Acquired long QT syndrome and drug-induced cardiac arrhythmias

A range of cardiac and non-cardiac medications can prolong the duration of ventricular repolarisation, which is reflected by an increase in the QT interval on the surface ECG. This can result in life threatening arrhythmias, particularly in patients with an inherited or acquired defect of cardiac ion channel function. Non-cardiac drugs that are known to cause QT prolongation are relatively contraindicated in patients with structural heart disease and absolutely contraindicated in patients with a congenital long-QT syndrome. A high level of vigilance is required to reduce the incidence of drug-induced ventricular arrhythmias. (author abstract)