Pediatric Cardiology Unit, Department of Pediatrics, Hacettepe University Faculty of Medicine, 06100, Ankara, Turkey.
Int J Cardiovasc Imaging. 2010 Apr;26(4):413-21. doi: 10.1007/s10554-010-9591-6. Epub 2010 Feb 2.
Tissue Doppler imaging (TDI) can detect myocardial dysfunction related to iron load in patients with beta-thalassemia major (TM). We aimed to assess the efficacy of pulsed-wave TDI (PW-TDI) in predicting myocardial iron load in patients with TM using T2* magnetic resonance (MR) as the gold-standard non-invasive diagnostic test. 33 asymptomatic TM patients, mean aged 18 +/- 6 years (6-31) with normal left ventricular (LV) global systolic function were evaluated by conventional echocardiography and PW-TDI. Results were compared with 20 age and sex-matched controls. TDI measures included myocardial systolic (Sm), early (Em) and late (Am) diastolic velocities at basal and middle segments of septal and lateral LV wall. Myocardial iron deposition were measured in 29/33 patients by T2* MR. TM patients were also subgrouped according to those with iron load (T2* <or= 20 ms) and those without (T2* > 20 ms). Mean T2* was 12.3 +/- 7.8 ms (4-31.3). Abnormal myocardial iron load (T2* < 20 ms) was found in 25/29 (86%) patients. The following TDI measures were lower in patients than in controls: basal septal Em (P < 0.001) and Am (P < 0.05), mid-septal Am (P < 0.05), mid-lateral LV wall Sm (P < 0.05) and Am (P < 0.05). Regional myocardial dysfunction were more prominent in patients with T2* <or= 20 ms. Mid-septal Sm and Em significantly correlated with mid-septal T2*(r = 0.44, P = 0.023 and r = 0.54, P = 0.004, respectively). The PW-TDI parameters and the cut-off values for predicting presence of myocardial iron load were determined. PW-TDI technique was found both sensitive and specific in predicting presence of myocardial iron load in TM patients with normal LV global systolic function. Therefore, it can be used for screening of TM patients.
组织多普勒成像（TDI）可检测到重型β地中海贫血（TM）患者铁负荷相关的心肌功能障碍。我们旨在评估脉冲波 TDI（PW-TDI）在使用 T2磁共振（MR）作为金标准的无创诊断测试预测 TM 患者心肌铁负荷方面的疗效。对 33 例无症状的 TM 患者（平均年龄 18 ± 6 岁，年龄 6-31 岁）进行了常规超声心动图和 PW-TDI 检查。将结果与 20 名年龄和性别匹配的对照组进行比较。TDI 测量包括左心室（LV）室间隔和侧壁基底段和中段心肌收缩期（Sm）、早期（Em）和晚期（Am）舒张速度。29/33 例患者采用 T2MR 测量心肌铁沉积量。TM 患者还根据铁负荷（T2*≤20ms）和无铁负荷（T2*>20ms）进行了亚组分析。平均 T2为 12.3±7.8ms（4-31.3）。29/29 例（86%）患者存在异常心肌铁负荷（T2<20ms）。与对照组相比，患者的以下 TDI 指标较低：基底段室间隔 Em（P<0.001）和 Am（P<0.05）、中段室间隔 Am（P<0.05）、中段侧壁 LV 壁 Sm（P<0.05）和 Am（P<0.05）。T2*≤20ms 的患者区域性心肌功能障碍更为明显。中段室间隔 Sm 和 Em 与中段室间隔 T2*显著相关（r=0.44，P=0.023 和 r=0.54，P=0.004）。确定了预测心肌铁负荷存在的 PW-TDI 参数和截断值。PW-TDI 技术在预测具有正常 LV 整体收缩功能的 TM 患者心肌铁负荷存在方面既敏感又特异。因此，它可用于 TM 患者的筛查。
