Figure 16 i

Top. P-wave synchronous ventricular pacing, with marker channels "P" indicating sensed P waves and "V' indicating paced ventricular complex. At 2 mV, there was appropriate P-wave sensing. Bottom. "A" indicates that the pacemaker is pacing the atrium. At the programmed sensitivity of 3 mV, there was undersensing of the P wave and there atrial pacing occurred. Hence, the sensed P-wave amplitude is between 2 and 3 mV.

Mitrani,R.D. and others,Cardiac Pacemakers,Hurst's The Heart,10th edition,Vol.1,pp.963-992