Abbott
Algorithm summary
Single and dual chamber
•hysteresis
•Rest rate
Dual chamber only
•AICS
•VIP
Hysteresis
Rate hysteresis allows the clinician to program a base rate and a slightly lower hysteresis rate
•If the patient’s intrinsic rate is above the hysteresis rate, the device will be inhibited
•If the patient’s intrinsic rate falls below the hysteresis rate, the device will pace at the programmable base or intervention rate
Rate hysteresis encourages intrinsic activity, particularly in patients whose intrinsic rate is close to the programmed base rate
Hysteresis is enabled each time after an atrial event is sensed (dual chamber or AAI) or ventricular event is sensed (VVI)
Accessed from parameters; Rates; Hysteresis Settings;
•Hysteresis Rate (bpm):
•off, 30-130 (steps of 5), 130-150 (steps of 10)
•Search Interval (mins):
•off, 5, 10, 15, 30 (how often hysteresis search functions)
•Cycle Count (no. cycles):
•1-3 or 1-16 (depending on which device)
•Hysteresis Rate (bpm):
•off, 30-130 (steps of 5), 130-150 (steps of 10)
•Search Interval (mins):
•off, 5, 10, 15, 30 (how often hysteresis search functions)
•Cycle Count (no. cycles):
•1-3 or 1-16 (depending on which device)
Rest rate
allows the device to decrease its pacing rate automatically to a specified rate while the patient is asleep or in long periods of rest.
reduces the stimulation rate to a programmed rate below the Base Rate when the pulse generator detects that the patient has been inactive for more than 15 to 20 minutes.
provides a more comfortable & physiologic stimulation rate during sleep and can help prolong battery life.
determines inactivity through an algorithm that compares short-term sensor activity data to long-term data compiled over a period of 7 days.
prevents the device from inappropriately switching to the Rest Rate during short periods of inactivity.
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Accessed from parameters; Rates
Rest rate: Off; 30 – 130 in steps of 5; 140; 150
Auto intrinsic conduction search
Only in older devices (pre Accent)
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Accessed from parameters; Delays
•Settings: (ms):
•Off; + 10 ms to + 120 in steps of 10 (Nominal: Off) (under extended parameters)
•Search interval Settings: (min)
•Off; 5; 10; 15; 30 (Nominal: 5) (under basic parameters)
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Limited up to 90 bpm
Ventricular intrinsic preference
Under parameters; Delays;
•VIP on off
•VIP extension 50-150 in steps of 25, 150-200 in steps of 10
•Search Interval 30s 1, 3,5 10, 30 mins
•Search Cycles 1 2 3
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Limited up to 110bpm
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Available in newer devices (from Accent on)
Rest Rate
allows the device to decrease pacing rate automatically to a specified rate while the patient is asleep/in long periods of rest.
reduces the stimulation rate to a programmed rate below the Base Rate when the pulse generator detects that the patient has been inactive for more than 15 to 20 minutes.
can be used to provide a more comfortable & physiologic stimulation rate during sleep & can help prolong battery life.
rest rate determines inactivity through an algorithm that compares short-term sensor activity data to long-term data compiled over a period of seven days.
this prevents the device from inappropriately switching to the Rest Rate during short periods of inactivity.
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Under parameters; rates;
•Rest rate Off, 30-130 in steps of 5, 140, 150