Wavelet

Question 1

Is Wavelet applied at detection, redetect or both?

Answer 1

only at initial VT/VF detection or NID

Question 2

How does the Wavelet algorithm collect a template?

Answer 2

• collects and compares 6 R-wave samples to the programmed threshold value
• device confirms template by comparing R waves q10 secs to the template
• need 70 out of 100 R-wave matches to confirm the template
• if unable to confirm, will restart the collection process

Question 3

How often does the auto-collection feature of wavelet monitor/check R-waves to assess the quality of the stored template?

Answer 3

• assesses 100 R-waves q1000 secs

- if can’t get 70/100 R-wave matches, will recollect template

Question 4

How many beats does the Wavelet feature evaluate to determine a match percentage?

Answer 4

• looks back 8 beats once NID is met

Question 5

When will Wavelet withhold therapy?

Answer 5

• if at least 3 of the last 8 R-waves are a 70% or greater match with the store template

Question 6

What will be seen in the channel marker if Wavelet is withholding therapy?

Answer 6

WV

Question 7

What does a WV in the channel marker mean?

Answer 7

the Wavelet has withheld therapy

Question 8

What does HT in the channel marker mean?

Answer 8

indicates the High Rate Timeout timer expired, wavelet and PR-Logic stopped withholding therapy and detection

Question 9

Which EGM2 source does Wavelet use if RV Lead Noise is programmed ON?

Answer 9

CAN to RVcoil or RVcoil to SVC

Question 10

What would you do if the Wavelet signal amplitude is too small at collection?

Answer 10

• try a changing EGM2 to a different source that does not include the CAN
• try changing the EGM2 range

Question 11

What is the nominal setting for the PR-Logic/Wavelet High Rate Timeout?

Answer 11

45 seconds

Question 12

Where is Wavelet programmed on the device?

Answer 12

under V. Detection

Question 13

What is the fastest rate Wavelet will applied and what is the nominally setting?

Answer 13

SVT Limit at 260ms

Question 14

How does the device determine if Wavelet can be applied once the VT/VF NID is met?

Answer 14

• the device looks back at the last 12 V-V intervals and determines a median ventricular cycle length
• Wavelet is applied if the cycle length is greater than the SVT limit

Question 15

When collecting a Wavelet template, what is a possible solution if the Peak-Peak R-wave amplitudes are < 3mV on EGM2 and noise is seen?

Answer 15

change the EGM2 source

Question 16

When collecting a Wavelet template, what is a possible solution if the EGM (QRS) signal is clipped or is signal is within 1mV of the EGM2 range?

Answer 16

increase the EGM2 range

Question 17

When collecting a Wavelet template, what is a possible solution if the R-wave amplitude is too large at any range?

Answer 17

change the EGM source, then reassess beginning with a range of +/- 8 mV

Question 18

Can Wavelet collect a template if the patient is pacing 100% of the time?

Answer 18

No, sensing of intrinsic R-waves is required

Question 19

In single/dual chamber devices, is auto-collection for the Wavelet feature nominally on or off?

Answer 19

Nominally ON

Question 20

In CRT-D devices, is auto-collection for the Wavelet feature nominally on or off?

Answer 20

• Nominally OFF

- need to manually collect since the device will be pacing 100% of the time

Question 21

How long does it take for the device to confirm the Wavelet template after collection?

Answer 21

• at least 12 min

- longer if intrinsic rhythm has changed since collection

Question 22

How long is the Wavelet auto-collect suspended for when any of the following occurs: tachy episode, system test, EP study, Emergency operation?

Answer 22

suspended for 1 hr after termination of the episode or completion of the test/procedure

Question 23

For which patients do you have to manually collect a Wavelet template?

Answer 23

• pts with CRT-D devices

- pts who pace close to 100% of the time

Question 24

At follow/up, how do you confirm that the Wavelet template is consistent with the patients sinus rhythm?

Answer 24

Click on the “SHOW Match Scores” on the Wavelet test screen and collect a new template if scores are lest then an 80% match

Question 25

When will Wavelet evaluate the rhythm PR-Logic is also turned on?

Answer 25

- when PR-logic does not classify the rhythm as an SVT and withhold therapy - ventricular ≤ atrial rate