PURPOSE: Ventricular repolarization is assessed using the QT interval corrected by the heart rate (QTc) via an electrocardiogram (ECG). Prolonged QTc is associated with an increased risk of @entity943 and cardiac mortality. As there have been few reports regarding the effects of @entity1378 on ventricular repolarization, we studied the association between serum free @entity1955 (free T4 [fT4]) and thyroid stimulating hormone (TSH) levels and the QTc interval. METHODS: Thirty-eight @entity1 with @entity1378 (<30 years old) were included, and we used their clinical records and available ECGs (between August 2003 and August 2011) to evaluate the association between their fT4 and TSH levels and their QTc interval. In addition, we studied the ECGs of 72 age-matched @entity1 with no @entity1378 (control group) and compared their data with that from the @entity1 group. RESULTS: The QTc duration in @entity1 with @entity1378 was significantly prolonged compared to that in the control subjects (P<0.001). In addition, the number of @entity1378 @entity1 with abnormal prolonged QTc was significantly higher than that in the control group (P<0.001). Among the @entity1 with @entity1378 , @entity1 with prolonged QTc and borderline QTc had higher fT4 levels and there was positive correlation between their fT4 levels and their QTc interval (P<0.05). However, no correlation was observed between their TSH levels and their QTc interval. CONCLUSION: We report that @entity1378 is associated with @entity1162 . The correlation between the fT4 levels and the QTc interval suggests that thyroid status is associated with QTc values and the risk of cardiac mortality.

The XXXX in @entity1378 and the association of thyroid hormone with the QTc interval.

@entity1 :: ('9606', 'Species') :: ['patients'] @entity1955 :: ('MESH:D013974', 'Chemical') :: ['thyroxine'] @entity1378 :: ('MESH:D006980', 'Disease') :: ['hyperthyroidism', 'hyperthyroid'] @entity1162 :: ('MESH:D008133', 'Disease') :: ['QTc prolongation'] @entity943 :: ('MESH:D001145', 'Disease') :: ['arrhythmias']
@entity1162 :: (MESH:D008133,Disease) :: ['corrected QT (QTc) prolongation']
