老年人运动试验结果与Q-T离散度变化的关系

Relationship between results in bicycle exercise test and changes in Q-T dispersion in aged

为探讨Q-T离散度(Q-T_d)变化的机制,观察39例老年人踏车运动试验前后心肌复极Q-T_d变化。结果显示:运动试验阴性组运动前Q-T_d、Q-T_(cd)及Q-T_d/R-R分别为38.6±9.9ms、43.6±12.1ms及4.95±1.55％,阳性组运动前为40.6±14.8ms、45.9±17.3ms及5.29±2.01％,两组均无显著性差异(P>0.05)。阴性组运动后上述3值为26.4±8.5ms,35.4±10.1ms及4.77±1.24％,其中Q-T_d及Q-T_(cd)显著缩短(P<0.001及0.05);阳性组为35.9±9.4ms、48.9±12.9ms及6.59±1.86％,其中Q-T_d/R-R显著延长(P<0.001),两组有显著性差异(P<0.01—0.001)。提示运动缩短健康老年人心肌复极离散度,但运动诱发的心肌缺血却使之延长。

In order to investigate exact mechanism of changes in Q-T dispersion, 39 aged with chest discomfort or pain received a bicycle exercise test. Results showed that before exercise, their Q-Td, Q-Tcd and Q-Td/R-R compared between positive and negative groups ( P > 0. 05) were within normal range. After exercises their Q-Td and Q-Tcd decreased ( P < 0. 001 ,P <0. 05), respectively, in negative group, and Q-Td/R-R increased ( P <0. 001) in positive group. Q-Td, Q-Tcd and Q-Td/R-R were significant higher in positive group than those in negative group( P<0. 01-0. 001 ) after exercises. It suggests that exercise does not increase but reduce Q-T dispersion in healthy aged, while myocar-dial ischemia induced by exercises might increase Q-T dispersion of myocardium in aged.