Aggarwal Priyanka, Kumar Ishan, Jain Anubha, Verma Ashish, Gupta Vineeta
Departments of Pediatrics, Division of Pediatric Hematology Oncology.
Radiodiagnosis and Imaging, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
J Pediatr Hematol Oncol. 2020 Oct;42(7):e610-e614. doi: 10.1097/MPH.0000000000001734.
BACKGROUND/OBJECTIVES: Cardiac T2* magnetic resonance imaging (MRI) is the gold standard to determine myocardial iron overload. As availability of Cardiac T2* is not uniform across developing nations, our strategy was to identify a more accessible and cost effective tool to assess myocardial iron accumulation. As children with transfusion-dependent thalassemia also experience various electrocardiographic abnormalities, we performed electrocardiography (ECG) as well as Cardiac T2* MRI on all children registered in our thalassemia unit.
Forty-eight transfusion-dependent thalassemia children with transfusion burden ≥12 times/y (6 to 19 y) in the Thalassemia Unit of the Division of Hematology Oncology, Department of Pediatrics were enrolled. Patients were divided into 3 groups based on severity of T2* value, that is group I (T2*<10), group II (T2* 10 to 20), group III (T2*>20). A T2* value >20 was taken as normal. ECG and serum ferritin was also performed on the day of MRI.
Among the various ECG parameters, QRS duration, and QTc interval were significantly increased if cardiac iron overload was high with a P-value of 0.036 and 0.000, respectively. Also, high serum ferritin predicted a decline in T2* value with a P-value of 0.001. QT interval and QTc interval significantly correlated inversely with T2* (P=0.042, r=-0.295 and P=0.002, r=-0.446, respectively) but not QRS duration (P=0.05, r=-0.282). Serum ferritin also was found to have a significant inverse correlation with T2* value (P=0.000, r=-0.497).
Abnormalities on ECG, that is prolongation of QRS duration, QT interval, and QTc interval were significantly associated with cardiac iron overload, that is decrease in the value of Cardiac T2* in our study.
背景/目的：心脏T2磁共振成像（MRI）是确定心肌铁过载的金标准。由于发展中国家心脏T2的可及性并不统一，我们的策略是确定一种更易获取且成本效益更高的工具来评估心肌铁蓄积。由于依赖输血的地中海贫血患儿也会出现各种心电图异常，我们对在我们地中海贫血科室登记的所有患儿进行了心电图（ECG）检查以及心脏T2* MRI检查。
招募了儿科血液肿瘤学部地中海贫血科室48名输血负担≥12次/年（6至19岁）的依赖输血的地中海贫血患儿。根据T2值的严重程度将患者分为3组，即I组（T2<10）、II组（T2* 10至20）、III组（T2*>20）。T2*值>20被视为正常。在MRI检查当天还进行了心电图和血清铁蛋白检查。
在各种心电图参数中，如果心脏铁过载程度高，QRS时限和QTc间期会显著增加，P值分别为0.036和0.000。此外，高血清铁蛋白预示T2值下降，P值为0.001。QT间期和QTc间期与T2呈显著负相关（分别为P=0.042，r=-0.295和P=0.002，r=-0.446），但与QRS时限无关（P=0.05，r=-0.282）。还发现血清铁蛋白与T2*值呈显著负相关（P=0.000，r=-0.497）。
心电图异常，即QRS时限、QT间期和QTc间期延长与心脏铁过载显著相关，在我们的研究中即心脏T2*值降低。
