Mintek LV, LV-T 2.16 Rate Fading

Stratos LV/LV-T Technical Manual 99

2.16 Rate Fading

Rate Fading is intended to prevent a sudden drop in heart rate when the Stratos CRT-Ps transition from tracking an intrinsic rhythm to pacing due to an abrupt decrease in the intrinsic rate or due to Mode Switching. This smooth drop in pacing rate is designed to prevent symptoms such as dizziness, light headedness, lack of energy and fainting spells. With Rate Fading enabled, the Stratos CRT-Ps calculate a “Backup Rate” that is always active in the background. As soon as the rate decreases, the CRT-P begins pacing at the Backup Rate. The Backup Rate corresponds to a delay of the intrinsic rate corresponding to a programmable rate increase and programmable rate decrease; these parameters determine the sensitivity of the controlled rate smoothing. After four consecutive intrinsic events (As – As), the CRT-P calculates the Target Rate for the “Backup Rate”, which is a four beat average of the intrinsic rate reduced by 10 ppm. The Target Rate cannot exceed the Maximum Fading Rate (programmed as Max Activity Rate) and cannot increase faster than the RF Rate Increase (programmable in ppm/cycle).

When the intrinsic rate drops considerably (below the Target Rate), the pacing rate drops to the Backup Rate and is then decreased gradually by the programmable Decay Rate to the Sensor Indicated Rate or Basic Rate. The Backup and Target Rates are defined in Table 23.

If an atrial tachycardia occurs suddenly, triggering a mode switch, the target rate is set to the sensor rate or basic rate. The current pacing rate in the ventricle results from the current value of the Target rate before the mode switching event.

If the pacing rate reaches the intrinsic rate during rate decay, at least four consecutive intrinsic cycles above the pacing rate are required before the pacing rate is once again adapted to the last intrinsic event. Controlled rate smoothing is thereby continued during intermittent sensed events.

The Rate Fading feature is suspended while in magnet mode and disabled at ERI and in backup mode.

Contents

Family of Cardiac Resynchronization Therapy Pacemakers CAUTION Contents Page Page 9. Elective Replacement Indication (ERI) Page Page 1. General 1.1Device Description 1.2Indications 1.3Contraindications 1.4Note to Physician 1.5Warnings and Precautions 1.5.1 Interactions with Other Medical Therapy Page 1.5.2 Storage and Sterilization 1.5.3 Lead Connection and Evaluation 1.5.4 Programming and Operation AV Hysteresis Sensing – AV Conduction Unipolar/Bipolar bipolar Page 1.5.5 Home Monitoring Page 1.5.6 Electromagnetic Interference (EMI) 1.5.7 Home and Occupational Environments 1.5.8 Cellular Phones 1.5.9 Hospital and Medical Environments 1.5.10 Device Explant and Disposal 1.6Potential Effects of the Device on Health 1.7Clinical Studies 1.7.1 Stratos LV Clinical Study – AVAIL CLS/CRT Page Clinical Inclusion Criteria Clinical Exclusion Criteria Follow-UpSchedule Clinical Endpoints Accountability of PMA Cohorts Figure Figure 1: Patient Accountability Demographics and Baseline Parameters Table Table 1: Patient Demographics at Enrollment Page Table 2: Atrial Fibrillation Demographics at Enrollment Page Table 3: Current Cardiac Medications at Enrollment Safety and Effectiveness Results Page Primary Endpoint—Complication-freeRate (Safety) Page Other Medical 13.3% Total—All 25.3% Patients and Page Page Page 46.7% 60.0% Table 7: Summary of Patient Deaths All Causes Primary Endpoint: Six Minute Walk Test & QOL (Effectiveness) Table 8: Composite of Six Minute Walk Test and QOL (Effectiveness) (N = 53) Distance Walked at Baseline Primary Effectiveness Endpoint Analysis and Conclusions Multi-sitePoolability and Gender Analysis 1.7.2 Stratos LV Clinical Study – OVID study Page Page Page Page Table 10: Summary of Complications at 6 months 3.3% Atrial Lead Related 1.1% 5.6% Page 13.5% 19.1% Observation 1.7.3AVAIL and OVID Combined Primary Endpoint-Complication-freeRate (Safety) 1.2% 1.8% 12.8% 17.7% Categtories 1.7.4Tupos LV/ATx Clinical IDE Study - OPTION CRT/ATx Page Page Page Figure 2: Patient Accountability Table 13: Patient Demographics at Pre-Enrollment N=133 N=67 value Table 14: Cardiac Medications at Pre-Enrollment Drug (N=133) (N=67) Specific CHF Medications Primary Endpoint 1: Six Minute Walk Test & QOL (Effectiveness) Table 15: Composite of Six Minute Walk Test and QOL P-value Distance ∆ in QOL Score† Secondary Endpoint Results Table 16: Six Minute Walk Distance Six-Month Table 17: Improvement in NYHA Classification at Six-Monthsfrom Baseline Page 1.7.5 Conclusions Drawn from Studies Page 2. Programmable Parameters 2.1Pacing Modes 2.1.1 Rate-adaptiveModes 2.1.2 DDD Table 18: Timing Intervals Timing Event Interval Vsp Trigger Pacing Demand Pacing Triggered pacing Page 2.1.3 DDI NOTE: 2.1.4 DVI 2.1.5 VDD 2.1.6 AAI and 2.1.7 AAI 2.1.8 AOO, VOO 2.1.9 DOO 2.1.10 VDI 2.2Biventricular Synchronization of the Stratos CRT-Ps 2.3Timing Functions 2.3.1 Basic Rate 2.3.2 Rate Hysteresis 2.3.3 Scan Hysteresis Figure 3. Scan Hysteresis NOTES: 2.3.4 Repetitive Hysteresis 2.3.5 Night Mode 2.3.6 Refractory Periods 2.3.7 Atrial PMT Protection 2.3.8 Ventricular Refractory Period 2.3.9 AV Delay 2.3.9.2AV Hysteresis 2.3.9.3AV Repetitive Hysteresis 2.3.10VES Discrimination after Atrial Sensed Events 2.3.11 Sense Compensation 2.3.12 Ventricular Blanking Period 2.3.13 Safety AV Delay 2.4Pacing and Sensing Functions 2.4.1 Pulse Amplitude and Pulse Width 2.4.2 Sensitivity 2.4.3 Lead Polarity 2.5Automatic Lead Check Lead Check 2.6Antitachycardia Functions: 2.6.1 Upper Rate and UTR Response 2.7Wenckebach 2:1 Wenckebach Behavior 2:1 Behavior 2.8Mode Switching 2.9PMT Management 2.9.1 Protection 2.9.2 PMT Detection 2.10 Adjustment of the PMT Protection Window 2.11 Atrial Upper Rate 2.12 Preventive Overdrive Pacing (Overdrive Mode) Page 2.13 AES Detection and Pacing 2.13.1 AES Detection 2.13.2 Post AES Stimulation 2.14 Parameters for Rate-AdaptivePacing 2.14.1 Rate-Adaptation 2.14.2 Sensor Gain 2.14.3 Automatic Sensor Gain 2.14.4 Sensor Threshold 2.14.5 Rate Increase 2.14.6 Maximum Activity Rate 2.14.7 Rate Decay 2.15 Sensor Stimulation 2.16 Rate Fading 2.17 Home Monitoring (Stratos LV-T) Page 2.17.1 Transmission of Information 2.17.2 Patient Device 2.17.3 Transmitting Data Table 24: System Requirements / Recommendations System Requirements Recommendations (for Optimal Usage) 2.17.4 Types of Report Transmissions 2.17.4.2 Event Report 2.17.5 Description of Transmitted Data Heart Failure Diagnostics Ventricular Rhythm Leads System Status 2.18 Statistics 2.18.1 Timing 2.18.2 Arrhythmia 2.18.3 Sensor 2.18.4 Sensing 2.19 Interrogating and/or Starting Statistics 2.20 Timing Statistics 2.20.1 Event Counter 2.20.2 Event Episodes 2.20.3 Rate Trend 2.20.4 Atrial and Ventricular Rate Histogram 2.21 Arrhythmia Statistics 2.21.1 Tachy Episode Trend 2.21.2 AF Classification 2.21.3 AES Statistics 2.21.4 VES Statistics 2.22 Sensor Statistics 2.22.1 Sensor Rate Histogram 2.22.2 Activity Report 2.22.3 Sensor Optimization 2.23 Sensing Statistics 2.24 Pacing Statistics 3. Follow-upProcedures 3.1General Considerations Page 4. Real-TimeIEGM 4.1IEGM Recordings Page 5. Battery, Pulse and Lead Data 5.1Threshold Test - Testing the Pacing Function 5.2P/R Measurement - Testing the Sensing Function 5.3Testing for Retrograde Conduction 5.4.1 Description 5.4.2 Burst Stimulation 5.4.3 Programmed Stimulation 5.4.4 Back up Pacing 5.4.5 NIPS Safety Features Page 6. Other Functions/Features 6.1Temporary Programming 6.2Patient Data Memory 6.3Safe Program Settings 6.4Magnet Effect 6.5Position Indicator 6.6Pacing When Exposed to Interference Table 27: Response to EMI MODE EMI* (A) EMI* (V) EMI* (A+V) Page 7. Product Storage and Handling 7.1Sterilization and Storage 7.2Opening the Sterile Container Page 7.3Pulse Generator Orientation 8. Lead Connection 8.1Lead Configuration 8.2Lead Connection Page Page Page Page 9. Elective Replacement Indication (ERI) Table 29: Service Cycle Definitions Abbreviation Service Definition in Table Table 30: Stratos CRT-Psbehavior after reaching ERI Magnet Mode Cycles 1-10after After Cycle Page Table 32: Remaining Expected Service time (ERI to EOS) Pacing Program Stratos LV, (months) 10. Explantation Page 11. Technical Data 11.1 Available Pacing Modes 11.2 Pulse- and Control Parameters Page Page Page Page 11.3 Diagnostic Memory Functions 11.4 Home Monitoring (Stratos LV-T) 11.5 Additional Functions 11.6 Programmers 11.7 Default Programs 11.8 Materials in Contact with Human Tissue 11.9 Electrical Data/Battery 11.10 Mechanical Data 12. Order Information Page Appendix A Known Software Anomalies