CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 1, January/February 2013
AFRICA
209
1058:ASSESSMENT OF PULMONARYVASCULARVOLUME
AND LUNG PERFUSION IN PATIENTS WITH HYPOPLAS-
TIC LEFT HEART SYNDROME IN FONTAN CIRCULATION
USING CARDIOVASCULAR MAGNETIC RESONANCE
IMAGING
Eileen Pardun
1
, Michael Jerosch-Herold
2
, Christopher Hart
1
, Inga
Voges
1
, Dominik Gabbert
1
, Hans-Heiner Kramer
1
, Carsten Rickers
1
1
Department of Congential Heart Disease and Paediatric Cardiology,
Kiel, Germany
2
Brigham and Women’s Hospital, Boston, USA
Introduction
: Angiographic data indicate that children with hypo-
plastic left heart syndrome (HLHS) in Fontan circulation have a
smaller anatomical size of the central pulmonary arteries. We utilised
novel MRI techniques to assess pulmonary vascular volume and lung
perfusion to investigate whether HLHS patients had lower values
than lung healthy controls.
Methods:
Thirty-one children with HLHS (4.9
±
2.3 years) and eight
lung healthy controls (9.8
±
6.4 years) were studied. A modified
contrast-enhanced dynamic MR angiography sequence was used to
assess pulmonary vascular and total volume of the right and left side
of the lung. With the use of dedicated software we measured the lung
volume, relative pulmonary vascular volume, the rate of parenchy-
mal contrast enchancement (‘up-slope’), as well as the parenchymal
mean transit time (MTT) in order to assess pulmonary vascular status
and perfusion. Standardised cardiopulmonary exercise testing on a
treadmill was performed in all patients and compared to a cohort of
paediatric volunteers.
Results:
The indexed pulmonary total lung volume and the relative
vascular volume in HLHS were significantly reduced compared to
the control group (634
±
105 vs 945
±
274 ml/m²,
p
<
0.05; 6.5
±
3.7
vs 9.5
±
2.4%/m²,
p
<
0.05). Lung perfusion in children with HLHS
was also impaired compared to healthy children (MTT: 10.8
±
2 vs
6.7
±
3 s,
p
<
0.01; up-slope: 0.32
±
0.24 vs 1.12
±
0.305 s
-1
m
-2
;
p
<
0.01 s
-1
m
-2
;
p
<
0.01). Relative vascular volume showed no differ-
ence between the right and left lung and correlated significantly with
oxygen uptake measured by standard spirometry (Spearman’s
r
=
0.78;
p
<
0.01).
Conclusions:
Advanced MRI methods enabled the assessment
of pulmonary perfusion in HLHS patients in Fontan circulation.
HLHS patients had a reduced total lung volume, pulmonary vascular
volume, and an impaired lung perfusion, compared to controls. The
reduced vascular volume in HLHS patients appears to be an impor-
tant limiting factor for pulmonary function. Long-term follow-up
investigations are important to detect a potential further decline of
values during growth and which implication may occur for the func-
tion of the Fontan circulation.
1062: CONGENITAL LONG-QT SYNDROME: A SINGLE-
CENTRE EXPERIENCE
Sevcan Erdem, Alev Kiziltas, Osman Kucukosmanoglu, Nazan
Ozbarlas
Department of Paediatric Cardiology, Faculty of Medicine, Cukurova
University, Turkey
Background:
Congenital long-QT syndrome (LQTS) is character-
ised by prolonged ventricular repolarisation (QT interval prolonga-
tion) and a propensity for syncope and sudden death secondary to
torsades de pointes.
Methods:
In this report we identified 16 congenital LQTS patients
who were followed at Department of Paediatric Cardiology, Cukurova
University between 2000 and 2012. The mean age of the patients was
104 months, the mean follow-up period was 24 months, and mean
corrected QT interval was 0.52 ms.
Results:
At pre-diagnosis, nine patients (56%) had a history of synco-
pe, convulsions or cardiac arrest, and three patients were treated with
anti-epileptic drugs as they were misdiagnosed as epileptics. During
the follow-up period, two patients received implantable cardioverter
defibrillators (ICD). One was a boy with symptomatic bradicardia
on Holter ECG record and history of cardiac arrest of a first-degree
family member, and the other was a girl with recurrent sustained
ventricular tachycardia with syncope even though she was on medi-
cal therapy. All patients were treated with beta-adrenergic blockade
as soon as LQTS was diagnosed, and potentiated through maximal
heart rate on a treadmill exercise test. During the follow-up period,
no patient had cardiac arrest. We diagnosed LQTS in two patients’
asymptomatic first-degree relatives, just with ECG screening.
Conclusion:
Being a survivor of sudden cardiac arrest, having a
history of recurrent syncope, or history of sudden cardiac arrest in a
family member, and with a diagnosis of LQTS in relatives, genetic
determination must take into consideration during clinical follow up
of a congenitally LQTS patient. Beta-adrenergic blockade, avoidance
of triggering factors, ICD or permanent pacemaker implantation for
high-risk patients, and sympathetic ganglion blockade are treatment
choices for LQTS patients. Physicians must screen family members
with an ECG, and must overemphasise the history of recurrent
syncope attacks, convulsions or sudden cardiac arrest in patients with
suspicion of a LQTS diagnosis.
1063: VALUE OF RADIOFREQUENCY ABLATION VERSUS
CRYO-ABLATION FOR ATRIO-VENTRICULAR NODAL
RE-ENTRY TACHYCARDIA IN CHILDREN
Matthew Oster
1,2,3
, Zhou Yang
2
, Kay Steward-Huey
1
, Michelle
Glanville
1
, Arlene Porter
1
, Robert Campbell
1,3
, Brad Webb
1
, Margaret
Strieper
1,3
1
Children’s Healthcare of Atlanta, USA
2
Emory University Rollins School of Public Health, USA
3
Emory University School of Medicine, USA
Background:
Radiofrequency ablation (RFA) and cryo-ablation are
two strategies for treating atrio-ventricular nodal re-entry tachycardia
(AVNRT) in children, but it is unclear which strategy may offer better
value.
Methods:
We performed a retrospective cohort study of all AVNRT
ablation cases for children (age
≤
18 years) from 1 July 2009 to
30 June 2011 at a single institution. Cost data included fixed cost,
miscellaneous hospital costs, and labour costs. Outcomes data
regarding the acute long-term success (six months) of the ablations
were collected through chart review.
T
-test and regression analysis
were conducted to investigate any association between ablation
procedure type (RFA, cryo-ablation, or combination of both), and the
cost and long-term success rate of the ablation procedures, adjusting
for patient (age, BSA) and provider (experience) characteristics.
Results:
Of 96 unique cases, 48 were cryo-ablation only, 42 RFA
only, and six were a combination (four starting with RFA, two starting
with cryo-ablation). Acute success was 100% for the cryo-ablation
only and RFA only cases and 83% for the combination cases. There
were no notable adverse events. The average total cost was US$9 636
for cryoablation cases, US$9 708 for RFA cases, and US$10 967 for
combination cases. The difference in the cost between cryo-ablation
only cases and RFA only cases was not statistically significant. The
unadjusted long-term success rate was 79.1% for cryo-ablation only
cases, 92.8% for RFA only cases, and 66.7% for combination cases
(
p
<
0.05 for cryo-ablation only vs RFA only). After adjusting for
patient and provider characteristics, the difference between cryo-
ablation only and RFA only was not considered significant.
Conclusions:
There was no difference in costs or short-term success
rate for cryo-ablation vs RFA for treatment of AVNRT in children.
Differences in long-term success rates may be attributed to multiple
factors other than the choice of procedure and may lead to differences
in long-term costs if children are referred for repeat ablation.
1064: IMPACT OF BT SHUNT SIZE ON TRICUSPID REGUR-
GITATION IN HYPOPLASTIC LEFT HEART SYNDROME
Hiroko Asakai, Bryn Jones, Igor Konstantinov, Yves D’Udekem,
Christian Brizard, Michael Cheung
1
Royal Children’s Hospital, Melbourne, Australia
