Pacemaker - Basics to Advanced Features and Monitoring. Niraj Varma MD, PhD, FRCP Cleveland Clinic

Transcription

1 Pacemaker - Basics to Advanced Features and Monitoring Niraj Varma MD, PhD, FRCP Cleveland Clinic

2 Indications

3 Indications Pacing Mode Code Selection Malfunction Battery Capture Sensing Rates or not over or under too slow/ too fast Pseudomalfunction

4 Indications Sinus Node Dysfunction Pace for sx if rate <40 bpm Idiopathic Syncope and SND at EPS Chronotropic incompetence on exercise SSS: Offset pauses, Drugs

5 NBG Code The Usual Pacing Modes Chamber(s) Paced I II III IV V Chamber(s) Sensed Response to Sensing Rate Modulation Multisite Pacing O = None O = None O = None O = None O = None A = Atrium V = Ventricle A = Atrium V = Ventricle T = Triggered I = Inhibited R = Rate modulation A = Atrium V = Ventricle D = Dual (A + V) D = Dual (A + V) D = Dual (T + I) D = Dual (A + V)

6 AAI vs DDD in Sick Sinus Syndrome

7 AAI vs DDD in Sick Sinus Syndrome These findings support the routine use of DDDR pacing

8 Indications: AV Block Pace Any symptomatic AV block Asymptomatic block if - 3 rd AV block; infra-hisian 2 nd ; any Mobitz II 2 nd AV block with rates < 40 bpm or pauses >3s Do Not Pace Asymptomatic 1 st degree Supra-His block; Wenckebach Reversible AV block drugs/ OSA/ vagal/ Lyme

9 22M without significant history presents with syncope

10 69 year Old Male

11 51 year old Male

12 Case #1 Implantation of a pacemaker AAI 66 yr Male 2. VVI 3. DDD 4. CRT 5. No implantation necessary

13 Indications Bifascicular AV block Progression is 5% at 5 yrs Do not pace unless alternating BBB, syncope of unknown cause; HV >100 ms or pacing induced infra-hisian block Neuromuscular diseases Post- MI Anterior vs Inferior Neurocardiogenic disorders Carotid sinus hypersensitivity;? Vasovagal syncope

14 Case # yr Male syncope, due to CHB DDD pacer implanted

15 Chronic AF (VVI) Sinus node dysfunction w/o history of AV block (AAI) Provides AV synchrony Pacing support in both chambers as needed

16 VVI vs DDD Compared with ventricular pacing, atrial-based pacing does not Improve survival or Reduce heart failure or cardiovascular death However, Reduces the incidence of atrial fibrillation May modestly reduce stroke Healey et al Circ 2006

17 PPM Malfunction Failure of Capture Failure of Output Oversensing Inappropriate inhibition or triggering Undersensing Failure to recognize and act on native cardiac depolarizations ( P or QRS)

18 Programming information: Loss of Capture DDD bpm; PAV: 150 ms; SAV: 120 ms; PVARP: 310 ms Perform a threshold test

19 Causes If there were changes in medications, or an MI, or the patient had renal failure, etc. If lead impedance is low If chronic lead impedance is high? If lead impedance is ok? If acute lead impedance is high? Considerations Program a higher output for an increased safety margin, as conditions are changing Suspect insulation break Suspect fracture. Could try unipolar temporarily, but this will likely require a lead replacement. Suspect dislodgement. Can try a higher output, but permanent fix will likely be repositioning. Likely a loose set screw. Need to re-open the pocket and retighten it.

20 Post Implant Day #1

21 Single Chamber Timing VVI: Vp Vp Vs Vp V Ref V-V Automatic Interval Escape Interval

22 Dual Chamber Timing AV Delay VA Interval LRL Ap Vp Ap Vp Ap Vp Minimum Rate Pacing = AV +VA Intervals

23 Pacing <Lower Rate Battery depletion Electrical reset Exposure to electromagnetic interference (EMI) e.g., electrocautery, defibrillation, causing reversion to backup mode Therapy Hysteresis, Rate drop response, Mode switching, MVP, etc. Oversensing

24 Pacing < Lower Rate

25 Oversensing Underpacing Marker channel shows intrinsic activity......though no activity is present VVI / 60 An electrical signal other than intended P or R wave is detected Tx: Change sensitivity

26 Normal Tracking 2:1 Wenckebach Rate Response Pacing > Lower Rate Abnormal PMT Oversensing and triggered pacing

27 Normal Upper Rate Behaviour Upper Rate Operation: Wenckebach (4:3 Block) As Vp As Vp As Vp AR As Vp As Vp As Vp TARP AV Delay As Vp VA Interval As Vp MTR AV PVARP AV W PVARP TARP TARP MAXIMUM TRACKING RATE

28 Normal Upper Rate Behaviour 2:1 Block 2:1 Rate = 60,000 / TARP As Vp AR As Vp AV PVARP TARP MAXIMUM TRACKING RATE AV PVARP TARP

29 PVARP TARP TARP = Post Ventricular Atrial Refractory Period = Total Atrial Refractory Period = AV Delay + PVARP 2:1 Block Rate = 60,000 / TARP Sinus Rate 2:1 Block Wenckebach 1:1 TARP MTR LRL

30 PMT- Initiation: Any Loss of AV Synchrony Atrial Undersensing/ Loss of atrial capture PVC Ex. #1 : AV Delay = 150 ms PVARP = 250 MTR = 120 bpm Retrograde Conduction = 280 ms AS 150 ms 280ms VP Cycle = = 430 ms (139 bpm) PMT Rate = 120 bpm (Limited by MTR)

31 PMT - Termination Place a magnet on the device DOO suspends sensing and the tachycardia terminates No evidence of atrial tachycardia during the asynchronous operation

32 PMT- Termination Logic behind PVARP: - PMT is tracking retrograde P-waves - To eliminate PMT, ignore retrograde P-waves occuring after ventricular events - PVARP must be programmed longer than the retrograde conduction time Auto-PVARP / PVC Response

33 Pseudomalfunctions- Rate Examples Magnet 2:1 Block Operation Pseudo- Wenckebah Operation PMT Intervention Rate Response

34 Pseudomalfunctions AV Intervals/Refractory periods Examples Ventricular Safety Pace MVP Mode Rate Adaptive AV Delay PAV delay with no activity PAV with activity

35 Case #1 Management 74 yr Male Caucasian 2015 (4 years post pacing) 1. Reposition RV lead 2. Upgrade ICD 3. Upgrade CRT P 4. Upgrade CRT D 5. No change

36 1. Selective Site RV Pacing RV High Septum RAO LAO

37 2. Selective Site RV Pacing Permanent Direct His-Bundle Pacing Deshmukh et al Circulation 2000 Deshmukh et al PACE 2004

38 2. Selective Site RV Pacing Sharma HRJ 2015 Heart Failure Hospitalizations in Patients Requiring >40% pacing

39 Post Implant Follow Up

40 JACC 2015

41

42