[Iatrogenic collapse; can this be prevented?].

In four patients, two men aged 65 and 35 years, and two women aged 87 and 83 years, who presented with collapse, administration of Q-T time prolonging drugs (sotalol, erythromycin, disopyramide) appeared to be the cause. These patients had so-called 'concealed long Q-T syndrome'. The proarrhythmogenic properties of antiarrhythmic and other drugs and of several clinical conditions such as cardiac diseases should be kept in mind when treating patients with antiarrhythmic substances.