Accelerated Idioventricular Rhythm

A ventricular escape rhythm at a rate faster than the normal idioventricular rate (20–40 bpm) but slower than VTach. Rate 50–110 bpm (typically 70–100). Classic reperfusion rhythm after STEMI thrombolysis or PCI — the 'reperfusion arrhythmia'.

• Regular wide-complex rhythm (QRS >120 ms) at 50–110 bpm.
• No P waves or AV dissociation.
• Fusion beats may occur at onset/termination when sinus and ventricular rhythms compete.
• QRS morphology identical to PVC.

Usually benign and self-limiting. Does not require treatment unless hemodynamically unstable. Considered a favorable sign during acute MI — indicates restored coronary flow. Distinguish from VTach by slower rate.