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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 178 EL-MINIA MED. BULL. VOL. 22, NO. 2, JUNE, 2011 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. 179 EL-MINIA MED. BULL. VOL. 22, NO. 2, JUNE, 2011 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. 180 EL-MINIA MED. BULL. VOL. 22, NO. 2, JUNE, 2011 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 181 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. 182 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. 183