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Iohexol contrast medium induces QT prolongation in amiodarone patients
Matthias Goernig1, Thomas Kirmeier, Andreas Krack
1Friedrich-Schiller-University, Clinic of Internal Medicine III, Erlanger Allee 101, D-07740 Jena, Germany. Matthias.Goernig@med.uni-jena.de
Aims:
Amiodarone is widely used in ventricular tachyarrhythmias and atrial fibrillation, known to prolong QT-intervals. Concurrent administration of drugs prolonging QT- time can induce life-threatening ventricular tachyarrhythmia.
Methods:
QT-interval changes following use of Iohexol contrast-medium for coronarangiography were observed comparing 21 patients taking long-term amiodarone therapy with 21 controls not taking amiodarone or QT-prolonging drugs retrospectively.
Results:
Concurrent use of Iohexol and amiodarone was associated with significant prolongation of QTc-interval (433, 95%CI: 419-448 ms vs. 480, 95%CI: 422-483 ms, P < 0.001) the day after coronarangiograpgy. 6/21 patients showed severe prolonged QTc-interval of >500 ms.
Conclusion:
Caution is advised until more is known about pro-arrhythmic effects of Iohexol.
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