Medicines Management & Pharmacy Services, Leeds Teaching Hospitals NHS Trust, Leeds, UK
Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds, UK.
Postgrad Med J. 2021 Jul;97(1149):452-458. doi: 10.1136/postgradmedj-2020-138661. Epub 2020 Oct 29.
Many drug therapies are associated with prolongation of the QT interval. This may increase the risk of Torsades de Pointes (TdP), a potentially life-threatening cardiac arrhythmia. As the QT interval varies with a change in heart rate, various formulae can adjust for this, producing a 'corrected QT' (QTc) value. Normal QTc intervals are typically <450 ms for men and <460 ms for women. For every 10 ms increase, there is a ~5% increase in the risk of arrhythmic events. When prescribing drugs associated with QT prolongation, three key factors should be considered: patient-related risk factors (eg, female sex, age >65 years, uncorrected electrolyte disturbances); the potential risk and degree of QT prolongation associated with the proposed drug; and co-prescribed medicines that could increase the risk of QT prolongation. To support clinicians, who are likely to prescribe such medicines in their daily practice, we developed a simple algorithm to help guide clinical management in patients who are at risk of QT prolongation/TdP, those exposed to QT-prolonging medication or have QT prolongation.
许多药物治疗与 QT 间期延长有关。这可能会增加尖端扭转型室性心动过速（TdP）的风险，这是一种潜在的危及生命的心律失常。由于 QT 间期随心率变化而变化，因此可以使用各种公式进行调整，得出“校正 QT”（QTc）值。正常的 QTc 间期通常男性<450ms，女性<460ms。QTc 间期每增加 10ms，心律失常事件的风险就会增加约 5%。在开具与 QT 间期延长相关的药物时，应考虑三个关键因素：患者相关的危险因素（例如，女性、年龄>65 岁、未纠正的电解质紊乱）；拟用药物与 QT 延长相关的潜在风险和程度；以及可能增加 QT 延长风险的同时使用的药物。为了支持可能在日常实践中开具此类药物的临床医生，我们开发了一个简单的算法，以帮助指导有 QT 延长/尖端扭转型室性心动过速风险、暴露于延长 QT 间期药物或有 QT 间期延长的患者的临床管理。
