Lehmann M H, Timothy K W, Frankovich D, Fromm B S, Keating M, Locati E H, Taggart R T, Towbin J A, Moss A J, Schwartz P J, Vincent G M
Arrhythmia Center/Sinai Hospital, Detroit, Michigan 48235, USA.
J Am Coll Cardiol. 1997 Jan;29(1):93-9. doi: 10.1016/s0735-1097(96)00454-8.
We sought to analyze age-gender differences in the rate-corrected QT (QTc) interval in the presence of a QT-prolonging gene.
Compared with men, women exhibit a longer QTc interval and an increased propensity toward torsade de pointes. In normal subjects, the QTc gender difference reflects QTc interval shortening in men during adolescence.
QTc intervals were analyzed according to age (< 16 or > or = 16 years) and gender in 460 genotyped blood relatives from families with long QT syndrome linked to chromosome 11p (KVLQT1; n = 199), 7q (HERG; n = 208) or 3p (SCN5A; n = 53).
The mean QTc interval in genotype-negative blood relatives (n = 240) was shortest in men, but similar among women, boys and girls. For genotype-positive blood relatives, men exhibited the shortest mean QTc interval in chromosome 7q- and 11p-linked blood relatives (n = 194), but not in the smaller 3p-linked group (n = 26). Among pooled 7q- and 11p-linked blood relatives, multiple regression analysis identified both genotype (p < 0.001) and age-gender group (men vs. women/children; p < 0.001) as significant predictors of the QTc interval; and heart rate (p < 0.001), genotype (p < 0.001) and age-gender group (p = 0.01) as significant predictors of the absolute QT interval. A shorter mean QT interval in men was most evident for heart rates < 60 beats/min.
In familial long QT syndrome linked to either chromosome 7q or 11p, men exhibit shorter mean QTc values than both women and children, for both genotype-positive and -negative blood relatives. Thus, adult gender differences in propensity toward torsade de pointes may reflect the relatively greater presence in men of a factor that blunts QT prolongation responses, especially at slow heart rates.
我们试图分析存在QT延长基因时校正心率的QT（QTc）间期的年龄-性别差异。
与男性相比，女性表现出更长的QTc间期以及更高的尖端扭转型室速倾向。在正常受试者中，QTc性别差异反映了男性在青春期QTc间期缩短。
对来自与11号染色体p臂（KVLQT1；n = 199）、7号染色体q臂（HERG；n = 208）或3号染色体p臂（SCN5A；n = 53）连锁的长QT综合征家族的460名基因分型血亲，根据年龄（<16岁或≥16岁）和性别分析QTc间期。
基因型阴性血亲（n = 240）的平均QTc间期在男性中最短，但在女性、男孩和女孩中相似。对于基因型阳性血亲，在与7号染色体q臂和11号染色体p臂连锁的血亲（n = 194）中，男性的平均QTc间期最短，但在较小的与3号染色体p臂连锁的组（n = 26）中并非如此。在合并的与7号染色体q臂和11号染色体p臂连锁的血亲中，多元回归分析确定基因型（p < 0.001）和年龄-性别组（男性与女性/儿童；p < 0.001）均为QTc间期的显著预测因素；心率（p < 0.001）、基因型（p < 0.001）和年龄-性别组（p = 0.01）为绝对QT间期的显著预测因素。男性较短的平均QT间期在心率<60次/分钟时最为明显。
在与7号染色体q臂或11号染色体p臂连锁的家族性长QT综合征中，对于基因型阳性和阴性血亲，男性的平均QTc值均短于女性和儿童。因此，成人尖端扭转型室速倾向的性别差异可能反映出男性中存在相对更多的一种可减弱QT延长反应的因素，尤其是在心率缓慢时。
