Figure 18B shows the 12-lead ECG of the entrainment tracing of Figure 18A. The QRS morphology in all 12-lead ECGs during entrainment is identical to that of pacing in the absence of tachycardia as ...

This is absolutely important when dealing with athletes showing ventricular arrhythmias with left bundle branch block morphology or 12-lead ECG abnormalities such as right ventricular conduction delay ...