Polymorphous ventricular tachycardia due to alpha-blockade.

We report a case of polymorphous ventricular tachycardia caused by treatment with the post-synaptic alpha-blocking agent indoramin. This has not been reported with indoramin previously, nor to our knowledge with any other alpha-blocker. This pro-arrhythmic effect appears to be related to its class 3 anti-arrhythmic properties (QT interval prolongation) which is dose dependent, occurring only at large doses.