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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 5, September/October 2016
288
AFRICA
detailed review by the paediatric cardiologist (AD) to classify
CHD according to standard nomenclature used by the Society of
Thoracic Surgery congenital heart surgery database (Table 1).
12
Statistical analysis
Data are reported as mean
±
SD or median with intervals. We
used the
t
-test for paired data. The SPSS 20 (IBM SPSS Statistics
version 20 x86 Multiple languages) and Origin statistical
packages were used.
Results
We recorded 2 156 patients with CHD and of these, 128 (6%)
had DS. The median age of patients at diagnosis was 9.5 months
(2 days to 16 years), with 40.4% of patients diagnosed before six
months of age. The male-to-female ratio was 1:1. The median
age of mothers at delivery was 39 years (16–47) (Fig. 1) and the
consanguinity rate was 22%. The distribution of different types
of CHD is shown in Table 1. Overall, 186 CHDs were diagnosed
in our study population; 75 patients (58.6%) had a single cardiac
lesion versus 56 (41.4%) with multiple cardiac lesions.
When considering individual CHDs, atrioventricular
septal defect (AVSD, 29.9%) was the most common cardiac
abnormality. Among these AVSDs, the complete form was the
most frequent type, found in cases 46 cases (85.2%) and, of those
complete forms of AVSD, Rastelli class C AVSD was found to be
the most frequent and was reported in 34 cases (74%).
Ventricular septal defect (VSD) was the second most common
cardiac abnormality (21.5%). Perimembranous VSDs were
reported in 28 cases (70%) and other VSD forms were reported
in 16 cases (30%).
Atrial septal defect (ASD, 19.9%) was the third most common
single lesion. Most of these ASDs were of ostium secundum
form (95%), while the other forms (sinus venosus) were noted
in 5%. Patent ductus arteriosus (PDA) was diagnosed in 16.57%
and tetralogy of Fallot (TOF) in 5%.
The most frequent associations of CHD were AVSD
+
ASD
(9.3%), VSD
+
ASD (6.2%) and VSD
+
PDA (5.5%). Pulmonary
arterial hypertension (PAH) was seen in 68 patients (53%) and
Eisenmeiger syndrome in four patients (3.1%).
Surgery was indicated in 54% (69 patients) but for many
reasons (no agreement from the parents, lack of financial
resources, etc), a surgical procedure was done in only 42 patients.
In those surgically treated patients, 87% presented with ASD,
and 68, 64 and 60% with VSD, PDA and AVSD, respectively
(Fig. 2). In addition, 23 and 15% of patients remained either
under medical treatment or observation, respectively.
The mortality rate observed in our population was 14.1%,
and another 29.7% were lost to follow up (Table 2). For those
Table 1.Types of congenital heart defects
in patients with Down syndrome
Type of CHD
CHD feature,
n
(%)
(
n
=
186)
Atrioventricular septal defect (AVSD)
54 (29)
Complete AVSD
46/54 (85)
• Rastelli type A
12/54 (26)
• Rastelli type B
0
• Rastelli type C
34/54 (74)
• Balanced
45/54 (98)
• Unbalanced
1/54 (2)
Partial AVSD
1 (1.9)
Intermediate AVSD
7 (12.9)
Ventricular septal defect (VSD)
40 (21.5)
Perimembranous
28/40 (70)
Subpulmonary
4/40 (10)
Muscular
4/40 (10)
Inlet
4/40 (10)
Atrial septal defect (ASD)
37 (19.9)
Ostium secundum
35/37 (95)
Sinus venosus
2/37 (5)
Patent ductus arteriosus (PDA)
31 (16.7)
Tetralogy of Fallot (FT)
10 (5.4)
Valvular disease
6 (3.2)
Mitral valvular insufficiency
5/6 (83)
Aorticvalvular insufficiency
1/6 (17)
Other
8 (4.3)
Left superior vena cava
3/8 (37)
Pulmonary stenosis
2/8 (25)
Coartaction of the aorta
1/8 (12)
PAPVC
1/8 (12)
Double outlet right ventricle
1/8 (12)
PAPVC: partial anomalous pulmonary venous connection.
<
20 20–25 25–30 30–35 35–40 40–45
>
45
30
25
20
15
10
5
0
3
5
6
10
17
26
6
Fig. 1.
Mothers’ ages of patients with Down syndrome at
delivery.
All patients AVSD VSD ASD PDA
%
100
80
60
40
20
0
surgery group
lost to follow-up subgroup
non-surgery group
61%
60%
21% 19%
22% 19% 18% 14%
68%
87%
64%
14%
7% 7%
21%
Fig. 2.
Rates of surgical procedures for the whole group of
patients with Down syndrome and congenital heart
disease and for the most frequent congenital heart
defects in these patients. AVSD: atrioventricular septal
defect; VSD: ventricular septal defect. ASD: atrial
septal defect; PDA: patent ductus arteriosus.