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Figure 3 Dissociation of the Isolated Segment From the Atrium

After complete atrioventricular block was confirmed, pacing from the isolated atrial segment at a cycle length of 700 ms (86 beats/min) activated both ventricles with a fixed interval between the pacing spike and the ventricular activation. The isolated atrial segment and ventricles were dissociated with both the atria, which were in sinus rhythm at 97 beats/min. The recording format is the same as in Figure 2. HV = interval between His potential and ventricular signal; SV = interval between pacing spike and ventricular signal; other abbreviations as in Figure 2.