2 Up to 21% of ICD Patients Receive Inappropriate Shocks1-4 Suggested Questions for Physician:•On average what do you think is the incidence of inappropriate shocks?What percent of your patients do you think receive inappropriate shocks?Say:Large trials have shown that the occurrence of shocks (both inappropriate and appropriate) are high. And this is not dependant on the type or on the brand of device used.Your Objective:Help physicians identify the need for reducing inappropriate shock with published industry-wide data of incidence of inappropriate shocks.Physician Key Take-away:With current technologies inappropriate shock is a significant industry wide problem.Backup information:Madit II (Multicenter Automatic Defibrillator Implantation Trial II) was studying Primary Prevention patient with MI (at least 30 days) and depressed EF (< 30%) comparing Optimal Medical Treatment ICD was proven effective in reducing all cause mortality by 31. However:- 83 pts out of 719 ICD pts (11.5%) received one or more inappropriate shocks- 184 out of 590 shocked episodes (31.2%) were inappropriateDEFINITE (Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation) was aimed to study the value of prophylactic implantation of an ICD to prevent sudden death in patients with nonischemic dilated cardiomyopathy (EF < 36%, PVC). The study showed that the implantation of an ICD significantly reduced the risk of sudden death from arrhythmia and was associated with a non significant reduction in the risk of death from any cause. In the trial the percentage of inappropriate shocks was superior than the percentage of appropriate shocks (21% vs 18%)SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial) was aimed to determined if amiodarone or ICD will decrease the risk of death from any cause in patients with mild-to-moderate heart failure (CHF ≥ 3 months, NYHA Class II and III, LVEF ≤ 35%, ischemic and non ischemic). The study proved that ICD decrease mortality by 23% and Amiodarone, when used as a primary preventive agent, does not improve survival. However:- 17.4% of patients (141 out of 811pts) received one or more inappropriate shocks- 87 pts out of 269 pts (32.3%) that received any shocks received only inappropriate shocksALTITUDE is an observational study designed to determine the mortality outcomes and incidence of appropriate and inappropriate shock therapies in a large cohort of ICD and CRT-D recipients treated in naturalistic practice. The trial showed that shock is associated with decreased survival for both ICD and CRT patients (HR = 1.60, p < .0001). The 5-year incidence of shock is 35.5% for ICD and 34.5% for CRT patients.- 43% of the shocks were classified as inappropriate by the independent adjudication panel1 Kadish A, Dyer A, Daubert JP, et al, for the Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation (DEFINITE) Investigators. Prophylactic defibrillator implantation in patients with nonischemic dilated cardiomyopathy. N Engl J Med. May 20, 2004;350(21):2 Daubert JP, Zareba W, Cannom DS, et al, for the MADIT II Investigators. Inappropriate implantable cardioverter-defibrillator shocks in MADIT II: frequency, mechanisms, predictors, and survival impact. J Am Coll Cardiol. April 8, 2008;51(14):3 Poole JE, Johnson GW, Hellkamp AS, et al. Prognostic importance of defibrillator shocks in patients with heart failure. N Engl J Med. September 4, 2008;359(10):4 Mitka M. New study supports lifesaving benefits of implantable defibrillation devices. JAMA. July 8, 2009;302(2):
3 Why Avoiding Shocks Is Important To Reduce Pain and Anxietyand Increase Device Acceptance1To Reduce Healthcare Burden and Improve Patient Quality of Life1Avoiding Shocks May Improve Survival/Heart Failure2Suggested Questions for Physician:What is the impact of inappropriate shocks on your patients QOL?How do you feel when your patient receives an inappropriate shock?What is the impact of inappropriate shocks on your practice?How do you think inappropriate shocks affect your patients’ risk of increased mortality?Are you familiar with recent evidence about the effects of shocks on mortality?How often do you think that some referring physicians do not refer patients for an ICD because they fear patients will receive inappropriate shocks?What % of patients might refuse to get an ICD because they’re concerned about receiving an inappropriate shock?Your Objective:Help your physician realize the negative consequences of (inappropriate) shocks.Physician Key Take-aways:Shocks affect patient’s QOL, hospital and clinician burden and may increase mortality risk.Backup information:ICD shocks for VF save lives when no other therapy type is effective. However, recent evidence indicates an association between shocks and increased mortality risk.Dr. Sweeney’s article published in HRJ in March 2010 analyzed over 2000 patients from PainFREE 1, PainFREE 2. EMPIRIC and PREPARE studies. It shows that patients with shocked ventricular arrhythmias had 20% increased mortality risk per shocked episode compared to patients treated only with ATP. In his analysis however, inappropriate shocks are not linked to increased mortality. His conclusion is that strategies to minimize shocks may further improve survival in patients because we almost exclusively treated patients with shocks in trials that demonstrated the mortality benefit of ICDs.• Dr. Poole JE article published September 2008 in NEJM links all ICD shocks (appropriate and inappropriate) in SCD-HeFT to increased mortality. No evidenceof causal relationship.• Dr. Daubert article published April 2008 in JACC links all cause ICD shocks – not ATP – to increased mortality in MADIT-II.1 Wathen MS, DeGroot PJ, Sweeney MO, et al, for the PainFREE Rx II Investigators. Prospective randomized multicenter trial of empirical antitachycardia pacing versus shocks for spontaneous rapid ventricular tachycardia in patients with implantable cardioverter-defibrillators: Pacing Fast Ventricular Tachycardia Reduces Shock Therapies (PainFREE Rx II) trial results. Circulation. October 26, 2004;110(17):2 Sweeney MO, et al. Differences in effects of electrical therapy type on health care utilization in the MVP ICD Trial. HRS, 2010.
4 20 Years of Leadership in Shock Reduction It Is Time to Redefine the ICD Say:For the past two decades, Medtronic has been a leader in reducing shocks.Medtronic has funded all major shock reduction trials involving over 5500 patients and hundreds of centers around the world. These studies were designed to improved device programming to decrease inappropriate and unnecessary shocks. As a result new technology was developed and made nominal in our devices such as ATP During Charging, consistent and short charge times, LIA, PR Logic, Wavelet…Protecta is a new era in shock reduction. Protecta’s goal is to not just decrease inappropriate shocks, but to eliminate them whenever possible.Suggested Question for Physician:• How satisfied are you with the current solutions for minimizing inappropriate shocks with regard to your current patient population (primary and secondary prevention patients)?Your Objective:To ensure the physician understands Medtronic’s history and commitment to develop innovative solutions to reduce unnecessary and inappropriate shocks.Protecta SmartShock solutions have been in development for >5 years using knowledge and evidence from studies such as SCD-HeFT, EMPIRIC, PainFREE Rx II, WAVE, and PREPARE.Physician Key Take-aways:Inappropriate shock reduction (or elimination) is becoming increasingly important given the high percentage – 80% – of primary prevention patients receiving ICD therapy. It is time for a new era of ICDFor the past two decades, Medtronic has been a leader in reducing inappropriate shocks.1 Wathen M. Implantable cardioverter defibrillator shock reduction using new antitachycardia pacing therapies. Am Heart J. April 2007;153(4 Suppl):44-52.
5 With Protecta™ XT 98% of Patients are Free of Inappropriate Shocks at 1 Year1 and 92% at 5 Years1 Suggested Question for Physician:What would you consider a significant improvement in minimizing the number of patients receiving inappropriate shocks (1-5 years timeframe)?Say:Compared to the current incidence of 20 to 30% of patients receiving an inappropriate shock over the life of the device, we estimate that with Protecta device, at least 90% of patients will be free of inappropriate shocks over the life of the device.1-5We used a very sophisticated statistical model to run SCD-HeFT episodes through the Protecta SmartShock technology and estimate the shock reduction gain.After looking at these results, is this a significant improvement over current technology available?Your Objective:Demonstrate the proven efficacy of Protecta in effectively reducing inappropriate shocks.Physician Key Take-aways:With Protecta XT 98% of patient are free of inappropriate shocks at 1 year and 92% at 5 years. Virtual ICD: A Model to Evaluate Shock Reduction Strategies. Presented at HRS 2010 (P03-125).References1. Kadish A, Dyer A, Daubert JP, et al, for the Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation (DEFINITE) Investigators. Prophylactic defibrillator implantation in patients with nonischemic dilated cardiomyopathy. N Engl J Med. May 20, 2004;350(21): Daubert JP, Zareba W, Cannom DS, et al, for the MADIT II Investigators. Inappropriate implantable cardioverter-defibrillator shocks in MADIT II: frequency, mechanisms, predictors, and survival impact. J Am Coll Cardiol. April 8, 2008;51(14): Poole JE, Johnson GW, Hellkamp AS, et al. Prognostic importance of defibrillator shocks in patients with heart failure. N Engl J Med. September 4, 2008;359(10): Mitka M. New study supports lifesaving benefits of implantable defibrillation devices. JAMA. July 8, 2009;302(2): Virtual ICD: A Model to Evaluate Shock Reduction Strategies. Presented at HRS 2010 (P03-125).1 Virtual ICD: A Model to Evaluate Shock Reduction Strategies. Presented at HRS 2010 (P03-125).
6 SmartShock™ Technology Dramatically Reduces the Incidence of Inappropriate Shocks While Maintaining Sensitivity1,2Questions for Physician:In your opinion what do you think are the major causes of inappropriate shocks?What would you consider a significant improvement in minimizing inappropriate shocks (5 years timeframe)?Say:When developing this new device, we looked at the various causes of shocks and addressed them one by one with new algorithms. We have made a lot of progress in the last 10 years at reducing shocks for true VT/VF with ATP but the incidence of inappropriate shocks is still too high. When you look at the percentage of shocks that are due to SVT, Oversensing or Non Sustained VT, we will be able to significantly reduce that number.SmartShock Technology is unique in the fact that it addresses ALL major causes of inappropriate shocks (SVT, NSVT, T-wave, Noise).SmartShock Technology includes PROVEN Discriminators that do not require programming, so don’t reduce VT/VF sensitivity.SmartShock Technology ADJUSTS according to patient’s individual needs.Your Objective:Compare the % of inappropriate shocks with and without SmartShock Technology.Physician Key Take-aways:SmartShock is exclusive technology with superior discriminating algorithms that can discriminate true lethal arrhythmias from other arrhythmic (SVT, AT/AF, NSVT) and non-arrhythmic events (oversensing, noise)1 Virtual ICD: A Model to Evaluate Shock Reduction Strategies. Presented at HRS 2010 (P03-125).2 Protecta Clinical Study, Medtronic data on file.3 Poole JE, Johnson GW, Hellkamp AS, et al. Prognostic importance of defibrillator shocks in patients with heart failure. N Engl J Med. September 4, 2008;359(10): t
7 SmartShock™ Technology Includes 6 Exclusive Algorithms that Discriminate True Lethal Arrhythmias from Other Arrhythmic and Nonarrhythmic Events1Suggested Questions for Physician:How do you use current technology to address all major causes of inappropriate shocks (SVT, AT/AF, NSVT, oversensing, noise)?What do you have to do with current technology in order to address inappropriate shocks? Can you do this pro-actively?Your Objective:Demonstrate that SmartShock technology addresses all the major causes of inappropriate shocks;easily – automatic and nominally on –effectively – no compromises on detection of real VT/VFPhysician Key Take-aways:SmartShock Technology is a complete set of algorithms to address the major causes of inappropriate shocks.See Protecta XT CRT-D, DR, and VR Clinician Manuals for technical details1 Virtual ICD: A Model to Evaluate Shock Reduction Strategies. Presented at HRS 2010 (P03-125).2 Poole JE, Johnson GW, Hellkamp AS, et al. Prognostic importance of defibrillator shocks in patients with heart failure. N Engl J Med. September 4, 2008;359(10):
8 First and Only T-wave Discrimination Identify T-wave oversensing and provide ability to withhold therapy delivery without compromising VT/VF detection sensitivityNew approach to T-wave oversensing:Frequency analysis versus manual sensitivity adjustmentFully automaticDoes not require an initial shock for T-wave oversensingNo compromise on VF detection sensitivityR/TVSVtip-Vring EGMSense EGMd/dt(Sense EGM)RTSense EGM: In current devices, signal is filtered to isolate R-waves. May oversense T-waves.Say:Medtronic has developed the first T-wave OS discrimination algorithm.It takes a completely different approach to T-wave oversensing compared to other algorithms on the market that work by manually adjusting the sensitivity. The problem with these algorithms is that they compromise the sensitivity and require manual adjustment as the patient t-wave changes over the life of the device.This discriminator reviews the pattern of the R and T senses, identifies T-wave oversensing and withholds therapy without compromising VT/VF detection sensitivity.Benefits:No need for patient to experience an inappropriate shock so that programming can then be done to reduce inappropriate shockFully automatic: No manual adjustment needed over the life of the patientNo risk of under-detecting VFHow it works:If T-wave oversensing occurs and forces rates into the VT or VF zones, the device uses a filtered version of the RVtip/RVring EGM and to analyze the frequency and pattern of the R and T-wave senses.T-waves are composed of lower-frequency components than R-wavesVF waveform morphology characteristics do not allow for establishment of R-T patternDifferentiation of sense amplifier output (sense EGM before rectification) enlarges the ratio of R-to-T-wave amplitudes, enabling R-T pattern recognitionIdentify sensed T-waves by analyzing R-T pattern and withholding detectionT-wave Discrimination works on redetectionThe device continues to monitor the signal for changes in the rhythm and will redetect and deliver therapy if needed. Note that this algorithm does not eliminate T-wave oversensing but recognizes it to reduce the chance of inappropriate shocks.The T-wave oversensing discrimination algorithm is nominally programmed on in Protecta. When a T-wave pattern is identified, the episode will be logged in the device and the EGM and marker channels can be reviewed at a device interrogation.In Protecta™, differentiation of sense EGM enlarges the ratio of R-to-T-wave amplitudes, enabling R-T pattern recognition.
9 Compares far-field cardiac activity to sensed event Lead Integrity SuiteCombines 2 algorithms that detect, alert, and withhold inappropriate therapy for lead failure,Lead Integrity AlertProvides advanced warning for lead fracture and extends the VF detection timeLead Noise Discriminator + AlertIdentifies oversensing due to noise artifacts and provides ability to withhold therapy deliveryNo compromise of VT/VF detection sensitivityNotifies clinician to potential lead noiseSay:The lead integrity suite consists of two algorithms which alert the patient and clinic (via Carelink) of the potential for lead noise and lead failure and withhold therapyLead Integrity Alert is already available. RV Lead Integrity Alert provides advance warning for lead fracture and extends the VF detection time to 30/40 beats. This algorithm monitors the lead impedance, the new episode log called High-Rate NS, and short interval counter and produces an audible alert and a CareAlert. This allows for advanced warning of potential lead fractures so that the patient can seek medical attention and reduce the risk of receiving a shock. However, it does not withhold therapy.RV Lead Noise Discrimination identifies oversensing due to noise artifacts and withholds therapy without compromise of VT/VF detection sensitivity. It does so by validating the near field signal (such as RVtip/RVring) to a far field signals (such as Can/RVcoil). Sensed events with no corresponding activity on far-field electrogram are indicative of oversensing. True VT/VF is confirmed by analyzing sensed events to activity on the far-field electrogram. It sends an alert if detection is withheld.Benefits:RV Lead Noise Discrimination and Alert – Identifies oversensing due to noise artifacts and provides ability to withhold therapy delivery.No compromise of VT/VF detection sensitivityNotifies clinican to potential lead noiseLead Integrity Alert – Provides advanced warning for lead fracture and extends the VF detection timeHow Lead Noise Discriminator works:The algorithm looks at a series of senses and determines the amplitude difference of the senses on the far field signal.Some of these senses will coincide with an R-wave and therefore have a high amplitude while many of the senses will have baseline amplitude.The average of the two smallest amplitudes in that series must be less than 1/6th the maximum amplitude in order for the algorithm to determine that the oversensing is due to noise only apparent on the near field signal. This pattern also must be sustained over time.Once VF detection is met, the device makes a determination based on this evidence on whether to withhold or deliver therapy.If therapy is withheld, the device continues to monitor sets of ventricular senses to ensure that therapy is delivered in a timely fashion should a true arrhythmia occur. The discrimination algorithm is eliminating multiple inappropriate shocks for lead noise but the lead noise may indicate a more serious lead issue, necessitating medical attention.Alerts:These two lead noise algorithms are programmed nominally on in the device.The audible alerts are also programmed on nominally. Choosing “Yes” for Patient Home Monitor will cause the CarelAlert notification functionality to be turned on as well. Note that the patient needs to be registered on Carelink and have a Carelink box set up at their home for the CareAlert to properly transmit.If either lead noise algorithm is triggered, an observation will appear on the quick look screen. Additionally, an EGM will be collected for assessment. The purpose of these notifications is to notify the patient and the medical staff that an ongoing lead issue is occurring.Compares far-field cardiac activity to sensed event
10 + PR Logic® + Wavelet PR Logic Wavelet Discrimination in the Combines morphology and A-V pattern recognition to better discriminate against all types of SVTs – even the very fast ones+PR LogicEffectively discriminates Sinus Tach and most AF/A FlutterWaveletUses EGM morphology to improve SVT discrimination (i.e., conducted AF and sudden onset SVT)Say:PR Logic and Wavelet SVT discriminators have been available in Medtronic devices for many device generationsPR logic in dual chamber devices uses the atrial and ventricular sense markers to review the rhythm pattern.Wavelet in single chamber devices looks at EGM morphology to determine the origin of the waveform (ventricular or supraventricular).Protecta now offers added protection against SVTs by adding Wavelet to PR logic in both dual chamber and triple chamber (CRT) devices.The addition of Wavelet to the SVT discrimination logic will allow rhythms which are misclassified by PR logic (such as sudden atrial tachycardias) to be reclassified by Wavelet so that a shock is appropriately withheld.For CRT-D: manual template collectionSVT Limit = reduced nominally to 260 ms (from 320ms); VF High-Rate TimeoutPR logic and Wavelet only work as fast as the SVT limit (shortest interval that will be reviewed by these SVT discriminators)Timeout addresses concerns about sustained high rates for long period of timeIn VR: nominal is 45 secondsIn DR: nominal is OFFIn dual chamber and CRT devices, both PR logic and Wavelet are ON when VF is programmed to ON.The user has the ability to program either or both of the algorithms off at an interrogation.Diagnostics are available for any rhythm classified by PR logic or Wavelet. The EGM, classification details, as well as QRS snapshots (for template comparison) can be reviewed.Benefits:PR Logic+Wavelet in DR and CRT-D devices – combines morphology and A-V pattern recognition to better discriminate against all types of SVTs – even the very fast ones.PR Logic - Effectively discriminates Sinus Tach and most AF/A flutterWavelet – uses EGM morphology to improve SVT discrimination (i.e. conducted AF and sudden onset SVT)Enhanced Discrimination in the VF ZoneSVT Limit nominal change to 260 msHigh rate time-out in the VF zoneHow it works:The combined detection algorithm includes the four PR Logic criteria plus the Wavelet criterion as the lowest priority SVT criterion. The PR Logic double tachycardia criterion was modified to require abnormal morphology, and the Wavelet criterion was modified to apply only when the V-V intervals > A-A intervals.Wavelet also works the same in Protecta as it does in recent devices. Wavelet collects a normal sinus rhythm template and then compares that template to the morphology of the EGM collected at the time of the fast detected rhythm. If at least three out of the eight beats prior to detection match the template, then the rhyhtm identified as a SVT.Again, the rhythm is continually monitored for changes.Discrimination in theVF zone (nominal)SVT Limit = 260 msVF High-Rate Timeout
11 Confirmation now available after ATP During Charging™ sequence Better identifies that a tachycardia has been terminated with ATP or spontaneously during the charge and aborts the shockAvoids inappropriate shocks for single PVCs or single fast events at the end of the chargeCONFIRMATIONConfirmation +Modify determination of persisting arrhythmia based on intrinsic detected rate versus programmed lower therapy rate (sync interval)Say:Confirmation+ identifies that a tachycardia has been terminated with ATP or spontaneously during the charge and aborts the shock. It avoids inappropriate shocks for single PVCs or single fast events at the end of the charge. It modifies determination of persisting arrhythmia based on intrinsic detected rate vs. programmed lower therapy rate (sync interval).Benefits:Improve shock delivery specificity adopting the strategy mentioned above.Modify evaluation of a rhythm as “ongoing” or “terminated” from a value based on programmed detection intervals to value based on the detected arrhythmia cycle lengthBetter identifies that a tachycardia has been terminated with ATP or spontaneously during the charge and aborts the shockAvoids inappropriate shocks for single PVC or single fast events at the end of the chargeHow it works:When an arrhythmia is detected and breaks spontaneously or when ATP breaks an arrhythmia during a charge, the device needs to review the rhythm to confirm the presence of VF in a short amount of time at the end of the charge and decide whether to abort the scheduled shock.It delivers a shock only if the rate during reconfirmation period is within 60 ms of the detected rhythm.Protecta includes a new adaptable algorithm which reviews the cycle length of the arrhythmia before detection and sets an interval criteria for aborting the shock based on that cycle length.For example if the cycle length of a fast VT is 310 ms and the VT breaks during the charge, the device will look for intervals longer than 370 ms, which is 310ms plus 60ms, to determine whether the rhythm is still present.This adaptable synchronization window still allows the device to only abort shocks for rhythms which have slowed significantly but accounts for the relative change in the rate versus requiring all arrhythmias to break into a rhythm which is equal to the programmed VT zone boundary plus a buffer of 60 ms.Note that during the charge and at charge end, the device is looking for four intervals (out of five) slower than the calculated synchronization interval. If this occurs, the device aborts the shock.After charge end, the device will deliver the shock on the second arrhythmic interval (defined as an interval shorter than the calculated synchronization interval).Confirmation now available after ATP During Charging™ sequence
12 Reducing Shocks Has Been Shown to Improve ICD Patients’ QOL and Increase ICD Acceptance1,2 For some patients, anxiety related to shocks may disrupt a normal active life3,4Some studies have demonstrated that experiencing a shock may cause temporary reductions in patients’ quality of life. 5Say:As shown in clinical studies and as you may see in your practice, reducing shocks greatly improves the quality of life of ICD patientsSuggested Question for Physician:How would you feel if you could provide an ICD therapy solution to your patients that have been shown to increase their confidence and QOL?Your Objective:Highlight patient and economic benefits Protecta provides by reducing inappropriate shocks.Physician Key Take-aways:Protecta with Smart Shock technology gives patients greater confidence to actively lead their lives - Fewer Shocks. Greater Living.Protecta with Smart Shock technology reduces HC burden1 Wathen MS, et al. PainFREE Rx II Study. Circulation. 2004;110:2 Ahmad M, et al. Patients’ attitudes toward ICD shocks. PACE. June 2000;23(6):3 Sears, Todaro, Saia, Sotile & Conti .Clinical Cardiology, 22, , 1999.4 Sears SE, et al. Clin Cardiol. 2003;26:5 The Antiarrhythmics Versus Implantable Defibrillators (AVID) Investigators. A comparison of antiarrhythmic-drug therapy with implantable defibrillators in patients resuscitated from near-fatal ventriculr arrhythmias. N Engl J Med 1997; 337:
13 OptiVol® 2.0 Fluid Status Monitoring Maximise accuracy in predicting worsening heart failure.1 OptiVol detects 3 times more future events than weight monitoring alone1OptiVol 2.0 reduces unexplained detections by > 40% – more accurate identification of higher risk patients21Say:Optivol has been demonstrated to be 3 times more effective than body weight in detecting HF events.Optivol 2.0 represents an evolution in the HF tool, that reduces unexplained detections by > 40%, helping a more accurate identification of higher risk patients.1 Abraham WT, Compton S, Haas G, et al. Superior performance of intrathoracic impedance-derived fluid index versus daily weight monitoring in heart failure patients: Results of the Fluid Accumulation Status Trial (FAST). J Card Fail. November 2009;15(9):813.2 Hettrick DA, Sarkar S, Koehler J, et al. Improved algorithm to detect fluid accumulation via intrathoracic impedance monitoring in patients with implantable devices. Poster. ACC 2010.
14 It’s the Office Visit Without the Office Visit Complete Capture Management™ + Medtronic CareLink® remote monitoring system = fast and easy remote device follow-up.1Battery checkUnique threshold measurements and output adjustments (all chambers)Sensing adjustments beat-to-beatImpedance monitoringHF patient diagnostics and monitoring1 Analysis from the German TEAM-Study, 2006 Medtronic Internal Data.
15 Protecta™ XT Portfolio *Volume with connector holes unplugged. **Beginning of service. ***Recommended replacement time.
18 TWave Discrimination Operating Principles 1. Discrimination of R-waves and T-waves through differential filtering of the sensing signalDifferential filtered R-waveDifferential filtered T-wave2. Determining the R-wave and T-wave discrimination thresholdcomputeSay:This discrimination algorithm analyzes differences in amplitude, rate and pattern to differentiate R-waves from T-waves. It uses the right ventricular (RV) sensing signal (RV tip to RV ring or RV tip to RV coil) to preliminarily identify T-waves by filtering the EGM to differentiate and highlight differences in frequency content between R and T-waves. The algorithm is designed to work with both large and small R-waves.The operating principles of the feature are discussed in detail below.Discrimination of R-waves and T-waves through differential filtering of the sensing signalFirst, the sensing signal is differential filtered for 6 consecutive sensed ventricular events. Because T-waves are low frequency components, they are usually diminished in amplitude by the differential filtering process. R-waves and T-waves are then preliminarily distinguished by the size of their amplitude after the differential filtering.2. Setting the R-wave and T-wave discrimination thresholdThe maximum value of the differential signal of 2 adjacent events is measured for the 6 differential filtered ventricular events. The algorithm uses the 3 maximum values to compute the threshold.
19 TWave Discrimination Algorithm 3. Re-evaluation of R-waves and T-waves 4. Applying the discrimination criteria to R-waves and T-wavesa. R-waves (filtered EGM) meets amplitude stabilityb. T-waves (filtered EGM) meets amplitude stabilityc. R-T pair meet a interval stabilityNotes:3. Re-evaluation of R-waves and T-wavesThe 6 events are provisionally classified based on the threshold determined. Events abovethe threshold are tentatively assigned as R-waves and below are tentatively assigned as T-waves4. Applying the discrimination criteria to R and T-waves using the following criteria:The tentative R-waves must meet an amplitude stability criterion such that all tentative R-waves are of similar amplitude.The tentative T-waves must meet an amplitude stability criterion such that alltentative T-waves are of similar amplitude.The R-T pair intervals must meet an interval stability criterion such that the underlying R-R intervals are of similar length.The R/T ratio from the filtered EGM must be less than the R/T ratio on the differential EGM. Because of the filtering and differential calculations, this comparison indicates that the R-waves are of higher frequency than the T-waves.The R-T pairs must meet a pattern criterion such that the pairs must be of a pattern that would indicate alternating R and T with expected variation (no consecutive T-waves ).19
20 TWave Discrimination Algorithm Applying the discrimination critera to R-waves and T-wavesd. The R/T ratio from the filtered EGM must be less than the R/T ratio differential EGM.For example: R/T < 75%*R/T diff3 < 0.75 x 8 = 3 < 6Notes:The R/T ratio from the filtered EGM must be less than the R/T ratio differential EGM.Due to the filtering and differential calculations, this comparison indicates that the R-waves are of higher frequency than the T-waves (see Figure). Discuss example on slide.e. The R-T pairs must meet a pattern criterion that would indicate alternatingR- and T-waves.
21 TWave Discrimination Algorithm f. The “corrected” R-R interval is calculated.Notes:Once the T-waves are initially identified (by the R-wave threshold), a “corrected” R-R interval is calculated by eliminating the R-T interval. All of the R-R intervals in the 6-beat window must be slower than the programmed VT and VF detection intervals21
22 TWave Discrimination Algorithm As long as 4 of the last 20 sets meet the T-wave criteria, oversensing is detected. This means that the determination can happen after evaluating four sets as long as all identify T-wave oversensing.NotesIf all criteria are met in the set of 6 intervals, than the set is classified as T-wave oversensing and acounter is incremented by 1. If only one of the criteria is not met, then the set is classifiedas normal (no T-wave oversensing)The next group of 6 events is then evaluated using a rolling window.As long as 4 of the last 20 sets meet the T-wave criteria, oversensing is detected. Thismeans that the determination can happen after evaluating four sets as long as all identifyT-wave oversensing. [Note that a longer NID (18/24 or higher) will give the device more time to make aT-wave oversensing determination. If the NID or redetect NID is programmed to less than 12/16 thealgorithm may not have enough data to distinguish T-waves from R-waves.]NOTE: This algorithm does not affect the operation of sensing, meaning that if the T-wavesare sensed by the auto-adjusting sensitivity, they will still appear as senses in the deviceand will not suppress them. This algorithm does not eliminate T-wave oversensing. It only attempts towithhold tachy therapies for T-wave oversensing.22
23 TWave Discrimination Review Uses both signal frequency content and pattern analysis to distinguish R-T patternOnce the device senses a signal, the frequency content is used to determine whether the VS is a T-wave or an R-wave.The pattern information assures the device does not withhold for VF.Note: This algorithm does not eliminate T-wave oversensing. It only attempts to withhold shocks for T-wave oversensing.RT23
24 TWave Discrimination Programming User Programmability On, Off Nominally OnNotesT-wave Oversensing feature is user programmable ON/OFF (similar to other therapy withholding features). It is nominally ON.T-wave Discrimination is applied on initial detection and on re-detection.Note:Because the algorithm does not operate in the VT monitor zone, it does not provide notes on how the device would have worked if the zone was programmed on.The device does not use the SVT limit to determine where to apply the algorithm.T-wave oversensing Programming24
25 Diagnostics – Quick Look II TWave DiscriminationDiagnostics – Quick Look IIVOS episodes since last session Observations lists T-wave oversensing episodes25
26 Diagnostics – Episode Storage TWave DiscriminationDiagnostics – Episode Storage1. Marker Channel shows each ventricular event is counted twice. 2. TW annotated upon initial detection of T-wave oversensing. 3. TW annotated to indicate T-wave oversensing on a per-event basis.NotesThe device will store T-wave oversensing episodes (which have reached the programmed number of intervals to detect) in the V.Oversensing-T-Wave log. The episode contains the interval plot, EGM detail, episode text, and QRS snapshots. The date, time, duration, and average atrial and ventricular rates (including the T-wave oversensing) are also recorded (see figure on slide).26
27 How Does the Algorithm Work? T-wave oversensingThe algorithm is withholding the therapyAsk: How does this algorithm work?Do: Advance slide to identify T-wave oversensing and marker channel and EGM counting toward detection.Advance slide again to show continuation of T-wave Discrimination and algorithm withholding detection and therapy for T-wave oversensing.Risk of shock if detection is not withheld for T-wave oversensing!
28 RV Lead Noise Discrimination & RV Lead Integrity Alert Lead Integrity SuiteRV Lead Noise Discrimination&RV Lead Integrity Alert
29 RV Lead Noise Discrimination & RV Lead Integrity Alert Lead Integrity SuiteRV Lead Noise Discrimination&RV Lead Integrity Alert
30 RV Lead Noise Discrimination ConceptLead noise oversensing is typically isolated to the near field sensing signal The far field EGM is analyzed to determine if the event sensed on the near field EGM is noise or a true ventricular eventNotesThe RV Lead Noise Discrimination algorithm analyzes a far-field EGM signal to differentiate RV lead noise from VT/VF. If lead noise is identified when these signals are compared, VT/VF detection and therapy is withheld, and an RV Lead Noise alert is triggered.The concept behind the algorithm is that lead noise oversensing is typically isolated to the near field EGM (RVtip-RVring sense channel). Therefore, a far field electrogram signal (Can to RV coil or RVcoil to SVC) is used to validate that VT/VF senses on the near field electrogram are not present on the far field signal in the case of lead noise.30
31 RV Lead Noise Discrimination AlgorithmAmplitude is measured using far-field EGMa. Processing of the far-field EGM to determine peak-to peak amplitudeEvaluation of Amplitude (must meet two criteria)a. Average of the two smallest values is < 1mVb. Average of two smallest peak-to-peak amplitudes is <1/6 the maximum amplitudeNotesThe operating principles of the feature are:1) Amplitude is measured using a far-field EGM. Specifically, when the VT count = 2 or VF count = 3 (i.e. once a rapid ventricular rate is identified), the algorithm begins by processing the far field EGM (FF EGM) to determine the peak-to-peak amplitude in a +/- 100 ms (for a total of 200ms) window centered on either side of the corresponding ventricular sensed event (see the blue and red squares on the slide).A set of twelve (12) far-field peak-to-peak amplitudes are then evaluated.(2) Evaluation of Amplitude. After measurement of the amplitude in (1) above, the feature determines whether the 12 VT/VF events meet both of the following criteria.a. The average of the two smallest values is less than 1 mV.ANDb. There is a large difference between maximizing amplitude and baseline senses. The criterion for this difference is that the average of the two smallest peak-to-peak amplitudes is less than one-sixth the maximum amplitude.31
32 RV Lead Noise Discrimination AlgorithmThe algorithm uses a counterEach set of 12 peak-to-peak amplitudes are evaluated using a rolling windowOnce NID is reached, if 3 out of the last 12 sets are classified as noise, detection is withheldNotesTo gather sufficient evidence of lead noise before withholding detection, the algorithm is using a counter. This counter increments by one and the next set of 12 peak-to-peak amplitudes are then evaluated using a rolling window. This window functions so that a 12 beat window is reassigned on every beat (see three rolling windows in figure on slide, yellow, blue, then red respectively).Once the NID is reached, if at least 3 out of the last 12 sets are classified as noise, then the detection will be withheld. This means that the determination can happen after evaluating 3 sets as long as all are identified as Noise.New decision channel annotation: “N” indicating the feature withholds ventricular tachyarrhythmia detection.If less than 3 out of the last 12 sets are classified as noise, then the device will detect the arrhythmia in the zone that the intervals are falling within.32
33 RV Lead Noise Discrimination ProgrammingOn, On+Timeout, or OffNominal is On+Timeout for 0.75 min (45 seconds)Uses EGM2 (same as Wavelet)Nominal is Can-to-RVcoilNotesRV Lead Noise Discrimination is programmable ON/On+Timeout /OFF, provides a programmable timeout interval, and is nominally enabled with the timeout in single-chamber, dual-chamber, and CRT devices.RV Lead Noise TimeoutBecause lead noise is generally non-sustained, the RV Lead Noise Timeout is available to ensure that therapy is not withheld for long periods of time in the presence of high frequency sensing. During an uninterrupted RV lead noise event, the device withholds therapy for the duration of this interval. Should the RV lead noise event persist longer than the programmed interval, therapy will be delivered.The timeout interval ranges from 15 seconds to 2 minutes. The nominal timeout is 0.75 min (45 seconds), because 85% of lead noise episodes last less than 45 seconds. (Reference: Withholding ICD Shocks For Detected Lead Fracture Xin Zhang, Kent J Volosin, Arun Kumar, Bruce Gunderson,Jeff Gillberg. Medtronic Inc., Minneapolis, MN; . Penn Cardiology - University of Pennsylvania, Philadelphia, PA. May, 2010).Important note: to be consistent with the other timeouts available, the time is always expressed in minutes.33
34 RV Lead Noise Discrimination Alert ProgrammingUser programmable ON/OFFInterlocked with algorithmNotesThe RV Lead Noise Alert is user programmable ON/OFF. However, the audible and wireless alert are interlocked with the algorithm, which means if RV Lead Noise Discrimination algorithm is programmed OFF a interlock for the user will occur to also program RV Lead Noise Alert to OFF.34
35 Diagnostics: Quick Look II RV Lead Noise Discrimination AlertDiagnostics: Quick Look IINotesQuick Look II shows the number of episodes for which ventricular oversensing (VOS) was detected by the RV Lead Noise Discrimination feature or TWave Discrimination feature (see figure on slide). This is a NEW Episode Counter, Episode storage, and Observation diagnostic for the customer to troubleshoot episodes.NOTE: Episode counters for V.Oversensing VT/VF RX Withheld may be due to either V.Oversensing – T-wave or V.Oversensing – Noise35
36 Diagnostics: Episode Storage RV Lead Noise Discrimination AlertDiagnostics: Episode StorageNotes:V.Oversensing-Noise Episode Storage is NEW.The device will store Noise episodes (which have reached the programmed number of intervals to detect) in the V. Oversensing-Noise log. The episode contains the interval plot, EGM detail, episode text, and QRS snapshots.This new diagnostic data includes:V. Oversensing - Noise EpisodeNew decision channel annotations: “N” indicating the feature withholds ventricular tachyarrhythmia detection. “NT” is displayed when RV Lead Noise discrimination times out (see figure on slide).36
37 How Does the Algorithm Work? NoiseThe algorithm is withholding detection and therapyAsk: How does the Algorithm work?Do: Advance slide to identify noise and marker channel of fib senses counting toward detection.Advance slide again to show continuation of fib senses and algorithm withholding detection and therapy for lead noise.Risk of shock if detection is not withheld for Lead Noise!
38 RV Lead Noise Discrimination & RV Lead Integrity Alert Lead Integrity SuiteRV Lead Noise Discrimination&RV Lead Integrity Alert
39 RV Lead Integrity Alert ProgrammingUser Programmable On/OffNotesFor High Rate-NS episodes , if the log capacity has been reached and an RV Lead Integrity Alert is triggered, no new episodes will be added to the High Rate-NS log and no existing episodes will be overwritten until the device is interrogated. This allows the episodes that triggered the alert to be viewed. Overwriting of the oldest High Rate-NS episode data with new data resumes after device interrogation. High Rate-NS episodes store 5 entries (see figure on screen).39
40 RV Lead Integrity Alert DiagnosticsHigh Rate-NS episodes (New)With 1 High Rate-NS episode – the device automatically adjusts Pre-arrhythmia EGM parameter to ON – 1 monthIf Lead Impedance and SIC criteria are met, the device also changes the criteria for storing High Rate-NS episodes, allowing a High Rate-NS episode with EGM data to be recorded if a single ventricular interval < 220 occursNotesWhen at least 1 High Rate-NS episode occurs, the device automatically adjusts EGM storage operation in order to provide more diagnostic data to help identify a lead-related issue. The device programs the Pre-arrhythmia EGM parameter to On - 1 month (unless the previous setting provided more than 30 days of Pre-arrhythmia EGM storage remaining).If the Lead Impedance and Sensing Integrity Counter criteria are met, the device also changes the criteria for storing High Rate-NS episodes, allowing a High Rate-NS episode with EGM data to be recorded if a single ventricular interval less than 220 ms occurs. This condition persists until a High Rate-NS episode occurs or until the device is interrogated by a programmer.40
41 RV Lead Integrity Alert DiagnosticsAlerts and Observations for RV Lead Integrity warningNotesEvaluation of alert events:, The device stores alert events in the Medtronic CareAlert Events log. The programmer screen refers to alert events as Alert Events and OptiVol Events. For each alert event, a log entry includes the date and time of the alert, a description of the event, and the measurement or information that caused the event. Up to 15 Alert Events are stored.41
43 Improved SVT Discrimination PR Logic® + WaveletNotes:The operation of both PR Logic and Wavelet SVT discrimination features remain unchanged if programmed on independently, however minor modifications were made if programmed on sequentially to allow for the application of Wavelet in double tachycardias, and for those rhythms with V-V intervals are equal to or slower than A-A intervals to activate Wavelet.43
44 Wavelet in Dual and Triple Chamber Devices Wavelet Auto Template Collection:Excludes templates where atrial pacing occurs before a ventricular sense to avoid template corruptionAuto Template Collection shipped OFF in CRT-DManual collection recommendedWavelet EGM:EGM 2 source shipped Can to RV-coil nominally (same far-field vector used in VR devices)When PR Logic® is OFF and Wavelet is ON, Wavelet operates the same as in VR devicesNotes:Wavelet template collection: • The acquisition of a template for use by the Wavelet algorithm for SVT discrimination may present additional challenges in subjects indicated for dual-chamber and CRT-D devices because of atrioventricular conduction defects. The Wavelet template must be created from beats of supraventricular origin.Note: Auto Template Collection is shipped OFF in CRT-D devices: MANUAL collection is recommended44
45 How Does the Algorithm Work? SVTThe algorithm is withholding detection and therapyAsk: How does the Algorithm work?Do: Advance slide to identify SVT and marker channel of 1:1 with narrow QRS counting toward detection.Advance slide again to show continuation of SVT (AT) and algorithm withholding detection and therapy for Wavelet.Risk of shock if the SVT is not detected!
46 SVT Limit Nominal Change and VF High-Rate Timeout ItemConsulta®/Secura® DefinitionProtecta™ DefinitionSVT Limit Nominal320 ms(VFDI 320 ms Nominal)260 msHigh-Rate TimeoutApplies to VT and VF Zone with the same time limitNominally OFFUnchangedVF High-Rate TimeoutNot AvailableApplies only to the VF ZoneNominally ON in VR (45 seconds)Nominally OFF in DR/CRT-DVF therapy changed from ATP Before Charging® to ATP During Charging™ after timeoutNotes:Comparison chart: Consulta/Secura and Protecta46
47 PR Logic + Wavelet Programming SVT Limit change is within current programmable rangeVF High-Rate Timeout physician programmableHigh-Rate timeout that applies only to the VF zoneStill have high-rate timeout that applies to all zonesNote: VF Zone-HRTO (i.e. expiration of the timer) will result in the temporary change of a pending ATP Before Charging therapy to ATP During Charging. This change is meant to minimize any possible delay between and prior to defibrillation shock delivery.47
49 Case Study: Operation in EnTrust Confirmation +Case Study: Operation in EnTrustCurrent Confirmation Interval = TDI + 60 ms420 ms = 360 ms + 60 msNotesThe definition of an arrhythmic event is determined in the existing algorithms by comparing ventricular intervals to a device defined Confirmation interval (CI), or sometimes referred to as Arrhythmic Window.Intervals that are less than (faster than) the Confirmation interval are classified as arrhythmic.In current devices the Confirmation interval is defined as the longest programmed detection interval enabled +60ms. (TDI+60 or FDI+60 if VT detection is off).TDI + 60ms: 360ms + 60ms = 420ms. Confirmation begins after the Charge End in EnTrust device. Note (building arrows on slide) two intervals < TDI + 60ms are confirmed and a shock is delivered.ReconfirmSyncShock49
50 Case Study: Operation in Protecta Confirmation +Case Study: Operation in ProtectaAbortNotesConfirmation+ uses the same basic algorithm and incorporates a similar 60 ms change to define that the rhythm has slowed. However, the 60ms difference is relative to the intrinsic rate at the point of detection. Additional criteria may be applied depending on the zone of detection and whether the rhythm is polymorphic:1. If the rhythm is detected in the VF Zone and is polymorphic, the Confirmation Interval is FDI+60ms;Otherwise (i.e. detection of in VF zone and monomorphic, in VT or in FVT), the CI is the Rhythm cycle length at the point of detection + 60ms and must be at least the programmed VF detection interval The Rhythm cycle length is calculated considering the six V-V intervals immediately prior to detection or redetection.VT zone programmed ON at 360 ms (Old CI = 420 ms)Rhythm cycle length = 250 msShock would be aborted with Protecta during chargingConfirmation Interval = 250 ms + 60 = 310ms (greater than FDI)Confirmation Interval = Rhythm Cycle length + 60 ms310 ms = 250 ms + 60 msVT zone programmed ON at 360 ms (Old CI = 420 ms)Rhythm cycle length = 250 msShock would be aborted with ProtectaConfirmation Interval = 250 ms + 60 = 310 ms Intervals after ATP During Charging used in confirmation50
51 Confirmation + Concept A stability calculation is used to classify regular and irregular:If the difference between the minimum and maximum of the intervals used for the Ventricular average is less than or equal to 50 ms, the rhythm is deemed regular.If the difference between the minimum and maximum of the intervals used for the Ventricular average is greater than 50 ms, the rhythm is deemed irregular.If Rhythm Based Confirmation Interval is in VF zone and rhythm is irregular: Confirmation interval = FDI + 60 msNotesA stability calculation is used to classify regular and irregular. This stability calculation is accomplished by evaluating the six V-V intervals immediately prior to detection or redetection (same 6 intervals used to calculate the rhythm cycle length). the minimum and maximum intervals are dropped.If the difference between the remaining minimum and maximum of the intervals used for the Ventricular average is greater than 50 ms, the rhythm is deemed irregular.If the difference between the remaining minimum and maximum of the intervals used for the Ventricular average is less than or equal to 50ms, the rhythm is deemed regular.This is applied when the rhythm cycle length is detected in the VF Zone (regardless of if the VT Zone is ON or OFF).Note: The device will allow the first defibrillation therapy to be aborted on initial detection as well as redetection . For each time, the confirmation interval will be recalculated from the rate at redetection.51
52 Confirmation + Concept These changes allow confirmation to apply to more scenarios:VF Rx1 can abort more than once per episodeConfirmation and delivery algorithm are the same independent of ATP During ChargingNotesTherefore, even when ATP During Charging is applied, the device will be able to abort the charge during the charging process (the counting of the 4 out of 5 V-V intervals will start one V-V interval after the last therapy pace )Whenever a shock is aborted, the device continues to monitor the arrhythmia. If the arrhythmia is re-detected, the decision process to shock or withhold is again applied.The device will allow the first defibrillation therapy to be aborted after initial detection as well redetection following an aborted shock. For each time, the Confirmation interval will be recalculated from the rate at redetection.These changes allow confirmation to apply to more scenarios:VF Rx1 can abort more than once per episodeConfirmation and delivery algorithm are the same independent of ATP During ChargingKey difference is the Confirmation interval determination changed from value based on programmed detection intervals to value based on detected arrhythmia cycle length.NOTE:Confirmation during redetection provides the same ability to abort a shock if the rhythm slows on the second or subsequent attempts to deliver the first VF therapy.Confirmation during charging, in combination with ATP during charging, provides the same ability to abort a shock during charging whether ATP during charging was applied or not.52
53 Confirmation + Concept Item Current Definition Protecta Definition Confirmation During RedetectionTherapy during redetection is not confirmed.If the initial therapy aborts and the device redetects, Rx1 is confirmed during redetectionRx2-Rx6 are not confirmed during redetectionConfirmation During Charging with ATP During the ChargeNot AvailableOnly intervals after charge end are considered.AvailableUses intervals following the delivery of ATP During Charging to apply to the confirmation process.NotesKey is synch interval determination changed from value based on programmed detection intervals to value based on detected arrhythmia cycle length.53
54 Confirmation + Programming Programmable ON/OFF Nominally ON No new diagnostic dataNoteIf OFF, the device reverts to the Confirmation Interval definition ofConsulta/Secura.54
55 How Does the Algorithm Work? ATP During ChargingAbortedAsk: How does the Algorithm work?Do: Advance slide to identify ATP During Charging.Advance slide again to show Confirmation+ aborted charge during charging process, even for T-wave oversensing.
57 No changes to daily impedance measurement OptiVol 2.0Algorithm ChangesChangeDescription of ChangeRationale/Benefit of Change1. Reference Slope AdjustmentReference Impedance increases faster and decreases slower for first 100 days after initializationEnhanced ability to track impedance changes, thus improve sensitivity, after reference initialization2. VariabilityAccumulate Fluid Index less in patients with higher day to day variabilityReduce amount of accumulation in patients with high variability to reduce false detection3. Finite MemoryAccumulate Fluid Index over a finite period of time (30 days)Accumulate over the recent past to make fluid index more representative of patient’s current conditionNotesThe OptiVol 2.0 algorithm is comprised of 3 algorithmic changes.1. The Reference Impedance will increase faster and decrease slower in the first 100 days after an implant. The purpose of this change is to make the device more sensitive to events during the first 100 days after an implant.2. The device will automatically adjust how much Fluid Index accumulates to account for day-to-day variation in patient’s daily impedance measurements. The purpose of this is to accumulate the Fluid Index less in patients whose daily impedance varies a lot from day to day.3. The Fluid Index in OptiVol 2.0 is a sum of the difference between the Daily Impedance and the Reference Impedance for the last 30 days of an event. This change allows the Fluid Index to show when the patient is getting better.One major point to make is that the device is still measuring the Daily Impedance in the exact same way as it did before. All changes are limited to the algorithm that calculates the Fluid Index and the Reference Impedance.No changes to daily impedance measurement57
58 Reference changes faster after initialization OptiVol 2.0Algorithm Changes: SlopeReference changes faster after initializationReference Initialization460100Reference Impedance slopes up faster and slopes down slower for first 100 days after initializationOptiVol 1.0OptiVol 2.0Daily ImpedanceFluid IndexReferenceImpedanceDays after initializationNotesThis slide shows in more detail the Reference Slope adjustment. The threshold crossing event that was missed in OptiVol 1.0 will now be detected by OptiVol 2.0 due to increases sensitivity of the algorithm 100 days after reference impedance initialization.The reference impedance is established on day 34 post implant. The daily impedance often continues to gradually increase beyond day 34 due to pocket healing. These observed clinical increases in the daily impedance often occur at rates greater than the maximum rate of increase in the OptiVol 1.0 reference impedance. Therefore the reference impedance may lag below the daily impedance resulting in lower sensitivity of the fluid index to decreases in the daily impedance. The design of the OptiVol 2.0 algorithm will allow a higher maximum rate of increased reference impedance during the first 100 days post initialization making it more sensitive during that time period.58
59 OptiVol 2.0Algorithm Changes: VariabilityAccumulate Fluid Index less aggressively in patients with higher day to day variabilitydaysImpedanceFluid Index53161901.251.00.5ThresholdVariabilityFractionAccumulationDurationOptiVol 2.0 Fluid Index is accumulation of shaded portionReferenceAttenuates accumulation of the Fluid Index based on day to day variation in daily impedance, from day 5 through 90 of the fluid index eventBehaves same as OptiVol 1.0 if the Fluid Index Event lasts longer than 90 daysNotesThe figure basically shows that as the event progresses, the Fluid Index accumulation is controlled by the variability fraction and the day-to-day variation in the Daily Impedance.59
60 OptiVol 2.0 Algorithm Changes: Finite Memory Accumulate only over last 30 daysReferenceReferenceImpedanceImpedanceOptivol 1.0Optivol 2.0FluidIndexNotesThe animation on the right shows the 30 day window (shaded) during which the fluid index is accumulated. This is a rolling window of time. It allows the Fluid Index to decrease if the patient’s Daily Impedance gets closer to the Reference Impedance (implying the patient is getting better).In Optivol 1.0 as long as there was a difference between the Daily Impedance and the Reference Impedance, the Fluid Index would continue to increase, even if the patient is getting better. In OptiVol 2.0, if the event lasts longer than 30 days and the Daily Impedance is getting closer to the Reference Impedance the Fluid Index could decrease. This behavior in the Fluid Index corresponds better to the patient’s status, the patient getting better could result in the Fluid Index going down.*Important to point out for OptiVol 2.0*- The OptiVol event begins when the Fluid Index crosses threshold for the first time and ends when the Fluid Index is 0. It is possible for the Fluid Index to go below Threshold but the event still continues as long as the Fluid Index is non-zero.FluidIndexThresholdThreshold60
61 OptiVol 2.0Case StudyASK: 1. What are your observations about OptiVol fluid crossings for OptiVol 1.0 vs 2.0? Answer: a) There were 3 crossings with OptiVol 1.0, but only 2 crossings with OptiVol 2.0. b) However, the net days above threshold is actually higher for 2.0 .ASK: 2:How would you explain the first threshold crossing to a clinician?? Answer: The focus should be on what happened to this patient in mid February. Was the patient in the hospital at this time? Something caused a sharp drop in impedance, perhaps a system modification? Both 1.0 and 2.0 are sensitive to events like this with very large changes in the fluid index.ASK: 3: How might you explain the differences between OptiVol 1.0 and 2.0 between October 2007 and February 2008? Answer: OptiVol 1.0 rises above 200 ohnm days and stays there for In contrast, the rise is slightly more gradual (due to the variability modification) and the fluid plateaus and actually decreases as the daily impedance is actually increasing in October. Note also that OptiVol 2.0 takes a few more days to achieve threshold for OptiVol 2.0 in this event.ASK: 4: Without having the full Cardiac Compass and patient history for this case, what other questions would you want to ask to gather more information about this patient to interpret the rising and falling of the thoracic impendence? Answer: a) what was the case timeline for this patient? (major milestones), b) c) what therapy adjustments have been made? i.e. What happened to this patient in Mid –February What changed for this patient in early August Was there a drug change near this date?What do you notice about the Daily Impedance? Answer: OptiVol 2.0 does not affect the Daily impedance.
62 Differences in Behavior to the User OptiVol® 1.0/1.1OptiVol 2.0Fluid IndexCan increase or reset to 0Can increase, remain the same, decrease, or reset to 0ThresholdReprogramming threshold to a value higher than the fluid index terminates the OptiVol eventReprogramming threshold during an OptiVol event has no effect on current eventAdjust Reference ImpedanceCannot reset the Reference impedanceAvailable to reset the Reference impedanceNotes:Although your customer may not want the details of these changes that we just discussed, there are three behavioral differences that they may want to note. Thus, it is important for you to understand these key changes in OptiVol between 1.0/1.1 to 2.0.-FLUID INDEX: Due to the finite Fluid Index accumulation, the Fluid Index can decrease in OptiVol This will indicate that the Daily Impedance is getting closer to the Reference Impedance and the patient is getting dryer.-Threshold: Reprogramming threshold during an OptiVol event has no effect on current event. Threshold should not be reprogrammed while the patient is in an OptiVol alert event. This will have no impact on the duration of the event or the alerts. If the Threshold needs to be reprogrammed that should be done when the patient is not in an OptiVol alert event.-Adjusting Reference Impedance: Adjust Reference Impedance allows you to reset the Reference Impedance. This should be used only when the patient is stable and not in an OptiVol event. This feature helps re-establish a new threshold after surgical procedures. Use caution when adjusting the reference impedance.In the end, these changes are allowing the reference impedance to more closely reflect the fluid impedance.62
63 References:1 Kadish A, Dyer A, Daubert JP, et al, for the Defibrillators in Non-Ischemic Cardiomyopathy Treatment Evaluation (DEFINITE) Investigators. Prophylactic defibrillator implantation inpatients with nonischemic dilated cardiomyopathy. N Engl J Med. May 20, 2004;350(21):2 Daubert JP, Zareba W, Cannom DS, et al, for the MADIT II Investigators. Inappropriate implantable cardioverter-defibrillator shocks in MADIT II: frequency, mechanisms, predictors,and survival impact. J Am Coll Cardiol. April 8, 2008;51(14):3 Poole JE, Johnson GW, Hellkamp AS, et al. Prognostic importance of defibrillator shocks in patients with heart failure. N Engl J Med. September 4, 2008;359(10):4 Mitka M. New study supports lifesaving benefits of implantable defibrillation devices. JAMA. July 8, 2009;302(2):5 Wathen MS, DeGroot PJ, Sweeney MO, et al, for the PainFREE Rx II Investigators. Prospective randomized multicenter trial of empirical antitachycardia pacing versus shocks forspontaneous rapid ventricular tachycardia in patients with implantable cardioverter-defibrillators: Pacing Fast Ventricular Tachycardia Reduces Shock Therapies (PainFREE Rx II) trialresults. Circulation. October 26, 2004;110(17):6 Sweeney MO, Sherfesee L, DeGroot PJ, Wathen MS, Wilkoff BL. Differences in effects of electrical therapy type for ventricular arrhythmias on mortality in implantable cardioverterdefibrillatorpatients. Heart Rhythm. March 2010;7(3):7 Virtual ICD: A Model to Evaluate Shock Reduction Strategies. Presented at HRS 2010 (P03-125).8 Protecta Clinical Study, Medtronic data on file.9 Sweeney MO, et al. Differences in effects of electrical therapy type on health care utilization in the MVP ICD Trial. HRS, 2010.
64 Brief Statement:Protecta XT CRT-D, DR, VR ICDsIndications: The Protecta XT CRT-D system is indicated for ventricular antitachycardia pacing and ventricular defibrillation for automated treatment of life-threatening ventricular arrhythmias and for the reduction of the symptoms of moderate to severe heart failure (NYHA Functional Class III or IV) in those patients who remain symptomatic despite stable, optimal medical therapy and have a left ventricular ejection fraction less than or equal to 35% and a prolonged QRS duration. Atrial rhythm management features such as Atrial Rate Stabilization (ARS), Atrial Preference Pacing (APP), and Post Mode Switch Overdrive pacing (PMOP) are indicated for the suppression of atrial tachyarrhythmias in ICD-indicated patients with atrial septal lead placement and an ICD indication.The Protecta DR and VR system is indicated to provide ventricular antitachycardia pacing and ventricular defibrillation for automated treatment of life-threatening ventricular arrhythmias in patients with NYHA functional class II/III heart failure. The Protecta DR is also is indicated for use in the above patients with atrial tachyarrhythmias, or those patients who are at significant risk of developing atrial tachyarrhythmias. Atrial rhythm management features such as Atrial Rate Stabilization (ARS), Atrial Preference Pacing (APP), and Post Mode Switch Overdrive pacing (PMOP) are indicated for the suppression of atrial tachyarrhythmias in ICD-indicated patients with atrial septal lead placement and an ICD indication.Additional Protecta XT DR System Notes: ● The ICD features of the device function the same as other approved Medtronic market-released ICDs. ● Due to the addition of the OptiVol diagnostic feature, the device indications are limited to the NYHA functional class II/III heart failure patients who are indicated for an ICD. ● The clinical value of the OptiVol fluid monitoring diagnostic feature has not been assessed in those patients who do not have fluid retention related symptoms due to heart failure. ● The use of the device has not been demonstrated to decrease the morbidity related to atrial tachyarrhythmias. ● The effectiveness of high-frequency burst pacing (atrial 50 Hz Burst therapy) in terminating device classified atrial tachycardia (AT) was found to be 17%, and in terminating device classified atrial fibrillation (AF) was found to be 16.8%, in the VT/AT patient population studied. ● The effectiveness of high-frequency burst pacing (atrial 50 Hz Burst therapy) in terminating device classified atrial tachycardia (AT) was found to be 11.7%, and in terminating device classified atrial fibrillation (AF) was found to 18.2% in the AF-only patient population studied.Additional Protecta XT VR System Notes: ● The ICD features of the device function the same as other approved Medtronic market-released ICDs. ● Due to the addition of the OptiVol diagnostic feature, the device indications are limited to the NYHA functional class II/III heart failure patients who are indicated for an ICD. ● The clinical value of the OptiVol fluid monitoring diagnostic feature has not been assessed in those patients who do not have fluid retention related symptoms due to heart failure.Contraindications: The Protecta XT CRT-D, DR and VR system is contraindicated for patients experiencing tachyarrhythmias with transient or reversible causes including, but not limited to, the following: acute myocardial infarction, drug intoxication, drowning, electric shock, electrolyte imbalance, hypoxia, or sepsis. The device is contraindicated for patients who have a unipolar pacemaker implanted. The device is contraindicated for patients with incessant VT or VF.Contraindications specific to Protecta XT CRT-D and DR: The device is contraindicated for patients whose primary disorder is chronic atrial tachyarrhythmia with no concomitant VT or VF.Contraindications specific to Protecta XT VR: The device is contraindicated for patients whose primary disorder is atrial tachyarrhythmia.Warnings and Precautions: Changes in a patient’s disease and/or medications may alter the efficacy of the device’s programmed parameters. Patients should avoid sources of magnetic and electromagnetic radiation to avoid possible underdetection, inappropriate sensing and/or therapy delivery, tissue damage, induction of an arrhythmia, device electrical reset or device damage. Do not place transthoracic defibrillation paddles directly over the device. Additionally, for CRT-ICDs, certain programming and device operations may not provide cardiac resynchronization.Potential Complications: Potential complications include, but are not limited to, rejection phenomena, erosion through the skin, muscle or nerve stimulation, oversensing, failure to detect and/or terminate tachyarrhythmia episodes, acceleration of ventricular tachycardia, and surgical complications such as hematoma, infection, inflammation, and thrombosis.See the device manual for detailed information regarding the implant procedure, indications, contraindications, warnings, precautions, and potential complications/adverse events. For further information, please call Medtronic at and/or consult Medtronic’s website atCaution: Federal law (USA) restricts these devices to sale by or on the order of a physician.
Your consent to our cookies if you continue to use this website.