VVI pacing presents with a regular wide QRS preceded by a pacing artifact and an independent atrial activity that is AV dissociation. VVI pacing indicates pacing in the ventricle when needed, but sensing and inhibition by intrinsic ventricular activity. The independent atrial activity is not sensed, as there is no atrial lead with pacemaker. Pacemaker spikes can frequently be very small and may not necessarily be visible in all twelve leads. With a single ventricular chamber transvenous pacemaker lead, the 12-lead ECG QRS will show a LBBB configuration with a superior axis, reflecting right ventricular apical pacing. The following animation illustrates what we have just described.