- 期刊
Cold Effect on QT Dispersion in Healthy Subjects
冰水效應對於正常人體心電圖上QT波段散亂度之影響
摘要
QT波段的散亂度(QT dispersion)，是指在12導程心電圖上最大與最小QT波段的差值。較大的QT散亂度已知是惡性心律不整或猝死症的獨立危險因子。在健康的個體上，交感神經強度的增加會加強QT散亂度，而冰冷刺激會增加交感神經活化也已眾所皆知。其於上述背影，我們總共收集了31位正常的成年人來評估冰水效應對於QT散亂度的影響。在每一位受試者中，我們分別取得其基準值、在4℃冰水浸潤三分鐘後、以及恢復期等共三次之心電圖。結果在冰水試驗下，QT散亂度(無論是否經心跳速率校正過後)均達到統計顯著之差異。進一步分析發現性別並不影響QT散亂度，但年齡則和QT散亂度之變異呈現相關性。若我們以37歲為區隔點，則發現在年齡較大的這一群人，其QT散亂度會有更明顯的差異性。我們的結論是，冰水效應會增加人體心電圖上QT散亂度，且此現象在年齡較大的人會更明顯。
關鍵字
無資料並列摘要
Thirty-one healthy subjects, aged 35±6 (21 to 48) years, were included in the study to evaluate the effect of ice water immersion on QT dispersion. There was no difference in the age between females (n = 11) and males (n = 20). Baseline, stress (at the end of ice water immersion, 4° C, for 3 minutes) and recovery 12lead electrocardiograms (ECGs) were recorded on each subject. During the test, a significant variability developed in both the QT dispersion (52 ±17, 68± 25 and 59 ± 21 ms; p = 0.015) and the corrected QT dispersion (56±17, 76±27 and 64±23 ms; p = 0.005), but not in the heart rate (74±11, 76±9, and 74±9 bpm, respectively; p = 0.447). There was no inter-sex difference in the baseline heart rate or QT dispersion, or in their response to ice water immersion. Age significantly correlated with the variation of QT dispersion to ice water immersion (r = 0.380, P = 0.035). With 37 years of age as a separation point, the variation of QT dispersion to ice water immersion was more obvious in the older group (28±22 vs. 10±19 ms, p = 0.023). In conclusion, cold may increase QT dispersion in healthy subjects, with a more obvious effect in the older ones.