Auto-PVARP

Question 1

What is the purpose of the Auto-PVARP feature?

Answer 1

• to prevent 2:1 block by shortening PVARP with fast rates to track sinus P-waves up to the UTR (long PVARP may not track all P-waves)
• to prevent tracking of retrograde P-waves or PAC’s by lengthening PVARP with slower rates (P-waves fall into refractory = AR)

Question 2

How does Auto-PVARP prevent 2:1 block from occurring?

Answer 2

• shortens PVARP and SAV if needed at fast rates to keep the 2:1 block rate/TARP 30 bpms above the mean atrial rate (MAR)

Question 3

What timing intervals make up the Total Atrial Refractory Period (TARP)

Answer 3

SAV + PVARP

Question 4

Auto-PVARP maintains what 2:1 block/TARP rate to prevent 2:1 block from occurring?

Answer 4

Mean Atrial Rate (MAR) + 30bpm
-> PVARP is auto adjusted to keep TARP (2:1 block rate) 30 bpm above the MAR

Question 5

What is the safety margin used when programming the Total Atrial Refractory Period or 2:1 block point?

Answer 5

Program TARP (SAV + PVARP) to be 30 bpm above the UTR to allow for a Weinchebach window
-> UTR = 130bpm/460ms
-> TARP should be programmed to 160bpm/375ms
-> if SAV=150 then PVARP = 225ms

Question 6

What rate does Auto-PVARP use when adjusting PVARP?

Answer 6

Mean Atrial Rate (MAR) updated every 4 beats

Question 7

Why is Auto-PVARP important for patients with paroxysmal or intermittent Atrial Tachyarrhythmias?

Answer 7

• feature limits high ventricular tracking rates during the onset of the atrial tachyarrhythmia until the device mode switches to non-tracking mode (DDI or DDIR)