User's Manual

25
Pacing Types – Modes
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Figure 3 and Table 1 summarize the timing intervals initiated by
sensing or pacing. The table distinguishes between pacing at the end
of the AV delay (V
P
) or pacing at the end of the AV safety delay (V
SP
)
and between sensing within the AV delay (V
S
) or sensing outside the AV
delay (VES).
Figure 3: Start of timing intervals in the DDD mode depending on the events
that occur
Event Timing Interval
A
p
A
s
V
p
V
sp
V
s
VES
Basic Interval (DDD)
• • •
Basic Interval (DDI)
• • • •
Atrial Refractory Period
• • •
Atrial Refractory Period -
Extension
•
Upper Tracking Rate Interval
• • • •
Ventricular Refractory Period
• • • •
Table 1: Timing intervals initiated by pace and sense events in DDD and DDI
modes (V
sp
= ventricular safety pacing)