Is Defibrillation Testing Still Necessary At the Time of ICD Implantation? February 5, 2010
Posted by Andrea M. Russo, MD, FACC, FHRS in Scientific Sessions.Tags: ICD, Ventricular fibrillation, VF
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With modern Implantable Cardioverter Defibrillator (ICD) technology, should we really still be doing defibrillation testing at the time of initial ICD implantation?
There is clearly a small, but real mortality rate related to the induction of ventricular fibrillation (VF), not to mention other potential complications such as stroke related to defibrillation testing. In addition, this testing adds to the cost of the procedure, which is an important concern.
The need for implantation testing has been questioned because system revision related to a high defibrillation threshold is rarely necessary with modern devices that have biphasic waveforms and active cans. However, would you ever consider buying a car if that vehicle had never undergone a “test run?” Don’t we want to make sure that a potentially life-saving device detects and treats VF appropriately in a controlled setting, before patients need therapy in “real life?” Such testing takes only seconds to minutes to perform, and the potential benefits might outweigh the minuscule risk of testing.
Tell me what you think in the comments section and hear more about the debate on this topic during a dedicated “Ideas on Trial” session at the Heart Rhythm Society’s Scientific Sessions: “Defibrillation Tests Are Required in All Patients Receiving an Implantable Cardioverter Defibrillator,” Thursday, May 13, 11:30 a.m. – 12:15 p.m.
Heart Rhythm Society
Laurie Racenet, RN, MSN, ANP
Michael Giudici, MD, FACC, FACP, FHRS
Heather M. Ross, DNP, ANP-BC, CCDS, CEPS, FHRS
Anne Dubin, MD, FHRS
John D. Day, MD, FHRS
Andrea M. Russo, MD, FACC, FHRS
Joshua M. Cooper, MD, FACC
Amit J. Shanker, MD, FHRS, FACC
Bruce Stambler, MD
David Wiggins, RN, BS BME, CEPS
Fred M. Kusumoto, MD, FHRS
Leonard Ganz, MD, FHRS
christinechiuman
Craig Delaughter, MD, PhD
Ariana Del Negro, Heart Rhythm 2010 Quality
Peng-Sheng Chen, MD, FHRS
MSKremers MD,FHRS
Ann C. Garlitski, MD, FACC, FHRS
Alan Cheng, MD, FHRS
Ulrika Birgersdotter-Green, MD
Christopher Clyne, MD, FHRS
Kathleen Blake, MD, MPH, FHRS
David Scher, MD, FHRS
Sanjay Deshpande, MD, FHRS
You do not test only DFT during DFT testing. You test sensing of VF which some times can be a problem. I had at least two cases when despite the appropriate sensing of R wave the device had failed sensing VF at all sensitivity levels. DFT does not matter when VF is undersensed.
The risk of stroke with DFT testing has to be close to 0 if AF pts are implanted with a therapeutic INR. AF can be reinduced if the INR is subtherapeutic or DFT testing can be withheld in these patients.
I agree that undersensing, typically of a slow polymorphic rhythm in a patient on amiodarone for example is something you can see and need to know about. Inadequate DFT’s are not that rare or there wouldn’t be a sub Q lead or the ability in some devices to optimize the waveform. These issues are far more likely than a significant complication from testing in my experience.
DFT testing is needed at implant aand also at regular intervals, if there were no DFT shocks were received overr period.
At implant every year I find a couple of patients with high DFTs needing extra hardware.
Recently, in two patients the DFT was high. They did not receive any ICD shocks for VT/VF episodes in the preceeding two years. All other parameters were normal. Both patients have had highout devices.
Until guide lines for chronic DFT testing is establishes the testing should be done once every one to two years if there were no ICD shockd in the preceeding year of two.