Liem Robert I, Young Luciana T, Thompson Alexis A
Division of Hematology, Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
Pediatr Blood Cancer. 2009 Jul;52(7):842-6. doi: 10.1002/pbc.21973.
Prolongation of the QTc interval may be more common than previously believed among individuals with sickle cell disease (SCD). The clinical associations and natural history of QTc prolongation remain unclear in this population. Our objectives were to determine the prevalence of prolonged QTc and evaluate its relationship to clinical factors in children and young adults with SCD.
We analyzed data from subjects 10 to 25 years old with SCD enrolled in our pulmonary hypertension screening protocol. Screening included echocardiography (ECHO), 12-lead electrocardiogram (ECG) and laboratory testing at steady state. QTc interval >440 msec was considered prolonged.
ECG data from 76 subjects (57% male, mean age 14.2 +/- 3 years old, range 10-24) were analyzed. We observed prolonged QTc in 29/76 (38%) subjects. Despite evidence of left ventricular hypertrophy (LVH) in 50/76 (66%) subjects, the frequency of LVH was not significantly different in subjects with and without QTc prolongation. When compared to subjects with normal QTc, subjects with prolonged QTc had higher mean tricuspid regurgitant jet velocity (2.51 +/- 0.27 m/sec vs. 2.33 +/- 0.26 m/sec, P = 0.010) as well as higher mean lactate dehydrogenase (433 +/- 142 IU/L vs. 343 +/- 142 IU/L, P = 0.000) and aspartate aminotransferase (48 +/- 20 IU/L vs. 39 +/- 15 IU/L, P = 0.026). A larger proportion of subjects with prolonged QTc also had a history of recurrent acute chest syndrome (66% vs. 38%, P = 0.038).
We conclude that QTc prolongation is a frequent finding in SCD not associated with LVH. Elevated pulmonary pressures, hemolysis and acute chest syndrome may represent risk factors for prolonged QTc in this population.
在镰状细胞病（SCD）患者中，QTc间期延长可能比之前认为的更为常见。在这一人群中，QTc间期延长的临床关联和自然病史仍不清楚。我们的目标是确定QTc延长的患病率，并评估其与SCD儿童和青年临床因素的关系。
我们分析了纳入我们肺动脉高压筛查方案的10至25岁SCD患者的数据。筛查包括超声心动图（ECHO）、12导联心电图（ECG）以及稳态下的实验室检测。QTc间期>440毫秒被视为延长。
分析了76名受试者（57%为男性，平均年龄14.2±3岁，范围10 - 24岁）的心电图数据。我们观察到29/76（38%）的受试者QTc延长。尽管76名受试者中有50名（66%）有左心室肥厚（LVH）的证据，但QTc延长和未延长的受试者中LVH的发生率无显著差异。与QTc正常的受试者相比，QTc延长的受试者平均三尖瓣反流射流速度更高（2.51±0.27米/秒对2.33±0.26米/秒，P = 0.010），平均乳酸脱氢酶也更高（433±142国际单位/升对343±142国际单位/升，P = 0.000）以及天冬氨酸转氨酶更高（48±20国际单位/升对39±15国际单位/升，P = 0.026）。QTc延长的受试者中也有更大比例有复发性急性胸综合征病史（66%对38%，P = 0.038）。
我们得出结论，QTc延长在SCD中是常见现象，与LVH无关。肺动脉压力升高、溶血和急性胸综合征可能是该人群QTc延长的危险因素。
