Implantable cardioverter defibrillator

• Most of this 12-lead recording is polymorphic ventricular tachycardia but, in the rhythm strip, the large deflection (arrowed) is the defibrillator discharging.
• Following the defibrillation a dual chamber pacemaker can be seen.

OK so I cheated a little with this one as the odds of catching this on a 12-lead ECG recording are very slim indeed. This is a reconstructed 12-lead recording from an electrophysiology study testing the device after placement.