Spiked helmet sign after percutaneous left stellate ganglion ablation in a patient with long QT syndrome.

"Spiked helmet" is a type of ST elevation, which is generally observed in critically ill patients and associated with very poor prognosis. Here we present a case of previously undiagnosed long QT syndrome admitted with polymorphic ventricular tachycardia (PMVT) unresponsive to pharmacological treatment and developed "spiked helmet" sign after left percutaneous stellate ganglion ablation.