Effect of intravenous propranolol on QT interval. A new method of assessment.
Effect of intravenous propranolol on QT interval. A new method of assessment.
复制标题
静脉注射普萘洛尔对 QT 间期的影响。
DOI：
10.1136/hrt.43.1.1
复制
发表时间：
1980
影响因子：
--
通讯作者：
R. Spurrell
中科院分区：
文献类型：
--
作者：
J. Milne;A. Camm;D. Ward;R. Spurrell
本文观察了16例患者以100、130和150次/分钟的频率起搏时QT间期和QT间期的变化。在所有患者中，随着心房起搏频率的增加，测量的QT缩短，但当校正心率时，QT间期延长。在研究的16名患者中，静脉注射心得安的15名患者出现了心动过缓和QT间期延长。使用Bazett公式对QT间期进行心率校正后，13例患者的QT间期缩短，1例患者的QT间期不变，2例患者的QT间期延长。然而，当以相同的心房起搏频率测量QT间期时，研究的15名患者中有10名QT延长，5名患者没有变化。无一例QT间期缩短。这些结果表明，首先，Bazett公式不适合校正心房起搏引起的QT间期改变；其次，静脉注射心得安通常会使QT间期缩短，但当用相同的心房起搏频率直接评估其效果时，QT间期通常延长，或可能保持不变，但从不缩短。建议对药物引起的QT间期改变的正式评估应以相同的心房起搏频率进行。
Changes in the QT and QTc intervals were studied in 16 patients by atrial pacing at rates of 100, 130, and 150 beats/minute. In all patients the measured QT shortened when the atrial paced rate was increased, but when corrected for heart rate the QTc lengthened. Intravenously administered propranolol produced a bradycardia and a lengthening of the QT interval in 15 of the 16 patients studied. When the QT interval was corrected for heart rate using Bazett's formula the QTc was shortened in 13 patients, unchanged in one, and lengthened in two. However, when the QT interval was measured at identical atrial paced rates the QT of the 15 patients studied was lengthened in 10 and unchanged in five. In none was the QT interval shortened. These results show firstly that Bazett's formula is unsuitable for correction of QT interval changes induced by atrial pacing, and secondly that, though intravenously administered propranolol usally produces a shortening of the QTc, when its effect is assessed directly by using an identical atrial paced rate the QT interval usually lengthens, or may remain unchanged, but never shortens. It is suggested that the formal assessment of drug induced QT interval changes should be made at identical atrial paced rates.