CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 1, January/February 2013
AFRICA
37
Methods:
A prospective observational study was carried out from
2001 until June 2012; 203 patients underwent re-routing of pulmo-
nary veins for TAPVC during this period. The median age was 89
days (1 day – 34 years); 127/203 had varying degrees of obstruction
at different levels (supracardiac: 76, cardiac: 25, infradiaphragmatic:
17, mixed: nine). Five of 203 were re-do surgeries for obstruction
at the anastamotic site; 42/127 obstructed TAPVC presented with
circulatory collapse needing pre-operative resuscitation. No patient
was refused surgery. Management strategies included (1) urgent
surgery irrespective of haemodynamic status, (2) quick and accurate
surgery, (3) deferred sternal closure, (4) epicardial echo in all to
confirm accuracy of repair. Peri-operative pulmonary hypertension
and associated low cardiac output was managed pre-emptively using
multiple simple, inexpensive conventional strategies (intra-operative
ultrafiltration, fluid restriction, peritoneal dialysis, lung recruitment,
milrinone, calcium infusion, corticosteroids in refractory cases and
elective non-invasive ventilation after extubation) with limited use
of catecholamines.
Results
: In-hospital mortality was four out of 203 (1.97%). There
were two late deaths after hospital discharge due to non-cardiac
causes. Median ventilatory requirement was 52 hours and median
length of stay 11.2 days.
Conclusion
: Successful re-routing of TAPVC in sick infants with
pulmonary hypertension and severe right ventricular dysfunction
is feasible without ECLS or inhaled nitric oxide, with minimum
morbidity.
953: COMPARISON OF THREE INOTROPIC STRATEGIES
IN THE NEWBORN AFTER STUNNING OF THE RIGHT
VENTRICLE
Janus Hyldebrandt, Johan Heiberg, Christian Frederiksen, Michael
Schmidt, Hanne Ravn
Aarhus University Hospital, Skejby, Denmark
The immature myocardium has significantly different beta-receptor
kinetics, metabolism and enzyme activity from the adult. We there-
fore undertook a piglet study to investigate the efffect of three differ-
ent inotropic strategies.
Methods:
Twenty-eight piglets aged four days were prepared, to
measure cardiac output (CO), and central venous and arterial pres-
sures. Stunning of the right ventricle (RV) was induced by 10 cycles
with ischaemia–reperfusion injury. Animals were randomised to one
of three inotropic protocols or placebo: (1) AM: adrenaline: 0.09
μ
g.kg
-1
min
-1
and milrinone: 50
μ
g.kg
-1
bolus and 0.4
μ
g.kg
-1
min
-1
,
(2) DM: dopamine: 6
μ
g.kg
-1
min
-1
, milrinone: 50
μ
g.kg
-1
bolus and
0.4
μ
g.kg
-1
min
-1
), (3) Dob: dobutamine (8
μ
g.kg
-1
min
-1
), (4) saline (2
ml.kg
-1
h
-1
). One-way ANOVA with Tukey’s multiple comparison test
was used to test differences between groups.
Results
: Cardiac output (CO) had decreased by 29% in the placebo
group 60 min after RV stunning. CO was significantly higher
in the AM- and DM-treated animals, compared to placebo (
p
<
0.05), whereas Dob-treated animals remained unchanged. CO in
DM-treated animals was significantly higher compared to that in
Dob-treated animals. MAP was maintained in the DM animals, but
decreased by more than 35% in AM- and Dob-treated and placebo
animals after RV stunning. MAP decreased after 180 min in AM-
(–37%) and Dob- (–44%) treated groups, and to the same extent in
the control group (–41%) (ns). In the DM group, MAP remained
stable throughout the observation period (–5%), in contrast with the
other intervention groups (
p
<
0.001). SVRI decreased 14% (
p
=
0.1)
during I/R. During the observation period SVRI decreased further by
approximately 46% (
p
=
0.01) with no difference between control and
any intervention group.
Conclusions
: Following I/R injury of the right ventricle, optimal
haemodynamics in newborn piglets was significantly better main-
tained in the DM-treated animals compared to AM and Dob treat-
ment.
956: MECHANISMS OF EXERCISE INTOLERANCE IN
ADOLESCENTS WITH REPAIRED PULMONARY ATRESIA
WITH INTACT VENTRICULAR SEPTUM: A CONGENITAL
HEART SURGEONS’ SOCIETY STUDY
BrianMcCrindle
1
, Jeffrey Poynter
1
, HenryWalters
2
, Igor Bondarenko
2
,
Linda Lambert
2
, Stephanie Fuller
2
, Tara Karamlou
2
, Marco Ricci
3
,
Jeff Jacobs
4
, Jonathan Rhodes
5
1
Hospital for Sick Children,
2
Division of Cardiovascular Surgery, Children’s Hospital of Michigan,
USA
3
University of New Mexico Health Science Center, New Mexico,
USA
4
Children’s Hospital of Michigan, USA
5
Boston Children’s Hospital, USA
Background
: Among patients with pulmonary atresia with intact
ventricular septum (PAIVS) for whom the optimal repair type is
unclear, there are some for whom selection of biventricular repair
diminishes survival rate and may impair late functional outcomes.
We sought to determine the late patterns of exercise intolerance and
associated factors.
Methods
: From 1987 to 1997, 448 neonates with PAIVS were
enrolled on presentation; 79/271 survivors underwent exercise test-
ing in a cross-sectional follow-up study. An expert reviewed blinded
exercise test results and grouped patients by the mechanism of
exercise intolerance. Groupings were then related to demographics,
neonatal morphology and repair type.
Results
: Study participants (median age 17.2 years) included
44 biventricular, 22 univentricular and 13 1.5-ventricle repairs.
Mechanisms of exercise intolerance were: 18 (23%) reduced stroke
volume, three (4%) chronotropic insufficiency and three (4%)
desaturation, with one patient having all three mechanisms; 32 (41%)
were unclassifiable due to submaximal effort or missing data, and
25 (32%) were normal. Exercise intolerance by any mechanism was
associated with lower body mass index (BMI)
z
-score at testing (OR
=
2.17,
p
<
0.05) and smaller birth weight (OR
=
1.02,
p
<
0.05).
Exercise intolerance showed a trend of association with larger initial
right ventricular size (OR
=
1.64,
p
=
0.08) and higher pre-operative
left ventricular systolic pressure (OR
=
1.07,
p
=
0.09). Lower BMI
z
-score at exercise testing (OR
=
1.79,
p
<
0.05) and absence of coro-
nary–cameral fistulae (OR
=
13.28,
p
<
0.05) were associated with
exercise intolerance due to reduced stroke volume. Repair type and
initial tricuspid valve
z
-score had no association or interaction with
exercise intolerance.
Conclusions
: Late exercise intolerance after repair of PAIVS is
common. Although not directly associated with repair type, exercise
intolerance is associated with morphological surrogates for biven-
tricular repair. Failure to augment stroke volume during exercise
appears to equally affect patients with Fontan physiology and patient
status post biventricular repair, perhaps due to ongoing right heart
hypoplasia, non-compliance or impaired ventricular interaction.
962: RECONSTRUCTION OF THE RIGHT VENTRICULAR
OUTFLOW TRACT WITH A TRANSANNULAR PATCH AND
MONOCUSP POLYTETRAFLOURETHYLENE VALVE
Torsten Malm, Petru Liuba, Nina Hakacova, Franziska Tilesch, Adam
Åkerman, Jens Johansson Ramgren, Sune Johansson
University Hospital, Lund, Sweden
Background:
Corrective surgery of a hypoplastic RVOT often
requires transannular patching, followed by pulmonary incompe-
tence, right ventricular dysfunction, arrhythmias, etc. Different
techniques have often been tried to restore valve function, with
disappointing results. More recently, use of a PTFE monocusp valve
has been suggested as a better alternative with limited data so far on
long-term results.
Methods:
Between 2003 and 2011 a total of 58 patients (54 Fallot,
two AVSD with Fallot, one PA,VSD and one PS) underwent RVOT
reconstruction with PTFE monocusp and transannular patch; 25 had
