T wave and ST segment amplitude changes in the supine and standing electrocardiograms of children with orthostatic hypertension and their clinical significance

Abstract:

Objective To examine the changes in T wave and ST segment amplitude in the supine and standing electrocardiograms (ECG) of children with orthostatic hypertension (OHT) and to determine their clinical significance. Methods A total of 49 children with OHT were included in the OHT group. Forty-three age-and sex-matched healthy children were included in the control group. Heart rate and T wave and ST segment amplitude were measured in both groups. T wave amplitude and ST segment amplitude in supine ECG were compared with those in standing ECG within each group. The differences in supine vs standing T wave amplitude and ST segment amplitude were compared between the OHT and control groups. Results In the control group, T wave amplitude in leads aVR, V₁, and V₄-V₆ were significantly lower in standing ECG than in supine ECG (P < 0.05); ST segment amplitude in leads V₄ and V₅ were significantly higher in standing ECG than in supine ECG (P < 0.05). In the OHT group, T wave amplitude in leads Ⅱ, aVR, aVF, and V₄-V₆ were significantly lower in standing ECG than in supine ECG (P < 0.05); ST segment amplitude in lead Ⅱ was significantly higher in standing ECG than in supine ECG (P < 0.05). The differences in T wave amplitude in lead Ⅱ and V₆ between supine and standing ECG were significantly higher in the OHT group than in the control group (P < 0.05). Difference in T wave amplitude in lead V₆ between supine and standing ECG was a significant diagnostic marker for OHT (P < 0.05). This marker had 72.10% sensitivity and 57.10% specificity for the diagnosis of OHT at the optimal cut-off value of 0.105 mV. Conclusions Difference in T wave amplitude in lead V₆ between supine and standing ECG has certain diagnostic value for OHT.