CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 1, January/February 2013
AFRICA
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in-depth analysis using sophisticated statistical methods, modelling
and GIS mapping is in progress.
1691: COMPARISON OF SHEAR STRESS RATE DISTRIBU-
TION AFTER NORWOOD WITH RIGHT VENTRICLE-TO-
PULMONARYARTERYCONDUITANDBLALOCK-TAUSSIG
SHUNT FOR HYPOPLASTIC LEFT HEART SYNDROME:
MATHEMATIC MODELLING OF HAEMODYNAMICS
Tomasz Mroczek, Zbigniew Malota, Janusz Skalski
Department of Pediatric Cardiac Surgery, Jagiellonian University,
Krakow, Poland
Objective:
The introduction of right ventricle to pulmonary artery
(RV-PA) conduit instead of Blalock-Taussig shunt (BTS) for
Norwood procedure for hypoplastic left heart syndrome resulted
in a higher survival rate in many centres. Exact mechanisms and
long-term results are still under investigation. The main objective of
this study was the comparison of shear stress rate (SSR) distribution
in two models of Norwood physiology regarding different types of
pulmonary blood flow sources.
Method:
Based on anatomical details obtained from echocardio-
graphic assessment and angiographic studies, two three-dimensional
computer models of post-Norwood physiology with RV-PA 5 mm
conduit and Blalock-Taussig shunt (BTS) 3.5 mm shunt were devel-
oped. The finite-element method was applied for computational
simulations. Shear stress distribution was analyded in both models at
basal level of pulmonary and systemic vascular resistances and also
with decreased systemic vascular resistance and increased pulmonary
vascular resistance.
Results:
The highest values of SSR were observed in shunts both in
RVPA and BTS Norwood models during the peak systolic phase. The
imperfect reconstruction of the aorta influences the local distribution
of SSR. Changes of systemic and pulmonary vascular resistance do
not change significantly the distribution patterns of SSR in both
models.
Conclusions:
The sources of pulmonary blood flow are the areas of
the highest SSR. The way of reconstruction of the aorta influences
the local distribution of SSR.
1716: COMPLEX APPROACH TO HIGHLY MALIGNANT
LONG QT SYNDROME IN A 2-YEAR-OLD GIRL
Viera Illikova
1
, DusanPoruban
2
, Vladimir Cingel
3
, Robert Hatala
1
1
Departments of Arrhythmias and Pacing and ICU, Children’s Cardiac
Center and National Cardiovascular Institute, Bratislava, Slovakia
2
Department of Oro-Maxillofacial Surgery, St Elisabeth Institute of
Oncology, Bratislava, Slovakia
3
Department of Surgery, Children Faculty Hospital, Bratislava,
Slovakia
Background and objectives:
Clinical presentation and therapy
of long QT syndrome (LQTS) depends on the genetic type of the
syndrome. We present a case of a girl with clinical manifestation
suggesting LQTS type 1 or 2, resistant to betablocker therapy.
Methods:
A 2-year-old girl was admitted after syncope. Prolonged
QT interval and episode of torsade de pointes (TdP) was found.
Results:
Beta-blocker therapy was started with metoprolol. One
month later syncope recurred and frequent TdP occurred of a few
beats to 20 seconds’ duration. Propranolol was initiated and increased
to supramaximal dose with no effect on TdP frequency and minimal
effect on heart rate. Frequency of TdP increased to a few hundred
per day with increased duration and frequent loss of consciousness.
TdP were related to sympathetic discharge, completely disappear-
ing during sleep. Lidocaine and magnesium demonstrated no effect,
analgosedation had a partial effect. An implantable cardioverter-
defibrillator (ICD) was implanted and left cervical sympathetic
denervation (LCSD) performed. Mexiletine obtained with the help
of an international pharmacy resulted in complete elimination of
TdP episodes. One year later, the patient was successfully defibril-
lated from life-threatening TdP recurrence. Genetic testing revealed
SCN5A mutation P1332L.
Conclusion:
Beta-blocker therapy of LQTS in a girl with clini-
cal presentation suggesting LQTS type 1 or 2 was not successful.
A complex approach including ICD implantation and LCSD was
needed, with ICD serving as an emergency back-up treatment.
Surprisingly, lidocaine was without effect but mexiletine led to
disease control. Availability of mexiletine and genetic testing would
allow earlier appropriate treatment.
1718: CARDIAC INVOLVEMENT IN PATIENTSWITH BECK-
ER MUSCULAR DYSTROPHY
Joana Freitas
1
, Silvia Alvares
2
, Marilia Loureiro
2
, Manuela Santos
3
1
Pediatric Department, Centro Hospitalar do Porto, Porto, Portugal
2
Pediatric Cardiology Department, Centro Hospitalar do Porto, Porto,
Portugal
3
Pediatric Neurology Department, Centro Hospitalar do Porto, Porto,
Portugal
Background:
Cardiac involvement (CI) is an invariable feature
of Becker muscular dystrophy (BMD), and can be even more
pronounced than the skeletal muscle weakness. It may be subclini-
cal and detectable only by instrumental investigation, or sympto-
matic. Asymptomatic CI occurs in most cases, but up to one-third of
patients develop dilated cardiomyopathy (DCM) with concomitant
heart failure. The degree of symptomatic CI in BMD varies greatly.
The aim of this study was to assess the cardiac findings in patients
with BMD from the outpatient clinic of our institution.
Material and methods:
We did a retrospective review of clinical,
electrocardiographic and echocardiographic assessments of patients
with BMD.
Results:
The study included 11 patients aged 1–16 years at referral
to our paediatric cardiology centre. Long-term follow-up was 6.8
±
4.4 years. Patients were assessed annually from time of diagnosis or
more frequently according to the clinical manifestations. Only one
adolescent had complaints of poor exercise tolerance. Prevalence
of preclinical and clinically evident cardiac involvement was 55%.
Electrocardiogram was abnormal in 9% of patients. Echocardiogram
was abnormal in 55% of patients. Mild left ventricle enlargement was
present in 6 patients. Three patients were started on ACE inhibitors.
Conclusion:
Although most patients were asymptomatic, a high
percentage had evidence of cardiac involvement. Clinicians need to
be aware of the importance of myocardial involvement in patients
with BMD and the therapies available. Until aetiology-specific
genetic or cell-based therapies are developed, work in this area
should concentrate on (1) implementing the complementary consen-
sus recommendations for clinical care and research developed by
neuromuscular and cardiovascular specialists and (2) identifying
children with cardiomyopathy so currently available treatments can
be used appropriately.
1719: TREATMENT OF PATENT DUCTUS ARTERIOSUS IN
PRETERM NEONATES: SURGERY OR INDOMETHACIN?
Carolina Capuruco, Cleonice Mota
Federal University of Minas Gerais (UFMG), Brazil
Objectives:
The haemodynamically relevant patent ductus arteriosus
(PDA)
impairs pulmonary and cardiac function. This prospective
study evaluated the treatment and outcome in preterm newborns.
Methods:
Between January 2002 and January 2008, 3 043 newborns
were enrolled, of whom 231 (7.6%) presented with PDA and were
subdivided into groups depending on the treatment. Spontaneous
closure occurred in 39/231 (16.9%) and 17 (7.4%) died without
treatment. Indomethacin therapy was successful in 100 (43.3%)
patients, surgical closure was the first treatment in 55 (23.8%) and
20 (8.6%) undergoing ductal ligation after indomethacin failure. The
proportion of neonatal morbidities (chronic lung disease (CLD),
necrotising enterocolitis (NEC), haemorrhage intraventricular (HIV),
