QT-interval monitoring is recommended by the American Heart Association (AHA) for several conditions: administration of medications that prolong the QT interval, overdose of medications that prolong...

QT-interval monitoring is recommended by the American Heart Association (AHA) for several conditions: administration of medications that prolong the QT interval, overdose of medications that prolong the QT interval, electrolyte disturbances (K⁺, Mg⁺), and bradycardia. It is not known what proportion of patients meet these criteria and would benefit from QT interval monitoring.