The changes of amplitude of T wave and ST segment between the supine and orthostatic electrocardio-gram in children and adolescents with postural tachycardia syndrome / 中国小儿急救医学

ABSTRACT

Objective To investigate the changes of amplitude of T wave and ST segment between the supine and orthostatic electrocardiogram in children and adolescents with postural tachycardia syndrome (POTS). Methods A total of 74 children and adolescents diagnosed as POTS by head-up tilt test (HUTT),who complained of unexplained dizziness,headache,syncope or other symptoms,were chosen as POTS group. A total of 64 children and adolescents who did the health check in our child health clinic were selected as control group by age and sex in the same period. All the cases in this study came from the syncope specialized clinic or inpatient department of the Second Xiangya Hospital,Central South University,from August 2013 to January 2016. The heart rate and the 12-lead T-wave and ST-segment amplitude of the supine and orthostatic electrocardiogram were measured by software and manual intervention. Results (1) Com-pared with supine electrocardiogram,the heart rate of orthostatic electrocardiogram of POTS group increased [(105. 2 ± 16. 3) times/ min vs. (83. 8 ± 18. 0) times/ min,t = - 7. 598,P < 0. 01],the T-wave amplitude decreased in lead Ⅰ[(0. 28 ± 0. 14) mV vs. (0. 33 ± 0. 11) mV,t = 2. 598,P < 0. 05],Ⅱ[(0. 28 ± 0. 12) mV vs. (0. 39 ± 0. 13) mV,t = 5. 340,P < 0. 01],Ⅲ[(0. 00 ± 0. 19) mV vs. (0. 07 ± 0. 11) mV,t = 3. 041, P < 0. 01],aVF[(0. 14 ± 0. 13) mV vs. (0. 23 ± 0. 11) mV,t = 4. 505,P < 0. 01],V4 [(0. 33 ± 0. 21) mV vs. (0. 51 ± 0. 23) mV,t = 4. 938,P < 0. 01],V5 [(0. 37 ± 0. 10) mV vs. (0. 50 ± 0. 15) mV,t = 7. 764,P <0. 01] and V6 [(0. 25 ± 0. 10) mV vs. (0. 37 ± 0. 10) mV,t = 7. 538,P < 0. 01],the T-wave amplitude in-creased in lead aVR[( - 0. 27 ± 0. 11) mV vs. ( - 0. 36 ± 0. 10) mV,t = - 5. 023,P < 0. 01],and the ST-segment amplitude increased in lead V 5 [(0. 07 ± 0. 04) mV vs. (0. 06 ± 0. 04) mV,t = - 2. 309,P < 0. 05]. (2) Compared with control group,the difference of heart rate of POTS group increased [( - 21. 4 ± 14. 0) times/ min vs. ( - 10. 7 ± 11. 4)times/ min,t = 4. 875,P < 0. 01],and the difference of T-wave amplitude in-creased in lead Ⅰ[(0. 05 ± 0. 10) mV vs. ( - 0. 01 ± 0. 15) mV,t = - 3. 161,P < 0. 01],Ⅱ[(0. 11 ± 0. 12) mV vs. (0. 07 ± 0. 12) mV,t = - 2. 243,P < 0. 05],V4 [(0. 18 ± 0. 18) mV vs. (0. 07 ± 0. 20) mV,t =- 3. 282,P < 0. 01],V5 [(0. 18 ± 0. 11) mV vs. (0. 14 ± 0. 13) mV,t = - 2. 013,P < 0. 05] and V6 [(0. 13 ± 0. 08) mV vs. (0. 08 ± 0. 10) mV,t = - 3. 364,P < 0. 01],and the difference of T-wave amplitude in-creased significant in lead aVR[( - 0. 09 ± 0. 08) mV vs. ( - 0. 03 ± 0. 08) mV,t = 4. 109,P < 0. 01]. (3) Logistic regression analysis:the difference of heart rate and T-wave amplitude in lead V5 and V6 on supine and orthostatic electrocardiogram was statistically valuable for the diagnosis of POTS (P < 0. 05). (4) Diag-nostic test evaluationwhen the difference of heart rate ≥15 times/ min,of T-wave amplitude in lead V5 and lead V 6≥ 0. 10 mV separately,on supine and orthostatic electrocardiogram at the same time,the sensitivity of the diagnosis of POTS was 37. 8％ and the specificity was 81. 3％ . (5)The follow-up of children and adoles-cents with POTS showed no significant difference of T-wave amplitude and ST-segment amplitude on ortho-static and supine ECG comparing to the initial diagnosis,regardless of the type of HUTT reaction remained or turned negative (P >0. 05). Conclusion The difference of heart rate and of T-wave amplitude in lead V5 and V6 are valuable for the diagnosis of POTS in children and adolescents.