Specifications

7 x 9 inches (178 mm x 229 mm)
Medtronic Confidential
Refer to the “Reference man.” category in doc#163256 for Printing
Instructions.
196407001 Rev A
Non-Competitive Atrial Pacing
Overview
Non-Competitive Atrial Pacing (NCAP) is intended to prevent triggering of
atrial tachycardias by an atrial pacing stimulus that falls within the atrium’s
relative refractory period. This feature may be programmed ON/OFF in the
DDDR mode only.
How NCAP Affects Atrial Timing
When NCAP is programmed ON, a refractory sensed atrial event falling in
the PVARP starts a 300 ms NCAP period, during which no atrial pacing
may occur:
■
If a sensor-driven or lower rate pacing stimulus is scheduled to occur
during the NCAP period, the VA interval is extended until the NCAP
period expires.
■
If no pacing stimulus is scheduled to occur during the NCAP period,
timing is unaffected; pacing occurs at the end of the VA interval unless
inhibited.
■
An atrial refractory sensed event occurring during the NCAP period
starts a new NCAP period.
The Atrium’s Relative Refractory Period
Special Therapy Options 14-5
Pace Atrium safely,
no capture
Pace Atrium
safely, capture
Relative refractory
period, atrial pace
may induce atrial tachy
9879EN-14_9501043EN/CTC.qxd 5/10/99 11:31 Page 14-5