Yang H, Elko P, Fromm B S, Baga J J, Pires L A, Schuger C D, Steinman R T, Lehmann M H
Arrhythmia Center, Sinai Hospital Detroit, Michigan 48235, USA.
J Electrocardiol. 1997 Oct;30(4):267-76. doi: 10.1016/s0022-0736(97)80038-6.
To investigate possible sex differences in the dynamics of T wave generation, the maximum instantaneous slope of the ascending and descending limbs of the T wave (max dV/dt and min dV/dt, respectively), were calculated. These rate of repolarization parameters, as well as more traditional repolarization duration parameters (QT, JT, Q to T wave peak [QTm] and J to T wave peak [JTm]), were measured by computer using digitized electrocardiograms (ECGs) from the V5 lead in 562 normal subjects (443 men and 119 women; mean age 37 years), whose heart rates (HRs) were confined to one of three narrow ranges, namely 60 +/- 1, 70 +/- 1, or 80 +/- 1 beats/min. In both men and women, for each HR range absolute values of min dV/dt exceeded those of max dV/dt (P < .0001). However, absolute values of both max dV/dt and min dV/dt were consistently greater in men than in women for each HR range (P < .0001 at HR 60 +/- 1; P < .02 at HR 70 +/- 1, or 80 +/- 1). By using correlation analysis, max dV/dt and min dV/dt were shown to be independent of the repolarization duration variables (r < .30). Thus, whereas in both men and women the descending limb of the T wave is steeper than the ascending limb, the maximum slope of each limb of the T wave is steeper in men than in women. These findings add to a growing body of data indicating fundamental sex differences in the physiology of cardiac repolarization and propensity to torsade de pointes.
为了研究T波产生动力学中可能存在的性别差异，计算了T波上升支和下降支的最大瞬时斜率（分别为最大dV/dt和最小dV/dt）。这些复极速率参数以及更传统的复极持续时间参数（QT、JT、Q至T波峰值[QTm]和J至T波峰值[JTm]），通过计算机使用来自562名正常受试者（443名男性和119名女性；平均年龄37岁）V5导联的数字化心电图（ECG）进行测量，这些受试者的心率（HR）被限制在三个狭窄范围之一，即60±1、70±1或80±1次/分钟。在男性和女性中，对于每个心率范围，最小dV/dt的绝对值均超过最大dV/dt的绝对值（P<.0001）。然而，在每个心率范围内，男性的最大dV/dt和最小dV/dt的绝对值始终大于女性（心率60±1时P<.0001；心率70±1或80±1时P<.02）。通过相关性分析，最大dV/dt和最小dV/dt被证明与复极持续时间变量无关（r<.30）。因此，虽然在男性和女性中T波的下降支都比上升支更陡峭，但男性T波每个分支的最大斜率比女性更陡峭。这些发现进一步增加了越来越多的数据，表明心脏复极生理学和尖端扭转型室速易感性存在基本的性别差异。
