Detection of Early Right Ventricular Dysfunction in Young Patients With Thalassemia Major Using Tissue Doppler Imaging

Feasibility study on evaluating right ventricular diastolic function by new Tei'-Index

Objective

Doppler-derived myocardial performance index (Tei) has been used in the evaluation of right ventricular (RV) function. However, the usage in isolated diastolic dysfunction is limited.We sought to find a new Tei'-index that is more appropriate for evaluating isolated diastolic dysfunction (IDD) based on the symmetry of cardiac structure and function.

Methods

21 patients with impaired RV relaxation were compared to 44 control subjects. Tei and Tei' including their components, isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), the ejection time (ET), and RV rapid filling time (RFT) were measured from RV outflow and tricuspid inflow Doppler velocity profiles.

Results

Tei-index have no change between IDD group and control subjects (0.21 ± 0.08 vs 0.23 ± 0.07 P[bond, double bond]NS). The Tei'-index was significantly shortened in IDD group(0.24 ± 0.09 vs 0.32 ± 0.12,p＜0.05).The decrease in Tei'-index was due to the prolongation of both IRT and RFT, and in the abbreviation of ICT. Tei'-index cutoff value of ≥0.31 identified impaired RV relaxation with a sensitivity of 50 % and specificity of 86 %.We also find that the Tei'-index correlated well with doppler measures of diastolic parameters like E/A, E/e', DT, which suggests its potential use as a noninvasive indicator of the right ventricular (RV) relaxation in patients with heart failure of different causes.

Conclusion

New Tei's index is highly effective and specific in the evaluation of early diastolic dysfunction of right ventricle, and can be used as an indicator for the detection of IDD in clinic.

Assessment of Cardiac Functions and Arrhythmia in Children with Beta-Thalassemia Major and Beta-Thalassemia Intermedia

BACKGROUND: Heart disease is a major complication in thalassemic patients. Heart injuries in iron overload cases include arrhythmia, pulmonary hypertension, systolic/diastolic dysfunction, and heart failure. AIM: This study aimed to assess cardiac functions and arrhythmia in children with β-thalassemia major (TM) and β-thalassemia intermedia (TI) and its relation to cardiac iron overload. METHODS: Thirty β-TM patients and 30 β-TI patients were evaluated using echocardiography and 24-h ambulatory electrocardiogram monitoring (Holter). Among these patients, 15 β-TM and 15 β-TI patients were evaluated using cardiac magnetic resonance imaging T2* by single breath-hold multi-echo technique. RESULTS: Arrhythmia was detected significantly more in β-TM patients than β-TI (p = 0.049). Nine (30%) β-TM and five (16.6%) β-TI patients had Sinus tachycardia. Two (6.7%) β-TM patients compared to one (3.33%) β-TI patient had supraventricular tachycardia runs. Three (10%) β-TM and one (3.33%) β-TI patient had extreme sinus tachycardia. Two (3.3%) β-TI patients had sinus bradycardia, while two (3.3%) β-TM patients had incomplete Right bundle branch block. Regarding echo parameters: Isovolumic relaxation time (IVRT), Left ventricle myocardial performance index (MPI LV), Right ventricle myocardial performance index (MPI RV) and end systolic pulmonary artery pressure, were significantly higher in β-TM than TI group (p < 0.05). Fractional shortening, Ejection fraction were significantly lower in β-TM than TI group (p < 0.001). A statistically significant negative correlation was found between cardiac T2* and each of (IVRT, MPI LV, MPI RV) (p ˂ 0.05). CONCLUSION: Arrhythmias are more common in the β-TM group. Systolic, diastolic dysfunction and high pulmonary pressure are more prevalent in TM than in TI. Global myocardial performance is more impaired in TM than in TI patients. Iron overload has a deleterious effect on cardiac function.

Iron Overload in Transfusion-Dependent Indonesian Thalassemic Patients

Thalassemia is a genetic disease caused by disruption of globin chain synthesis leading to severe anemia and thus regular blood transfusion is necessary. However, there have been known transfusions-related consequences, including iron overload and multi-organ damage. The aims of this study were to evaluate liver and cardiac function in youth and adult transfusion-dependent Indonesian thalassemic patients and to assess its correlation with serum ferritin levels, as well as T2 ^∗ magnetic resonance imaging (MRI). Transfusion-dependent thalassemic (TDT) outpatients (n = 66; mean age, 21.5 ± 7.2 years) were carried out for the complete assessment consisting of blood test including liver enzyme and serum ferritin, followed by electrocardiography (ECG) and echocardiography. Subjects were also divided by serum ferritin levels into three groups: < 2500 ng/mL, 2500-5000 ng/mL, and >5000 ng/mL. Additionally, subgroup analysis in patients with T2^∗ MRI assessment was conducted. In terms of age of first blood transfusion, subjects with ferritin >5000 ng/mL were the youngest among others. The alanine aminotransferase (ALT) levels in group with serum ferritin >5000 ng/mL were significantly higher than those of the group with serum ferritin <2500 ng/mL. Additionally, youth and adult TDT patients whose serum ferritin >5000 ng/mL had significantly lower tricuspid annular plane systolic excursion (TAPSE) when compared with those who had serum ferritin <2500 ng/mL. Similarly, TAPSE in patients with moderate cardiac siderosis based on cardiac T2^∗ MRI was significantly lower than those without cardiac siderosis. There was significant, but only moderate correlation between serum ferritin and cardiac T2^∗ MRI. Based on these findings, it is important to routinely monitor iron accumulation-related complications, including liver and cardiac damage in youth and adult TDT patients.

Evaluation of myocardial perfusion and function in patients with asymptomatic beta-thalassemia major using myocardial gated single-photon-emission computed tomography

This study was conducted to evaluate the cardiac perfusion and function of patients with beta-thalassemia major (TM) using^99mTc-MIBI cardiac gated single-photon-emission computed tomography (SPECT) and to compare the obtained indices with echocardiographic and hematological parameters. Patients with TM who were referred for regular blood transfusion and periodic checkup were included in this study. A questionnaire containing demographic and medical data was provided for all patients by an expert pediatrician. All of the patients were on Desferal chelation therapy and none of them had clinical signs of heart failure. Myocardial gated perfusion SPECT, echocardiography, and complete blood tests were performed for each patient. In total, 24 patients including 14 men (58.3%) and 10 women (41.7%) aged 15-36 years with a mean age of 24.3 ± 6.5 years' old were enrolled in this study. Myocardial perfusion scan (MPS) was normal in all patients. The mean value of the measured left ventricular ejection fraction (LVEF) was 58.88 ± 13.45%. There was no significant association between measured LVEF on scan and echocardiography (P > 0.05). In terms of hematological results, there was a significant association between the hemoglobin and ferritin level and the amount of blood transfusion (P = 0.02 and P= 0.00, respectively). According to the results of myocardial perfusion imaging (MPI), cardiac perfusion and LVEF were within normal limits in all asymptomatic patients. In the absence of any perfusion abnormality, the use of MPI in patients with asymptomatic beta-TM is not recommended for diagnosing myocardial ischemia.

Determining Nt-proBNP Levels with Diastolic Dysfunction in Thalassemia Major Patients

Beta thalassemia is an autosomal, recessive disorder, characterized by ineffective erythropoiesis. Chronic transfusions and inability of body to eliminate iron lead to an iron overload, thereby causing damage to heart. Natriuretic peptides (NPs) are produced within the heart, which are then released into the circulation in response to ventricular wall stress. We, therefore, aimed to study the relation between ventricular dysfunction and N-terminal pro-B-type natriuretic peptides (NT-proBNPs). We enrolled 105 patients with increased serum ferritin levels and echocardiography was performed. We collected blood samples and NT-proBNP levels were measured in them. Though we found that the studied group had no significant difference in the mean serum NT-proBNP levels, in patients with or without hypertrophy ( n  = 37, p  = 0.992), the NT-proBNP levels were found to be significantly increased in patients with diastolic dysfunction ( n  = 24, p  < 0.0001 with mean values of 577.67 ± 122.01 and 456.50 ± 48.40 pg/mL in patients with and without diastolic dysfunction, respectively). The NT-proBNP levels correlated well with the echocardiography indices, such as left ventricular end-systolic diameter (LVESD), ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/E' ratio), and ratio of the early (E) to late (A) ventricular filling velocities (E/A ratio), and were found to have significant positive correlation with the serum ferritin levels. The NT-proBNP levels correlated significantly with diastolic dysfunction; thus, serum ferritin levels could be useful for assessing the diastolic dysfunction in patients with beta thalassemia.