ICD System High Voltage Component Failure (Presented to FDA)
- 1. ICD Lead High-Voltage Component Failure How to Identify ICD Leads and Systems That Will Not Deliver Shocks Edward J. Schloss MD FACC FHRS Presented to FDA October 14, 2014
- 2. Disclosures • Medtronic: Consultant, Speaker • Boston Scientific: Consultant, Speaker
- 3. Components of ICD System SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament ICD Can
- 4. Low Voltage Function - Sensing SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament ICD Can
- 5. Low Voltage Function - Pacing SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament ICD Can
- 6. High Voltage Function SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament ICD Can
- 7. High Voltage Failure is Tough to Detect • Impedance is only measured parameter – No sensing/noise alerts, no pacing threshold • Testing amplitude is order of magnitude less than working stress on lead • Failure may be asymptomatic and go undetected for years • First presentation may be sudden cardiac arrest or death – High voltage failure is “quiet” – May go undiagnosed if no postmortem interrogation
- 8. How does HV Failure Present? • Silent failure, picked up with remote notification
- 9. How does HV Failure Present? • Silent failure, picked up with remote notification • Silent failure, picked up in office
- 10. How does HV Failure Present? • Silent failure, picked up with remote notification • Silent failure, picked up in office • Silent failure, seen w/hospital shock testing “annual DFT testing, once a common clinical practice is performed infrequently today” JACC Aug 2008
- 11. How does HV Failure Present? • Silent failure, picked up with remote notification • Silent failure, picked up in office • Silent failure, picked up w/hospital HV testing • Clinical Shock with manifest failure – Inappropriate
- 12. How does HV Failure Present? • Silent failure, picked up with remote notification • Silent failure, picked up in office • Silent failure, picked up w/hospital HV testing • Clinical Shock with manifest failure – Inappropriate – Appropriate Lee Oukrup with portrait of son Joshua www.nbcnews.com
- 13. How Do We Detect HV Component Failure? • What can fail? – Pulse Generator
- 14. How Do We Detect HV Component Failure? • What can fail? – Pulse Generator – Generator/Lead Interface – i.e. header
- 15. How Do We Detect HV Component Failure? • What can fail? – Pulse Generator – Generator/Lead Interface – i.e. header – Lead • Weakest Link in the Chain • Types of Failures – Conductor – Insulator
- 16. Shock Lead Impedance Testing • Pulse delivered automatically every 21 hours – Older generation devices 15 mA for 60 μsec – Newer generation devices 80 μA for 156 μsec (10 Ω higher) • Red Alert in Latitude if >125 Ω or <20 Ω (programmable) • Measures each TRIAD vector separately and combines to single value
- 17. Shock Lead Impedance Testing • Pulse delivered once a week – 4V for 20 msec, Coil to can • Normal defined as <400 Ω • Abnormal will show up as alert on interrogation • With shock, normal is <200 Ω
- 18. Shock Lead Impedance Testing • Pulse delivered daily (up to 4 attempts) – 400 mV for 90 msec • Two vectors reported – HV Impedance = RV coil to SVC coil+Can – SVC Impedance = RV coil to SVC coil • Alarm for Impedance < 20Ω, > 200Ω (programmable) • Triggers clinician and patient alert (not LIA)
- 19. Shock Lead Impedance Testing • Atlas/Epic have no daily measurements • Physician generated HVLI test (12v) • Later Generations HV pulse delivered daily – All vectors (RV and SVC to can) • Alert impedances are programmable
- 20. Evidence Base for Shock Lead Integrity Testing Canine Model Looked intact and disrupted (high Ω) lead configurations Pacing pulses and shocks measured over wide range of impedances from normal to high Close correlation suggests low voltage measurements predict high impedance failure Did not test for low impedance failure
- 21. Evidence Base for Shock Lead Integrity Testing Validation of newly developed HV testing technique 29 pts with Guidant PRIZM ICDs at implant All pts got 0.4 μ J pulse, 1.1 J, and 16-45 J shocks Impedances measured for all pulse strenths Low energy pulses correlated with high energy shocks Only new functional leads were tested
- 22. Evidence Base for Shock Lead Integrity Testing "Partial insulation defects may not be identified by low-energy pulses that deliver insufficient current to activate the shorted high-output protection feature." Swerdlow/Friedman Pacing Clin Electrophysiol. 2006;29(1):70- 96.
- 23. Response to Failed Shock Conductor Failure – High impedance – Cable fracture, Set screw issue • Fidelis – Current delivery attenuated to affected limb of circuit • RV coil likely ineffective shock • SVC coil likely effective shock unless high DFT – Device will be unharmed and report out a high impedance alert
- 24. Response to Failed Shock Insulator Failure – Low impedance – Abrasion: can/coil , coil/coil, Header short • Riata, PRIZM 2 DR – HV Current pulse generator as a short • Older devices: current shunted from heart , electrical overstress may damage PG • Newer devices: current shunted, PG protected. – If PG is still intact, low Ω alert issued. – St. Jude Dynamic Tx • Reconfigures shock to remove SVC coil or can from circuit if breach detected.
- 25. HV Component Failure by Lead Model • Evolution to cable design associated with improved lead performance www.bostonscientific.com Medtronic Transvene Ellenbogen et al. JACC Jan 1, 2003
- 26. Medtronic Fidelis High voltage performance not broken out in PPR data
- 27. Medtronic Fidelis • HV Failures: 5% of overall failures in series Circulation. 2011;123:358-363
- 28. Medtronic Fidelis • HV Failures: 5% of overall failures in series • HV Failures: 6.1% of overall failures in RPA
- 29. Medtronic Fidelis • HV Failures: 5% of overall failures in series • HV Failures: 6.1% of overall failures in RPA • Conductor fracture (abrupt >100 Ω) in all RPA
- 30. Medtronic Fidelis • HV Failures: 5% of overall failures in series • HV Failures: 6.1% of overall failures in RPA • Conductor fracture (abrupt >100 Ω) in all RPA • Failure of pace-sense electrode predicts failure of high voltage conductors Medtronic Field Communication April 2011 Medtronic Field Communication April 2011
- 31. Medtronic Fidelis Conductor fracture, New pace/sense lead 5076 SVC cable fracture RV cable fracture
- 32. St. Jude Riata/Riata ST WSJ.com Cardiobrief.org
- 33. Riata High Voltage Shock Delivery SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament ICD Can
- 34. Riata HV Insulation Shorts SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament z1 2 ICD Can 3 3 RV HV cable/coil shorts to SVC cable/coil or can
- 35. Riata HV Insulation Shorts SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 1) RV HV cable to can z1 ICD Can Programming the can out of the system may mitigate (if dual coil lead)
- 36. Riata HV Insulation Shorts SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 2 1) RV HV cable to can 2) RV HV cable to SVC cable or coil ICD Can Programming SVC Coil out of system may mitigate failure
- 37. Riata HV Insulation Shorts SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 1) RV HV cable to can 2) RV HV cable to SVC cable or coil 3) RV Ring P/S cable to RV HV cable and RV ring to can ICD Can 3 3 Other variations of #3 exist with alternative return circuit
- 38. Detection of Riata/ST Failures • Earlier generation ICDs (Atlas/Epic) do not have automatic HV testing High voltage testing with Atlas/Epic must be performed manually
- 39. Detection of Riata/ST Failures • Earlier generation ICDs do not have automatic HV testing (Atlas/Epic) • Automated HVLI testing in later generations St. Jude Medical. Riata Lead Summit 1/12
- 40. Detection of Riata/ST Failures • Earlier generation ICDs do not have automatic HV testing (Atlas/Epic) • Automated HVLI testing in later generations St. Jude Medical. Riata Lead Summit 1/12 St. Jude Medical. Riata Lead Summit 1/12
- 41. St. Jude Medical. Riata Lead Summit 1/12
- 42. Riata/ST High Voltage Failure What do the large trials tell us? Trial #patients #/% Electrical Failures #/% of electrical that are HV VA1 1403 47 (3.4%) 3 (6.3%) Canadian2 4358 201 (4.6%) ?? >= 1 HV failure US Multicenter3 1081 67 (6.2%) 3 (4.4%) St. Jude Riata LES4 776 10 (1.3%) 5 (50%) 1. Sung et al. Heart Rhythm 2012 9:1954-1961 2. Parkash et al. Heart Rhythm 2013 10: 692-695 3. Abdelhadi et al Heart Rhythm 2013 10: 361-365 4. Hayes et al. Heart Rhythm 2013 10: 1778-1782 50% of detected failures were in HV circuit
- 43. Heart Rhythm 2013 10: 1778-1782 • Prospective 782 pts: followed avg 9.8 months • Baseline fluoroscopy and serial electrical testing • Average lead age--Riata 6.5 yr, Riata ST 4.8 yr • “Potential” HV failure defined as • HVLI change >25 Ω or • HVLI >125Ω or <20Ω • 5 of 10 adjudicated electrical failures were HV • Additional 4 leads had HVLI change >25 Ω but adjudicated as normal function
- 44. Danish Riata Registry • 295 mature Riata Leads (5.1 +/- 1.1 yr) • Baseline fluoro, prospective F/U (1.1 yr) • 6.5% electrical abnl (21.9% w/EC, 5.3% wo/EC) Only 51% of leads had high voltage testing performed - Low incidence of HV failures (high impedance) - No instances of HV insulation (low impedance) failure detected - No low impedance pace failures in EC group Heart Rhythm, In Press
- 45. How Well are we Detecting Riata High Voltage Failures?
- 46. • 77 year old man, ischemic cardiomyopathy • EPIC DR ICD with Riata 1580, externalized, No HVLIs • Gen change to Fortify DR. HVLI normal at 39 Ω • VF induced with 1 J T shock • 20 J shock failed, external defib, ICD system error • HVLI repeated, still normal at 35 Ω • 20 J shock failed, external defib, ICD system error • HVLI now <10 Ω, no sensing issues
- 47. Short evident between SVC coil and RV shock cable
- 48. Doshi Case - Riata HV Insulation Short #2 SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 2 RV HV cable to SVC coil short ICD Can Lead failure repeatedly not evident by low voltage testing
- 49. Tip of the Iceberg? • 3 similar case reports in the literature1,2,3 – HV failure at shock with normal low voltage testing • Hauser analysis of MAUDE database4 reported 91% of Riata related deaths were due to HV failure • Hauser reported abrasion failures of Durata5 1) Leong et al, PACE, June 2012 2) Shah, et al, JCE January 2013 3) Marenco PACE 2013 4) Hauser Heart Rhythm August 2012 5) Hauser Europace, February 2013
- 50. Thomas Hawk: Flikr.com shared under Creative Commons license
- 51. Tip of the Iceberg? “Crash Testing” AHA Scientific Sessions 2012 • 90 Riata/ST pts underwent fluoro and HV shock • 51% externalized conductors • 9% (8 pts) failed shock testing (8/9 not externalized) • HV failure defined as failure to induce/sense/shock VF
- 52. Tip of the Iceberg? “Crash Testing” HRS Sessions 2013 • 289 Riata/ST patients evaluated • Mean implant time 5.7 years • Externalization by CXR: 13.1% Riata, 4.8% Riata ST • 116 patients underwent DFT test at max output • 1 Riata patient (1%) failed to rescue with initial shock (HV <10%)
- 53. Riata Evolution to Durata RV ring P/S Cable SVC HV Cable RV HV Cable RV tip filament 1) RV HV cable to can 2) RV HV cable to SVC cable or coil 3) RV Ring P/S cable to RV HV cable and RV ring to can 1z 2 3 ICD Can 3 Optim outer insulation added with Durata
- 54. Durata ICD Lead Performance
- 55. Durata ICD Lead Performance • Cairns et al report results of three active St. Jude managed registries on Optim ICD leads • 11,016 leads • Mean Follow up 3.2 years • Independent review by Canadian Investigators • 51 mechanical failures (0.46%), 99% survival • No externalized leads
- 56. Criticisms of Optim ICD Lead Registry • 22.9% drop out due to missing data • 3.3% of leads taken out of service seems high compared to 0.46% failure. Why? • 19.2% death or transplant. No report of post mortem interrogations. No way to exclude lead failure as cause of death. • 39% of the leads with mechanical failure had returned product analysis. Is this too high?
- 57. Durata High Voltage Failure PACE. September 2013 • 55 yo male with Current DR, Durata lead, 12/09 • NS VF episode detected, therapy diverted. EGM shows noise on RV P/S and RV HV, not on RA • To ER w/vibrating ICD in backup mode. HV therapies disabled and no programmability
- 58. Durata High Voltage Failure • In lab: Normal sensing/threshold/Ω/fluoro • No noise could be reproduced, appearance OK • New Fortify DR ICD: • 20 J synchronized test shock successful • VF, 36 J shock failed, audible “pop” • Still in VF, 40J shock failed, backup mode • New lead & 2nd PG placed, VF test successful
- 59. Durata High Voltage Failure A sense RV coil-can RV sense Simultaneous noise on RV shock coil-can and RV sense electrodes with normal atrial sensing RV shock coil to RV cable short
- 60. Durata High Voltage Failure #3 SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 1) RV HV cable to can 2) RV HV cable to SVC cable or coil 3) RV Ring P/S cable to RV HV cable and RV ring to can ICD Can 3 3 Optim Insulation
- 61. Durata High Voltage Failure https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/Detail.cfm?MD RFOI__ID=3669333
- 62. • 49 yo woman w/hypertrophic cardiomyopathy • Current DR with Durata 7120 placed 7/08 • Normal office follow up (low and high voltage) Heart Rhythm, October 2014
- 63. Durata High Voltage Failure • 12/13, arrest at work. 15 min bystander CPR, Squad shocked VF multiple times, hypothermia • ICD evaluation: – HV impedance <10 Ω (vector not specified) – HVLI and pace/sense evaluation normal • Durata Lead extracted • No visual or fluoroscopic abnormalities in lab • New Medtronic ICD lead and PG placed Heart Rhythm, October 2014
- 64. Durata HV Failure Electrically silent inside out abrasion of Durata RV conductor cable under SVC coil near fatal shock failure Personal communication and chart review, M. Gupta MD. The Christ Hospital, Cincinnati, OH
- 65. Durata HV Failure Electrically silent inside out abrasion of Durata RV conductor cable under SVC coil near fatal shock failure Heart Rhythm, October 2014 RV conductor Cable SVC Coil
- 66. Durata High Voltage Failure #2 SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament RV HV cable to SVC Coil ICD Can 2
- 67. New St Jude System Enhancements SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 2 ICD Can 3 1 3 A) Parylene Coating on ICD can with Elipse PG B) Additional Optim layer from proximal end to SVC coil with Optisure Lead C) Dynamic Tx provides shock vector switching with detection of insulation breach
- 68. High Voltage ICD Lead Failure • Underappreciated and potentially fatal • Can present with no change in painless HV impedance or any other parameters measured in ICD follow up • Presentation varied and at times very complex • Existing means of detection are inadequate • Open question: Do we need to change our follow up strategies?
- 69. High Voltage ICD Lead Failure Suggestions • We need to encourage post-mortem interrogation ICD patients. This should be required in registries and pre market trials. • Support investigation of St. Jude leads for high voltage performance - “Crash Test” trial. • Encourage a protocol for assessment of St. Jude ICD leads at device replacement.
- 70. Thank you!
- 71. Backup Slides
- 72. Riata Failures in Danish Registry EC= Externalized Conductors • No low impedance high voltage failures in EC or no EC groups • Low impedance failure in pace/sense electrode seen only in no EC group Larsen et al HRS abstract 2014
- 73. Thomas Hawk: Flikr.com shared under Creative Commons license
- 74. Airbag Reliability • 100 drivers – 10 get in accident • 9 effective airbag deployment • 1 driver dies with ineffective airbag • What is the airbag failure rate? – 1% or 10%?
- 75. Riata HV Insulation Shorts SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 1) RV HV cable to can 2) RV HV cable to SVC cable or coil 3) RV Ring P/S cable to RV HV cable and RV ring to can z1 2 ICD Can 3 3
- 76. Riata Evolution to Durata RV ring P/S Cable SVC HV Cable RV HV Cable RV tip filament 1) RV HV cable to can 2) RV HV cable to SVC cable or coil 3) RV Ring P/S cable to RV HV cable and RV ring to can z1 2 3 ICD Can 3 Optim outer insulation added with Durata
- 77. New St Jude System Enhancements 3 1 SVC HV Cable 2 RV HV Cable RV ring P/S Cable RV tip filament 3 ICD Can A) Paraylene Coating on ICD can with Elipse PG B) Additional Optim layer from proximal end to SVC coil with Optisure Lead 1) RV HV cable to can 2) RV HV cable to SVC cable or coil 3) RV Ring P/S cable to RV HV cable and RV ring cable to can
- 78. Riata HV Insulation Shorts #3A 3 SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 1) RV HV cable to can 2) RV HV cable to SVC cable or coil 3) RV Ring P/S cable to RV HV cable and RV ring to SVC coil/cable ICD Can 3
- 79. Riata HV Insulation Short #3b 3 3 SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 1) RV HV cable to can 2) RV HV cable to SVC cable or coil 3) RV Ring P/S cable to RV HV cable and RV ring to RV tip and RV tip to can ICD Can 3
- 80. Mitigation of Failure #2 with SVC Reprogramming SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 2 RV HV cable to SVC cable or coil ICD Can
- 81. Mitigation of Failure #2 with SVC reprogramming SVC HV Cable RV HV Cable RV ring P/S Cable RV tip filament 2 RV HV cable to SVC cable or coil ICD Can SVC Programmed off Shorted SVC current blocked at can. Shock impulse arrives at heart, grounds to can.
- 82. JCE January 2013 • 72 year old with CAD, sustained VT • ICD 2004: 1580 Riata. Gen change 2009 Current Plus, VF induced & terminated with 20 J shock • 2012 SVT episode. 25 J charge but shock truncated with HV Ω <10J. SVT terminated spontaneously • All HV parameters normal – HVLI 44Ω
- 83. JCE January 2013 • Fluoro showed externalization between shock coils • DFT test: 20 J shock truncated with HV <10 Ω. Pt externally defibrillated
- 84. Riata/ST High Voltage Failure What do the large trials tell us? • VA Trial Sung et al– Total electrical Failure 3.7% (47/1403). HV failure 3 (6%/0.2%)* * (% of population/% of failed leads)
Editor's Notes
- #8: Do we know how all of our ICD patients die? Note boxes of ICDs in funeral homes. Note boxes of ICDs in funeral homes. Note boxes of ICDs in funeral homes.
- #9: Recognize HV failure may be picked up in association with PS failure (i.e. Riata/Durata) Note the limitation of patient ability to pick up warnings. This is not LIA alert. Maybe St. Jude vibratory alarm would be improvement.
- #10: Both of these first depend upon the quality of our office HV testing (as will be discussed)
- #11: Cite SIMPLE trial here. Recall in early 90s and early 2000s, annual DFTs common. Now even 1st DFT becoming rare. Reserved for specific situations such as a concern over lead status (not Curtis is a co-author of RLES – no Defib testing
- #13: Recognize these failures may go undetected. They reside in the morgue or in the MAUDE database. Post mortem interrogations are infrequent. Imagine a fatal car accident in which EMS does not analyze the functioning of the airbag. It is to the credit of his doctors that this recognized.
- #14: I’m not aware of any examples of PG falure that specifically knocks out shock delivery. [ask industy]
- #15: Also mention header/lead midmatch
- #17: We’re gonna breeze right through these since these will be available on the USB stick.
- #19: What are the min/max values?? Is there a low impedance alarm
- #20: Request of White Paper sent to Trish Craft. Repeated requests to St. Jude engineering were not addressed. MD delivered HVLI is somewhat jarring to patient
- #21: FAST FAST FAST FAST FAST
- #22: FAST FAST FAST FAST FAST
- #24: Conductor failure is the good one. Easier to pick up on non-shock testing. SVC may be completely harmless, even if undetceted. Bad news if RV fractures and is not picked up prior to a VF episode
- #25: These are tricky. Tough to detect, potential to destroy device. Recognize limitations of Dynamic Tx – only useful with dual coil lead. May be appropriate to leave SVC coil on if you have Dynamic TX x
- #26: In the early era of ICD leads, insulation failure was dominant mechanism of failure. Later multilumen leads and improved materials caused these failures to diminish. http://circ.ahajournals.org/content/115/19/2474.long Brief mention here of Transvene failures in a tripolar design. Signature defect of Transvene – P/S noise shows up after a shock – per Ellenbogen Failure is silent until a shock is delivered. May be a lesson for Riata.
- #27: Background on Fidelis, then we’ll talk about detection High voltage failure is not only tough to detect, it’s also tough to study. PPR is no help. Need to go to other sources to determine HV failure rate
- #28: 3 centers, 1023 Fidelis leads. 2.8% failure/year. 95% LV, 5% HV Quattro 0.43% failure/year. 83% LV, 17% HV
- #30: TAKE HOME POINT. IF HV TRIGGER 100, WILL CATCH ALL OF THESE. Nominal impedance trigger of 200 ohm may be insensitive.
- #31: FAST FAST FAST FAST FAST FAST FAST FAST
- #32: FAST FAST FAST FAST FAST FAST
- #33: BREEZE THROUGH. KEY POINT IS INSULATION MAIN ISSUE.
- #35: Set the stage. Common
- #36: All failures include a short between RV HV limb and either SVC or Can. Didn’t include crush injury or lead/lead interaction in this discussion Could mitigate with turning off can.
- #37: Mechanism #2 has a programming fix. Also, Dynamic Tx will handle this.
- #38: There are other variations of this mechanism. Involves Pace/Sense Circuit
- #39: Describe HVLI testing. You may have patients in your practice who have not had a current passed over their HV component for years.
- #41: Seen in association with a P/S failure. This one is a lot more subtle. The red box is St. Jude’s, not mine. Remember this when we look at the RLES data.
- #42: Pretty labor intensive. No automation to the EGM retrieval so may be easy to miss events visible on the EGM. No events, then no EGMs. Tight HVLI intervals may be tough to visualize. Wonder about specificity of changes
- #43: Note high proportion of HV. These are the patients you are dealing with TODAY. That’s why it is so critical we have this session Most of the faculty here today is represented in these studies
- #44: UPDATED AT THURSDAY”S ABSTRACT SESSIONS RLES is a incidence trial, not a prevalence trial Take home message: High prevalence of HV in failed leads in this population. Defining HV was difficult. NO SHOCK TESTING DONE
- #45: Only 51 % of leads had HVLI testing
- #46: That begs the question ----
- #49: Turning off SVC coil in system may render this mode of failure clinically insignificant
- #50: Many more MAUDE failures if you look for them. I have examples
- #52: BIG CENTERS NEED TO REPEAT THIS STUDY
- #53: BIG CENTERS NEED TO REPEAT THIS STUDY
- #54: NO OPTIM UNDER SHOCKING COILS
- #58: DATE OF EVENT IS NOT IN CASE REPORT Noise could not be reproduced in office. Extended detection, tightened impedance alerts, scheduled imaging and close f/u
- #59: Device didn’t fail until 2nd shock. Recall Doshi case in which 1J T shock was OK. Sometimes lead won’t fail until repeated HV stressor
- #60: Durata Lead not extracted. No RPA. Discussed similarity to Swerdlow case.
- #61: Alternatively could have SVC coil short. Has to be two failure points.
- #62: Failure mechanism #3 was seen in Goldstein Durata case in which can was
- #64: Was she on remote follow up??? Primary prevention. FHx SCA (mother). Device placed at CCF. Active, does daily treadmill exercise. Arrested at outlet mall. 15 min bystander CPR prior to defibrillation. Hypothermia protocol.
- #65: No details on Pre op ICD testing other than HV <10 ohms, no vector specified. Rep programmed SVC coil out but said lead may still fail. In lab, no intraop electrical details recorded. Don’t know if pt felt a vibratory alert.
- #66: Entirely predictable. In fact, I predicted at the Riata Summit. Link up on my twitter at #HRS2014 Should vendors report sentinel events --- perhaps to an independent board?
- #67: Entirely predictable. In fact, I predicted at the Riata Summit. Link up on my twitter at #HRS2014 Should vendors report sentinel events --- perhaps to an independent board?
- #69: Failure mechanism #3 was seen in Goldstein Durata case in which can was
- #70: Program out SVC – not controversial. Will be able to eliminate one mechanism. Annual high voltage stressor to lead – Willl require consensus TRIAL NEEDS TO BE DONE!!!! Industry needs to design HV failure detection algorithms.
- #71: Program out SVC – not controversial. Will be able to eliminate one mechanism. Annual high voltage stressor to lead – Willl require consensus TRIAL NEEDS TO BE DONE!!!! Industry needs to design HV failure detection algorithms.
- #74: Ask all: have you ever seen low voltage HV failure before catastrophic failure? Provocative hypotheses: We cannot detect low impedance (abrasion) high voltage failure Externalization may protect from abrasion injury (not no low impedance events of any sort in the EC group if the cables are able to make it out without injury, they do OK The abrasion occurs when constrained inside the lead. Does this have implications for Durata?
- #77: Failure mechanism #3 was seen in Goldstein Durata case in which can was Should I include a dot in #3 at the RV ring to can site? Other scenarios possible with widespread abrasion in the can
- #78: Failure mechanism #3 was seen in Goldstein Durata
- #79: Failure mechanism #3 was seen in Goldstein Durata case in which can was
- #80: There are other variations of this mechanism.
- #81: There are other variations of this mechanism.
- #82: Failure mechanism #3 was seen in Goldstein Durata case in which can was Should I include a dot in #3 at the RV ring to can site? Other scenarios possible with widespread abrasion in the can
- #83: Failure mechanism #3 was seen in Goldstein Durata case in which can was Should I include a dot in #3 at the RV ring to can site? Other scenarios possible with widespread abrasion in the can SVC coil will shunt current
- #84: Don’t forget Durata Goldstein case. ? RV coil/RV ring
- #85: Don’t forget Durata Goldstein case. ? RV coil/RV ring
- #86: Not exhaustive list VA trial senior author is Keung, our session chair