Vol 17, No 2 (2010)
Case Reports
Published online: 2010-03-29
Multifactorial QT interval prolongation
Cardiol J 2010;17(2):184-188.
Abstract
Acquired long QT interval has been widely reported to be a consequence of drug therapy and
electrolyte disturbances. We describe two cases of multifactorial acquired QT interval prolongation
and torsades de pointes. In the first case, the drugs venlafaxine, amiodarone and
domperidone may have contributed to QT interval prolongation in a patient with hypokalemia
and hypomagnesaemia. In the second case, QT interval prolongation occurred in a patient
taking quetiapine and citalopram, and whose use of hydrocholorothiazide and history of chronic
alcohol abuse likely contributed by rendering the patient hypokalemic. These cases highlight the
potential risks associated with polypharmacy and demonstrate that though torsades de pointes
is an uncommon arrhythmia, the combination of multiple factors known to prolong
QT interval may precipitate this life-threatening arrhythmia.
(Cardiol J 2010; 17, 2: 184-188)
(Cardiol J 2010; 17, 2: 184-188)
Keywords: acquired long QT interval