Influence of gender on drug-acquired long QT syndrome

Numerous drugs from diverse classes, such as antiarrhythmics, antihistamines, gastrokinetics, antipsychotics and antibiotics, share the potential to induce a prolongation of the QT interval on the electrocardiogram and torsade de pointes ventricular arrhythmias. The underlying mechanism of these side-effects is the blocking of voltage-gated potassium channels, particularly the rapid component I-Kr, of the delayed rectifier I-K. The risk of such drug-induced arrhythmias is far greater in women than in men. Clinical data as well as experimental studies show that, in comparison to men, the feminine gender is associated with a longer baseline QT interval, a greater response to drugs that block I-Kr and a greater propensity to drug-induced torsade de pointes. This is most likely the result of a specific regulation of channel expression by - and perhaps a direct non genomic effect of - sex steroids. (Eur Heart J Supplements 2001; 3 (Suppl K): K41-K47) (C) 2001 The European Society of Cardiology.