right ven-
tricle, improving left ventricular filling. However, exper-
imental findings on healthy animals should be applied
cautiously in coronary artery disease patients, who often
suffer from poor left ventricular function. Actually, in a
clinical study on 44 OPCABG patients , which reported
hemodynamic and TEE modifications similar to those in
Gruendemann’s study, the Trendelenburg position did not
reliably normalize CO. In another clinical study on 17
OPCABG patients, using transesophageal echodoppler, Bis-
was  showed a significant decline of regional left
ventricular function during circumflex anastomosis com-
pared to LAD and right coronary artery grafting, with a
significant reduction of left ventricular compliance (a
restrictive diastolic filling pattern on transmitral and
pulmonary venous flow velocimetry).
A similar decrease of all measured indices of left
ventricular systolic function in response to heart displace-
ment was reported by Torracca , using an intraventri-
cular conductance catheter to evaluate hemodynamics in
eight OPCABG patients, two of whom had an EF!30%. In this
study exposure of the inferolateral vessels, especially after
stabilizer positioning, caused a drop in CI with an unchanged
left ventricular end-diastolic volume and a clear-cut,
although not statistically significant, left ventricular end-
systolic volume increase (from 48G22 to 61G26 ml/m2).
Such a disagreement between an unchanged preload and a
reduced SI further point out the role of reduced systolic
function in the hemodynamic compromise due to cardiac
All these findings suggest that probably hampered
diastolic filling is not the sole cause of hemodynamic
compromise during heart displacement and stabilization,
and various mechanisms, such as right ventricular failure
, left ventricular regional wall motion abnormalities
Fig. 1. Change of the stroke volume index during and after coronary artery
anastomosis in groups A and B. Abbreviation are the same as defined in
Table 2.* P!0.05 between group.
Fig. 4. Change of the end-diastolic global volume index during and after
coronary artery anastomosis in group A and group B. Abbreviation are the
same as defined in Table 2. *P!0.05 between group, **P!0.01 between
group, ***P!0.001 between group.
Fig. 3. Change of the mean arterial pressure during and after coronary artery
anastomosis in groups A and B. Abbreviation are the same as defined in
Fig. 2. Change of the systemic vascular resistance index during and after
coronary artery anastomosis in groups A and B. Abbreviation are the same as
defined in Table 2. *P!0.05 between group.
G. Fiore et al. / European Journal of Cardio-thoracic Surgery 27 (2005) 488–493491
, and mitral valve annulus distortion  all contribute,
leading to a more complex disturbance of global heart
function, especially in patients with a baseline poor cardiac
Because of the central role of preload in hemodynamic
modifications induced by heart displacement, methods
yielding an on line evaluation a ventricular filling are of
paramount importance to a correct pathophysiologic
assessment during OPCABG. Filling pressures are not useful,
because markedly influenced by changes in ventricular
distensibility, due to compression and possibly ischemia,
and by hydrostatic effect, due to cardiac verticalization.
The intrathoracic blood volume (ITBV), measured by
double-dilution technique, has been described as a new
approach to the estimation of cardiac preload . The
ITBV is a more reliable indicator of cardiac preload than
pulmonary occlusion pressure in critically ill  and CABG
patients , and it correlates to thermodilution CO and SVI
during acute experimental hemorrhage . Recently,
GEDV has been shown to be linearly related to ITBV,
allowing preload assessment by simple thermal dilution in a
peripheral artery .
In the present study, GEDVI, used as an index of preload,
underwent significantly different modifications in patients
with poor baseline left ventricular function (group B),
compared to patients with normal or moderately depressed
left ventricular function (group A). This finding gives possible
insights about different pathophysiologic mechanisms under-
lying hemodynamic modifications induced by heart displace-
ment. First of all, patients in group B show a significantly
higher GEDVI compared to group A, as a reflection of their
lower EF. A far more important finding is the behaviour of
preload, measured as GEDVI, inside each group, in response
to cardiac displacement. Actually, facing a similar CI and SI
reduction, GEDVI is significantly reduced in group A but
remains unchanged or significantly increases (at the time of
inferolateral and inferior wall exposure) in group B, in
agreement to what reported by Torracca . Such a
different behaviour is not the expression of the lower EF in
patients of group B. In fact, patients with different EF should
respond in a fairly similar way to similar preload changes,
whereas our two groups of patients respond in a similar way
(reduction of SV) to opposite changes of preload. These
findings suggest a different mechanism underlying CI
reduction induced by heart displacement in the two groups.
In other words, cardiac displacement behaves as a challenge
to ventricular pumps, and different hearts adapt to this
challenge in a different way, according to their baseline
function. In our study, patients of group A, with a fairly good
myocardial performance, suffer only the effects of the
reduced venous return to the restricted ventricles, and show
a reduced SV as a consequence of the decreased preload. On
the other hand, in patients of group B, in whom a recent
acute myocardial infarction was complicated by a severely
compromised ventricular performance, the restrictive
effect on venous return is in some way overwhelmed by
the ventricular dilatation due to a further decrease of an
already low EF. That is to say, cardiac displacement acts not
only hindering venous return by an increase of biventricular
rigidity; in some cases its effect might be a (further) reduced
systolic performance and/or hampered ventricular ejection
resulting in a decreased SV along with a dilated ventricle.
To better assess cardiac performance in our two groups of
patients, we evaluated the relationship between preload,
measured as GEDVI, and LVSWI. This relationship, called
preload recruitable stroke work (PRSW), has been shown to
be linear and independent of loading, geometry and heart
rate ; its slope has been proposed as a potential measure
of myocardial performance . In our study, linear
regression between GEDVI and LVSWI was significant only
in group A patients, whereas the regression points were
widely scattered of in our group B patients (Fig. 5). This
finding confirms that in patients of group A heart displace-
ment causes mainly a preload reduction with an unchanged
myocardial performance, mimicking the effects of vena
caval occlusion used in experimental models. The lack of
correlation between the index of preload and LVSWI in group
B is more difficult to explain. The most obvious explanation
is a depressed left ventricular contractility during cardiac
manipulations, changing the slope of PRSW relationship, so
that individual points cannot be aligned on the same curve.
Actually, a non linear PRSW relationship has been hypoth-
esized  in ventricles with a baseline depressed function
due to a greater afterload sensitivity, and Ryan  reported
simultaneous changes both in slope and in x-axis intercept of
PRSW line in ischemic ventricles, due to the so called ‘creep
phenomenon’, making the evaluation of such ventricles
difficult by this model. Moreover, a decreasing LVSWI
together with a rising preload could also be the expression
of deficient length-dependent activation related to
exhaustion of the physiologic preload recruitment mechan-
ism in disfunctional ischemic left ventricles, as reported by
De Hert .
All these findings seemingly point to a different patho-
physiologic mechanism of the hemodynamic changes
induced by heart displacement in the two groups of patients.
Our findings should prompt different considerations when
treating low CO during OPCABG. In fact, if postural
manoevers and volume expansion seems to be all what is
needed in patients with a good baseline cardiac performance
(REF), this could be less than optimal, or even deleterious, in
subgroups of patients whose baseline myocardial perform-
ance is severely compromised by a recent acute myocardial
infarction. These patients require more strict hemodynamic
monitoring by techniques allowing ventricular volume
Fig. 5. Linear regression between global end diastolic volume (GEDVI) and left
ventricular stroke work index (LVSWI).
G. Fiore et al. / European Journal of Cardio-thoracic Surgery 27 (2005) 488–493492