Thursday, September 04, 2008

Software Coming to Help Detect Medtronic Sprint Fidelis Lead Fractures

Sometime next week, we should be receiving software, called the "Lead Integrity Alert" that can be uploaded into existing Medtronic implantable cardiac defibrillators (ICDs) to help detect lead fractures from the recalled Sprint Fidelis (Model 6949) defibrillator leads. This software was approved by the FDA today and can be uploaded into the Medtronic's Marquis, Maximo, Virtuoso and Concerto ICD models non-invasively during a routine office visit. It is thought that such programming changes can reduce the number of patients who receive an inappropriate shock from a lead fracture before it is explanted by 38 to 40%. While not perfect, it might alert both the patient and physician earlier to a avoid unnecessary shocks should a lead fracture.

How the Software Works

There is a so-called Sensing Integrity Counter that usually trips an alert if there are greater than 300 counts of non-physiologic sensed intervals by the device. This software will lower this number to 30 or more to trigger an alert. Further, if there are an excessive number of very short "non-sustained ventricular tachycardia" sensed intervals, this also could trigger an alert. The software also allows an automatic adjustment of the "number of intervals to detect" to be automatically incremented to the next-higher detection ratio in hopes of averting a shock, while beeping six times a day (rather than once) to improve the chances a patient will notice the new alert state if tripped.

What to Do

Patients with the advisory leads will have the software automatically installed during their next routine office device check, but those who want it installed earlier should contact their doctor and inquire if the software could be installed earlier.

Realize this software only affects Medtronic ICDs. St. Jude and Boston Scientific devices are NOT affected.

-Wes

11 Sep 2008 Update: Medtronic's Info on the Lead Integrity Alert.

5 comments:

Anonymous said...

I thought medtronic said that it was less than a 1 percent chance of fracture.

Anonymous said...

This technology has been around since 2000. Its called Biotronik Home Monitoring. Works on both cell and landline. If any lead impedance changes MD will know within 2 minutes anywhere in the world via sms, fax, email and page. Only in Biotronik products, however...all of them! And its free! And it has HD IEGM for all events. The question is, why do so many EPs and MDs use inferior products like MDT and BSX?

DrWes said...

Anony 4:35PM:

Here's what Medtronic said.

Anony 5:28PM-
The issue here is the Sprint Fidelis lead advisory, not promoting one company over the other. To suggest that the software Biotronik offers is "free" is also disingenuous - I am aware of no company that charges for the software that communicates with their devices, rather the "cost" is included in device's purchase price.

sjsmargo said...

my husband went to have an upgrade, per order of his doctor about an advisory for his recalled lead, we are completely in the dark. We were told the lead was "capped off" during his surgery, yesterday the technician said his recalled lead was being used as a vector. Does anyone know anything about this??

Dr. Wes said...

sjsmargo-

Combination defibrillator leads like the Sprint Fidelis contain three leads in one: a pacing/sensing lead and two shocking coils. Some are advocating placing a regular pacing lead (instead of an entirely new combination defibrillator lead to replace the pace/sense portion of the combination defibrillator lead) to avoid sensing and pacing problems that might develop with the Sprint Fidelis lead. In these cases, the existing shocking coils in the Sprint Fidelis lead are still used to provide the high energy shock and this shock can be directed to the RV shocking coil (one so-called "vector") or to the SVC shocking coil (another shocking direction, or "vector") or both. It should be noted that the RV sensing problems from the pace-sense portion of the Sprint Fidelis lead occurred in majority of fractures reported, but some shocking coil leads also had fractures (see the original "Dear Doctor" letter of October, 2007).

Hope this helps explain things. I'd call Medtronic or your doctor if you have other questions.