Yamashita T, Inoue H, Usui M, Kuo T, Saihara S, Nozaki A, Momomura S, Serizawa T, Iizuka M, Sugimoto T
Second Department of Internal Medicine, Tokyo University Hospital, Japan.
Am Heart J. 1991 Jun;121(6 Pt 1):1634-9. doi: 10.1016/0002-8703(91)90006-4.
Percutaneous balloon valvuloplasty for pulmonary or aortic stenosis results in QT prolongation, a finding supporting the presence of contraction-excitation feedback in man. Though afterload reduction alters the QT interval, the effect of changes in preload on ventricular repolarization is yet unknown. To test whether diastolic stretch modified ventricular repolarization, the change in the QT interval was determined in 15 patients who underwent percutaneous transluminal mitral commissurotomy (PTMC) for mitral stenosis. After successful PTMC, the QT interval was prolonged in five, shortened in two, and was unchanged in eight patients, but the mean QT interval in 15 patients did not change (406 +/- 31 msec versus 412 +/- 40 msec, p = NS). However, linear regression analysis revealed a strong correlation between changes in the QT interval and those in systemic vascular resistance (r = -0.83, p less than 0.01). These data indicated that changes in the QT interval after PTMC were small compared with those seen with valvuloplasty for pulmonary or aortic stenosis, and were dependent on afterload but not on preload.
经皮肺动脉或主动脉瓣球囊成形术可导致QT间期延长，这一发现支持人体存在收缩-兴奋反馈。尽管后负荷降低会改变QT间期，但前负荷变化对心室复极的影响尚不清楚。为了测试舒张期牵张是否改变心室复极，我们测定了15例因二尖瓣狭窄接受经皮二尖瓣交界分离术（PTMC）患者的QT间期变化。PTMC成功后，5例患者QT间期延长，2例缩短，8例无变化，但15例患者的平均QT间期未改变（406±31毫秒对412±40毫秒，p=无显著性差异）。然而，线性回归分析显示QT间期变化与体循环血管阻力变化之间存在强相关性（r=-0.83，p<0.01）。这些数据表明，与肺动脉或主动脉瓣成形术相比，PTMC后QT间期的变化较小，且依赖于后负荷而非前负荷。
