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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 27, No 5, September/October 2016
312
AFRICA
(ES)] end-systolic longitudinal strain [SLSC (ES)] and positive
peak transverse strain (STSR peak P).
Segmental analysis showed that end-systolic longitudinal
strain [STSR (ES)] measurements of the basal posterior and
mid-posterior segments were statistically significantly lower
in the patient group (
p
<
0.05). End-systolic longitudinal
displacement [DLDC (ES)] of the basal posterior, mid-posterior
and mid-anterior septal segments were statistically significantly
lower in the patient group (
p
<
0.05).
Discussion
Wilson’s disease is an autosomal recessive inherited disease,
characterised by excessive copper storage in the body, especially
the liver and brain, and also in the heart tissue due to reduced
biliary copper excretion secondary to loss of the mutation
for copper-transporting ATPase (ATP7B). Wilson’s disease,
characterised by excessive copper deposition in the body,
primarily in the liver and brain, results from an inability of the
liver to excrete copper in the bile.
1,2
Cardiac involvement of Wilson’s disease has not been
sufficiently investigated. Electrocardiographic abnormalities,
cardiac arrhythmias, cardiomyopathy, autonomic dysfunction
and sudden cardiac death are rare complications but may be seen
in children with Wilson’s disease due to copper accumulation in
the heart tissue.
3-5
Arat
et al
. showed increased P-wave dispersion in adults
with cardiologically asymptomatic Wilson’s disease.
6
In another
study on adults, electrocardiographic abnormalities, including
left ventricular hypertrophy, early repolarisation, biventricular
hypertrophy, premature atrial or ventricular contractions, atrial
fibrillation, sino-atrial block and Mobitz type 1 atrioventricular
block were detected in 34% of the patients.
6
Electrocardiographic
abnormalities are not uncommon in Wilson’s disease and are
presumably related to an underlying cardiomyopathy due to
deposition of copper in the heart.
5
We previously evaluated 22 children with Wilson’s disease
with 24-hour ECG monitoring and our study showed that
one patient had first-degree atrioventricular block, one had
frequent sinus exit block, and four had rare ventricular ectopic
beat.
8
In our study, all the patients were assessed with ECG
before echocardiographic evaluation. Only one patient had
Wolf–Parkinson–White pattern, but there were no arrhythmias
or ECG abnormalities in any of the patients. We assumed that
ECG abnormalities develop over a long period or in untreated
patients.
The major pathological findings of the myocardium in
Wilson’s disease included the presence of interstitial and
myocardial fibrosis, focal myocarditis and cardiac hypertrophy,
conduction tissue degeneration, and early atherosclerosis due
to the toxic effect of copper, leading to mitochondrial injury
and lipid peroxidation, which is caused by reactive free oxygen
radicals. Hlubocka
et al
. suggested that cardiac changes seen in
Wilson’s disease are not only related to copper accumulation
but also to free oxygen radicals.
9
Therefore echocardiography is
an important tool to assess asymptomatic Wilson’s patients. In
this study, left ventricular wall thickness was increased and left
ventricular end-diastolic diameter was decreased in patients with
Wilson’s disease and the differences were statistically comparable
to the results of the control group. Measurement of local and
global myocardial function using non-invasive methods is a
major aim in clinical cardiology.
10
Cardiac systolic function may
deteriorate in prolonged disease or in untreated patients.
Table 7. Longitudinal and transverse strain and strain rate values
according to segment from the two-chamber view
Strain according to
segment
Patients (
n
=
21)
(mean
±
SD)
Controls (
n
=
20)
(mean
±
SD)
p
-value
SLSC peak G (%)
Basal inferior
–21.80
±
4.37
–21.14
±
6.86
0.70
Mid-inferior
–21.24
±
3.56
–20.69
±
6.95
0.73
Apical inferior
–17.40
±
3.73
–17.65
±
6.61
0.87
Apical anterior
–11.41
±
4.04
–12.17
±
5.90
0.62
Mid-anterior
–18.00
±
3.33
–14.97
±
6.23
0.047
Basal anterior
–22.22
±
5.04
–18.75
±
7.16
0.06
SLSC peak S (%)
Basal inferior
–21.75
±
0.35
–21.20
±
6.26
0.73
Mid-inferior
–21.18
±
3.61
–20.62
±
6.99
0.73
Apical inferior
–16.97
±
3.72
–17.34
±
7.44
0.83
Apical anterior
–10.99
±
3.97
–11.75
±
6.44
0.63
Mid-anterior
–17.72
±
3.30
–14.78
±
6.65
0.06
Basal anterior
–21.82
±
4.94
–18.35
±
7.63
0.07
SLSC peak P (%)
Basal inferior
0.33
±
0.49
0.62
±
1.034
0.23
Mid-inferior
0.06
±
0.18
0.52
±
1.98
0.27
Apical inferior
0.46
±
0.66
1.03
±
3.14
0.39
Apical anterior
0.65
±
1.11
1.01
±
2.53
0.55
Mid-anterior
0.20
±
0.52
0.55
±
1.67
0.35
Basal anterior
0.61
±
1.50
0.63
±
1.18
0.95
STSR peak P (%)
Basal inferior
30.87
±
12.70
30.60
±
11.08 0.93
Mid-inferior
24.16
±
8.65
26.84
±
9.22
0.32
Apical inferior
20.89
±
7.31
26.22
±
11.44 0.06
Apical anterior
21.55
±
13.51
29.40
±
16.40 0.09
Mid-anterior
25.47
±
23.34
35.20
±
21.54 0.15
Basal anterior
30.20
±
30.81
41.83
±
26.16 0.180
STSR peak G (%)
Basal inferior
–21.55
±
4.19
–20.82
±
6.76
0.66
Mid-inferior
–21.09
±
3.52
–20.40
±
7.23
0.68
Apical inferior
–16.92
±
3.72
–17.32
±
7.19
0.81
Apical anterior
–10.92
±
3.95
–11.73
±
6.37
0.61
Mid-anterior
–17.53
±
3.26
–14.735
±
6.58
0.07
Basal anterior
–21.61
±
5.00
–18.36
±
7.37
0.09
SLSC (ES) (%)
Basal inferior
24.62
±
16.37
25.58
±
13.77 0.83
Mid-inferior
21.18
±
10.41
24.35
±
11.35 0.33
Apical inferior
19.02
±
8.22
24.90
±
12.82 0.07
Apical anterior
18.972
±
13.33
28.12
±
17.37 0.05
Mid-anterior
19.41
±
23.34
33.33
±
22.37 0.047
Basal anterior
19.51
±
32.88
38.74
±
26.77 0.038
STSR (ES) (%)
Basal inferior
13.93
±
3.22
13.21
±
4.30
0.53
Mid-inferior
7.70
±
1.99
7.55
±
2.58
0.82
Apical inferior
2.06
±
0.97
2.14
±
1.27
0.811
Apical anterior
1.67
±
1.15
1.67
±
1.83
0.999
Mid-anterior
5.69
±
1.81
5.24
±
3.03
0.55
Basal anterior
12.19
±
2.72
10.50
±
4.68
0.14
DLDC (ES) (mm)
Basal inferior
4.40
±
1.88
4.46
±
2.09
0.91
Mid-inferior
4.07
±
1.71
3.89
±
1.83
0.72
Apical inferior
2.49
±
1.42
2.54
±
1.30
0.90
Apical anterior
1.42
±
0.94
1.64
±
1.04
0.45
Mid-anterior
2.58
±
1.57
2.5523
±
1.75
0.94
Basal anterior
5.59
±
2.74
5.00
±
2.96
0.48
SLSC peak G: the most negative peak longitudinal strain, SLSC peak S: negative
systolic peak longitudinal strain, SLSC peak P: positive systolic peak longitudinal
strain, SLSC (ES): end-systolic longitudinal strain, STSR peak P: positive peak
transverse strain, STSR peak G: the most negative peak transverse strain, STSR
(ES): end-systolic longitudinal strain, DLDC (ES): end-systolic longitudinal
displacement.