Ventricular pacemaker

A 72 year old man with a permanent pacemaker.

• pacing spikes (best seen here in V4 - V6) will be seen - they may be subtle
• the paced QRS complexes are abnormally wide

In this example the pacemaker starts when there is a long R - R interval following a blocked atrial premature beat (arrowed in figure below). Sinus rhythm takes over again later in the rhythm strip.