Download EL-MINIA MED. BULL. VOL. 22, NO. 2, JUNE, 2011 Sayed et al

EL-MINIA MED. BULL. VOL. 22, NO. 2, JUNE, 2011
Sayed et al
TISSUE DOPPLER IMAGING (TDI) AND ELECTROCARDIOGRAPHY
RELIABILITY IN PREDICTING SEVERITY OF MYOCARDIAL SIDEROSIS
IN SPLENECTOMIZED ß-THALASSEMIC CHILDREN.
By
Samira Zein Sayed*, Basma Abd El-Moez Ali*, Amr Salah Amin**,
Abd El-Hakim Abd El-Mohsen Abd El-Hakim* and Suzan Mohamed Aly Omar*
Departments of *Pediatrics and **Cardiology, El-Minia University.
ABSTRACT:
Background: An important complication of β- thalassemia major is myocardial
siderosis. The potential role of spleen in iron metabolism rises the concern about
effect of splenectomy on myocardial dysfunction resulting from myocardial siderosis.
Aim: To evaluate cardiac function in patients with β-thalassemia major who had
undergone splenectomy.
Patients and methods :56 patients (pts) with β-thalassemia major and Transfusion
burden ≥ 12 times/ year aged 6-16 years were included in our study and were
classified into two groups according to serum ferritin, Group Ι:consisted of 21
splenectomized, Group II: consisted of 35 non splenectomized pts. They were
subjected to thorough history taking, routine laboratory investigations and serum
ferritin level, ECG{corrected QT intervals (QTc) and QT dispersion (QTd)},
echocardiography, Left atrial (LA) volumes, Systolic and diastolic functions of LV
using standard and tissue Doppler imaging (Peak systolic wave, Q-S peak duration,
peak and late diastolic waves) .
Results: The study showed that the splenectomized group had significant higher E/A
ratio at the septum and the lateral wall where (P= 0.01, 0.04) respectively. Also, they
had a significant lower DT at mitral valve, the lateral wall and the right ventricle
where (P= 0.02) for each of them. Moreover, splenectomized group had significant
higher peak S wave at the septum where (P= 0.04) and a significant longer Q-S
duration at the septum and the right ventricle where (P= 0.03) for each. Also, the
splenectomized group had a significant increase in LAV min and a significant lower
LA-EF% where (P=0.04, 0.01) respectively QTc, QTd and systolic dysfunction
evaluation by standard echo showed insignificant differences where P>0.05.
Conclusion: Splenectomized patients had more profound myocardial dysfunction,
which might be explained by that the spleen has a role in iron regulation. This further
increase in myocardial dysfunction after splenectomy in thalassemia should be borne
in mind when considering removal of this organ.
KEYWORDS:
β-thalassemia major
Splenectomy
Tissue Doppler
included: transfusion of red blood
cells, chelation, splenectomy. This
triad is now been disputed, as spleenectomy, still necessary in some
extreme cases, has been shown to be
preventable with the appropriate
transfusional therapy. The role of
spleenectomy in worsening iron
INTRODUCTION:
An important complication of
β- thalassemia major is iron deposition
in cardiac tissue resulting in
degeneration, fibrosis and dysfunction1. Cardiac disease is the primary
cause of death2. The treatment of
thalassemia major has traditionally
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overload is uncertain. It is often
suggested that the spleen could represent a safe reservoir for the transfused
iron and that splenectomy would,
therefore, favour a more massive
accumulation of iron in the other body
organs3. In the past, splenectomy was
performed shortly after diagnosis
because the spleen soon became every
large and severe hypersplenism
ensued4. In several studies, Tissue
Doppler imaging have been used to
evaluate ventricular dysfunction in
thalassemic patients.5 Also, many of
the previous data support that QT
dispersion reflects regional variation in
ventricular recovery6.
rheumatic,
failure…etc).
Sayed et al
congenital,
heart
The studied groups were
subjected to; Thorough history taking,
clinical examination and electrocardiography (ECG) was performed; QT
dispersion (QTd) was defined as the
difference between the longest and
shortest QT intervals. QT intervals
were corrected by heart rate according
to Bazett’s formula (QTc = QT/√RR)7.
Finally, standard Echocardiography &
Tissue Doppler Imaging (TDI); E/A
ratio was calculated. Also deceleration
time (DT) was measured. Ejection
fraction (EF) was obtained by M-mode
approach8. Left atrial (LA) volumes
was measured. Three major velocities
were recorded: the positive systolic
velocity (S) and 2 negative diastolic
velocities (one during the early phase
of diastole (Ea) and another in the late
phase of diastole (Aa). Time elapsed
from the inscription of the Q-wave on
the surface EGG to the peak of the Swave (Q-S peak) in PTD were
determined9. The peak value of the Swave and the Q-S peak duration were
taken as determinants of systolic function. E/A ratio and DT were taken as
determinants of diastolic function.
AIM OF THE WORK :
To evaluate cardiac function in
patients with β-thalassemia major who
had undergone splenectomy.
PATIENTS AND METHODS:
Our study was carried out on
56 patients with β-thalassemia major
who had regular follow up in pediatric
hematology outpatient's clinic, children
university hospital, Minia University
from February 2009 to April 2011.For
the purpose of this study patients were
classified into the following 2 groups:Group Ι included 21 splenectomized
patients, Group II included 35 patients
not splenectomized.
STATISTICAL METHODOLOGY:
Standard computer program
SPSS for windows, release 13.0 (SPSS
Inc, USA) was used for data entry and
analysis. All numeric variables were
expressed as mean ± standard deviation (SD). Comparison of different
variables in various groups were done
using student t-test. A significant Pvalue was considered when P-value
was less than 0.0513
Inclusion criteria: Age between 6 to
16 years old, Transfusion burden ≥ 12/
year, Last blood transfusion was less
than 4 days ago.
Exclusion criteria: Patients younger
than 6 years old,Transfusion burden <
12/year, any cardiac disease e.g.
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Sayed et al
RESULTS:
Table (1): Comparison between splenectomized and non splenectomized patients as
regarding ECG findings.
Splenectomized
NO (21)
376.75±34.38
Non splenectomized
NO (35)
281.17±46.76
P -value
39±10.88
0.49
QTc
mean±SD
(ms)
41.17±12.2
QTd
mean±SD
(ms)
QTc: corrected QT interval; QTd: QT dispersion.
This table showed insignificant
differences between the two groups as
0.68
regarding QTc and QTd where (P>
0.05).
Table (2): Comparison between splenectomized and non splenectomized patients as
regarding diastolic function by standard echo and TDI.
Mitral : E/A
DT(ms)
Splenectomized
NO (21)
(mean ±SD)
1.97±0.48
141.33±36.04
Non splenectomized
NO (35)
(mean ±SD)
1.82±0.32
147.85±27.86
Tricuspid: E/A
DT(ms)
1.86±0.35
143.85±36.75
1.83±0.36
148.6±28.6
0.69
0.59
Septum: E/A
DT(ms)
1.79±0.64
135.71±31.59
1.93±0.31
145.91±26.32
0.01*
0.19
Lat. wall: E/A
DT(ms)
2.23±1.07
130.9±32.67
1.97±0.422
147.97±23.96
0.04*
0.02*
RV:
2.34±0.95
127.85±29.85
2.02±0.56
145.14±25.87
0.11
0.02*
E/A
DT(ms)
P-value
0.16
0.02*
E/A: ratio of peak flow velocity in early diastole to peak flow velocity in late diastole;
DT: flow velocity deceleration time.
*Significant
The previous table showed
the
splenectomized
group
significant higher E/A ratio at
septum and the lateral wall where
that
had
the
(P=
0.01, 0.04) respectively. Also, they had
a significant lower DT at mitral valve,
the lateral wall and the right ventricle
where (P= 0.02) for each of them.
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Sayed et al
Table (3): Comparison between splenectomized and non splenectomized patients as
regarding systolic function by standard echo and TDI.
Splenectomized Non splenectomized
NO (21)
NO (35)
(mean ±SD)
(mean ±SD)
67.52±4.77
65.8±5.57
EF%
P-value
0.24
FS%
36.09±3.17
35.28±4.61
0.48
Septum: -Peak S wave(cm/s)
-Q-S duration(ms)
7.26±0.77
155.33±9.61
7.24±0.76
152.54±13.43
0.04*
0.03*
Lat. wall: -Peak S wave(cm/s)
-Q-S duration(ms)
RV:
-Peak S wave(cm/s)
-Q-S duration(ms)
7.31±0.74
139.95±6.89
7.53±0.7
139.91±8.75
0.98
0.21
7.12±0.91
152.57±11.05
EF: ejection fraction; FS: fractional shortening.
*Significant
7.27±0.86
149.57±11.97
0.53
0.03*
This table showed that splenectomized group had significant higher
peak S wave at the septum where (P=
0.04) and a significant longer Q-S
duration at the septum and the right
ventricle where (P= 0.03) for each.
Table (4): Comparison between splenectomized and non splenectomized patients as
regarding left atrial emptying function.
LA
LAVp (mm)
LAV min (mm)
LA-EF%
Splenectomized
NO (21)
(mean ±SD)
Non splenectomized
NO (35)
(mean ±SD)
P-value
98.1±9.49
57.27±5.87
41.43±4.85
95.69±7.86
53.97±5.57
45.47±4.8
0.3
0.04*
0.01*
LAVp: peak left atrial volume; LAVmin: minimum left atrial volume;
LA-EF: left atrial ejection fraction.
*Significant
The previous table showed that
the splenectomized group had a
significant increase in LAV min and a
significant lower LA-EF% where
(P=0.04, 0.01) respectively.
failure due to a cardiomyopathy associated with iron over-load. Aggressive
chelation therapy may prevent, delay
or even reverse myocar-dial dysfunction, but once overt heart failure is
present only 50% of patients survive 10.
DISCUSSION:
Life expectancy in patients
with thalassaemia major is still limited
by development of congestive heart
Concerning the evaluation of
the role of splenectomy on myocardial
siderosis, our study revealed that
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EL-MINIA MED. BULL. VOL. 22, NO. 2, JUNE, 2011
splenectomized patients had significant
more profound cardiac dysfunction
than patients who did not undergone
splenectomy.
Sayed et al
CONCLUSION:
Splenectomized patients had
more profound myocardial dysfunction, which might be explained by
that the spleen has a role in iron
regulation. This further increase in
myocardial dysfunction after splenectomy in thalassemia should be borne in
mind when considering removal of this
organ.
Our results were in agreement
with the results obtained by Aydinok et
al. who found a higher incidence of
myocardial siderosis in splenectomized
patients compared with those who had
not, as they had significantly higher
myocardial iron content than non
splenectomized patients. This higher
myocardial iron content in splenectomized patients might be explained by
that the spleen has a role in iron
regulation11.
REFERNCES:
1. Olivieri NF. The b-thalassemias.
N Engl J Med 1999;341:99–109.
2. Modell B, Khan M, Darlison M.
Survival in beta-thalassemia major in
UK: data from the UK Thalassemia
Register. Lancet 2000;355:2051–2.
3. Pecorari L., Savelli A., Della
Cuna C. and Borgna-Pignatti S. The
role of splenectomy in thalassemia
major. An update. Acta Pediatrica
Mediterranea, 2008, 24: 57.
4. Fonseca SF, Kimura EY,
Kerbauy J: Assessment of iron status
in individuals with heterozygotic βthalassemia. Rev Assoc Med Bras,
1995; 41 (3): 203- 206 .
5. Lau KC, Li AM, Hui PW,
Yeung CY. Left ventricular function in
beta-thalassemia major. Arch Dis
Child 1989;64:1046– 51.
6. Day CP, McComb JM,
Campbell RW: QT dispersion in sinus
beats and ventricular extrasystoles in
normal hearts. BHJ, 1992; 67: 39-41.
7. Bazett HC. An analysis of the
time–relations of electrocardiograms.
Heart. 1920;7:353.
8. Quinones MA, Otto CM,
Stoddard M, et al: "Recommendations
for quantification of Doppler echocardiography: a report from the
Doppler Quantification Task Force of
the Nomenclature and Standards
Committee of the American Society of
Echocardiography". J Am Soc Echocardiography 2002; 15: 167- 84.
Pecorari et al., suggested that
the spleen could represent a safe
reservoir for the transfused iron and
that splenectomy would, therefore,
favour a more massive accumulation of
iron in the other body organs3.
However, the iron content of the
spleen, at splenectomy, is low, amounting to no more than one fifth to one
tenth of the liver iron content. In
addition, no difference has been
observed, in terms of liver fibrosis,
between splenectomized and non
splenectomized patients12.
On the other hand, the levels of
transferring saturation, serum ferritin
and desferrioxamine-induced urinary
iron excretion were significantly
higher in splenectomized than in nonsplenectomized patients, indicating
that the spleen could have a role in the
regulation of iron metabolism3. Also,
Kadimova’s study revealed that
splenectomy has a positive effect on
iron balance and that splenectomy in
thalassemia is associated with increased iron deposition and increased
transferrin iron saturation13.
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EL-MINIA MED. BULL. VOL. 22, NO. 2, JUNE, 2011
9. Akdemir O, Dagdeviren B,
Yildiz M, Gül C, Sürücü H and Özbay
G. Specific Tissue Doppler Predictors
of Preserved Systolic and Diastolic
Left Ventricular Function after an
Acute Anterior Myocardial Infarction,
Japanese Heart Journal 2003; 44(3),
347-355.
10. Hoffbrand AV. Diagnosing
myocardial iron overload. Eur Heart J
2001; 22:2140–1.
11. Aydinok Y, Bayraktaroglu S,
Yildiz D and Alper H.: Myocardial
iron loading in patients with
Sayed et al
thalassemia major in Turkey and the
potential role of splenectomy in
myocardial siderosis. J Pediatr
Hematol Oncol. 2011 Jul; 33(5):374-8.
12. Borgna-Pignatti C., De Stefano
P. and Bongo IG. Spleen iron content
is low in thalassemia. Am J Pediatr
Hematol/Oncol 1984; 340-6.
13. Kadimova E. Peculiarities of
iron metabolism in patients with Beta thalassemia at different periods after
splenectomy. Georgian Med News.
2007 Nov; 152:35-7.
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