Evaluation of QT dispersion in β thalassaemia major patients

Ülger, Zülal; Aydınok, Yeşim; Levent, Ertürk; Gürses, Dolunay; Özyürek, Arif Ruhi

doi:10.1002/ajh.20679

Cited by 25 publications

(36 citation statements)

References 23 publications

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“…The exact mechanism of PD prolongation in these clinical conditions is not well known, but it is thought that structural and electrophysiological changes in the atrial myocardium caused by elevated plasma volume [28], ventricular diastolic dysfunction [29] and enhanced neurohormonal activation [30], that accompany these diseases, may contribute to left atrial enlargement and electrical instability. In literature, there are few studies about the electrocardiographic markers for the early detection of cardiac disease in patients with b-TM [31][32][33][34]. Nisli et al [13] showed an increased PD in b-TM children and supposed it could be related to depression of intra-atrial conduction due to atrial dilatation and increased sympathetic activity; however, their study presented some limitations: the restrictive diastolic filling pattern of b-TM patients and the lack evaluation of atrial dimension and iron deposition by cardiac magnetic resonance or tissue Doppler imaging.…”

Section: Discussionmentioning

confidence: 99%

Early electrocardiographic evaluation of atrial fibrillation risk in beta-thalassemia major patients

et al. 2011

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Although previous studies have documented a variety of electrocardiogram abnormalities in beta-thalassemia major (β-TM), little is known about P-wave dispersion (PD), an independent risk factor for development of atrial fibrillation. The aim of our study was to evaluate PD in β-TM patients with conserved systolic and diastolic functions. The study involved 40 β-TM patients (age 37.5 ± 10.2; 33 M) and 40 healthy subjects used as controls, matched for age and gender. PD was carefully measured using a 12-lead electrocardiogram. Cardiac iron levels were measured by cardiac magnetic resonance T2 star (CMR T2*) imaging. Comparing to the healthy control group, β-TM group presented increased values of the PD (40.1 ± 12.9 vs. 24 ± 7 ms; P < 0.004) and decreased CMR T2* imaging (29 ± 15 vs. 55 ± 13 ms; P = 0.03). We found a significant correlation between PD and CMR T2* values. Our study showed a significant increase of PD in β-TM patients with conserved systolic and diastolic cardiac functions. Our results indicate that PD is correlated to myocardial iron deposit, as assessed by CMR T2* imaging.

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Section: Discussionmentioning

confidence: 99%

Early electrocardiographic evaluation of atrial fibrillation risk in beta-thalassemia major patients

et al. 2011

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“…40 Thus, in thalassaemia patients the atherogenic process could be enhanced in part by the increased iron stores and the induced oxidative status, and in part counterbalanced by the reduced level of cholesterol; however, the final balance probably promotes increased arterial disease.…”

Section: Implications and Clinical Effectsmentioning

confidence: 99%

Hypocholesterolaemia in Thalassaemia – Pathogenesis, Implications and Clinical Effects

Ricchi¹,

Ammirabile²,

Maggio³

2010

European Oncology &Amp; Haematology

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Free cholesterol is a constituent of cell membranes. Apart from nucleus-free erythrocytes, all cells of the human body are able to synthesise cholesterol de novo. More than 100 enzymatic processes are involved in the complete biosynthesis of cholesterol, which is a complex and energy-consuming process.For this reason, several tissues prefer to assume cholesterol from plasma lipoproteins rather than from their own intracellular synthesis.Cholesterol devoted to plasma lipoprotein is synthesised in the liver and in the distal part of the small intestine.1 Chylomicron remnants are the vehicle of cholesterol intake from the diet to the liver. The hepatic cholesterol pools originating from chylomicron remnants and de novo synthesised cholesterol are combined and excreted as verylow-density lipoprotein (VLDL). Low-density lipoprotein (LDL), the ultimate catabolic product of VLDL, is the main source of cholesterol for human tissue, especially those with high cell turnover. Cholesterol is not only a fundamental element of cell membranes but also the principal precursor for steroid and sexual hormone biosynthesis. Furthermore, cholesterol, through its intermediary products such as farnesyl diphosphate and geranylgeranyl diphosphate, is involved in the regulation of ras-protein intracellular signal transduction.1 Hypercholesterolaemia in ThalassaemiaA large body of evidence from prospective and retrospective studies has clearly shown that patients affected by thalassaemia have reduced levels of TC with respect to healthy age-and sex-matched controls. 3-10Hypocholesterolaemia has been reported in all phenotypes of β-thalassaemia and has also been described in various haematological disorders associated with high erythropoietic activity.11-14 Table 1 shows cholesterol levels found in different reports exploring lipid profiles in young and adult patients affected by all phenotypes of thalassaemia.The majority of these studies have evaluated cholesterol level in young patients with severe thalassaemia (thalassaemia major and intermedia). As shown in Table 1, low levels of plasma cholesterol are evident among all ages of patients with thalassaemia major and intermedia.Almost all studies agree with the observation that of all the forms of thalassemia, thalassaemia intermedia patients show the most marked alterations in lipid profile. Conversely, no studies have identified a cholesterol cut-off value that could clearly distinguish patients with thalassaemia intermedia from those affected by thalassaemia major.Furthermore, hypocholesterolaemia is only one aspect in the more complex alteration of lipid profile involving LDL and HDL level observed in all thalassemia patients. In fact, most of the abovementioned studies reported that thalassaemia patients also have lower HDL and LDL levels than those observed in control patients.Many of these studies have also tried to identify within-patient factors correlating with cholesterol level; 4,8,9 data analysis of most reported studies failed to show any influence on cholesterol level of a...

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“…Echocardiography is a useful and noninvasive diagnostic tool for diagnosis of heart disorders and helps with early detection of heart failure before the development of symptoms. As a result, it is possible to initiate early treatment (6). It seems that electrocardiography (ECG) is a suitable alternative tool in this regard and has an acceptable test values in comparison with echocardiography (6).…”

Section: Introductionmentioning

confidence: 99%

“…As a result, it is possible to initiate early treatment (6). It seems that electrocardiography (ECG) is a suitable alternative tool in this regard and has an acceptable test values in comparison with echocardiography (6). Based on previous studies, QTcd and QTd indices are good parameters in this regard.…”

Section: Introductionmentioning

confidence: 99%

Comparison of QT Dispersion With Left Ventricular Mass Index in Early Diagnosis of Cardiac Dysfunction in Patients With β-Thalassemia Major

Noori

Mahjoubifard

Mohammadi

et al. 2014

Iran Red Crescent Med J

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Background:In electrocardiography (ECG), QT is the interval between the onset of Q wave to the end of the T wave. This interval may be a sign of changes in the ventricular structure in hematologic disorders such as thalassemia major.Objectives:The main goal of this study was to compare the diagnostic value of corrected QT dispersion (QTcd) and QT dispersion (QTd) with left ventricular mass (LVM) and left ventricular mass index (LVMI) as well as to determine their sensitivity and specificity in early detection of the cardiac involvement in patients with β-thalassemia major.Patients and Methods:In a case-control study, 60 patients older than ten years of age with thalassemia major who received regular blood transfusion and iron chelators were selected as the case group and were compared with 60 healthy age- and sex-matched subjects. All patients had myocardial performance index (MPI) of more than 0.5 and MPI for controls was less than 0.5. Echocardiography and ECG were performed for both groups and data were analyzed using appropriate statistical tests.Results:The mean age of cases and controls were 16 ± 2.8 and 16.08 ± 3.01 years, respectively. Male to female ratio was 33:27 in case group and 31:29 in the control group. LVMI in the case group was greater than control group. QTd and QTcd were larger in case group than in control group. The sensitivity and specificity of LVM, LVMI, QTd, and QTcd were as follows: 88.3%, 77.1%; 86.7%, 80%; 93.8%, 80%; and 91.7%, 86.7%, respectively.Conclusions:This study showed acceptable sensitivity and specificity of QTcd and QTd in comparison to LVMI; it seems that standard ECG can be used for early diagnosis of cardiac involvement in asymptomatic patients with thalassemia major.

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Evaluation of QT dispersion in β thalassaemia major patients

Cited by 25 publications

References 23 publications

Early electrocardiographic evaluation of atrial fibrillation risk in beta-thalassemia major patients

Early electrocardiographic evaluation of atrial fibrillation risk in beta-thalassemia major patients

Hypocholesterolaemia in Thalassaemia – Pathogenesis, Implications and Clinical Effects

Comparison of QT Dispersion With Left Ventricular Mass Index in Early Diagnosis of Cardiac Dysfunction in Patients With β-Thalassemia Major

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