Implantable cardiac defibrilators

1. Implantable cardiac defibrilators DrAmirhosseinAzhari Electrophysiologist

3. ICD Leads – Single versus Dual coil

4. ICD Leads – DF-1/IS-1 versus DF4 DF-1 / IS-1 DF4

5. ICD Leads – Active versus Passive Fixation Passive fixation Active fixation

6. 2000 • ICDs with Cardiac Resynch* 1997/8 2002 • Dual-Chamber ICDs • Size Reduction • AVID • CASH • CIDS • MADIT-II 1989 1980 • Transvenous Leads • Biphasic Waveform • First Human Implant 1985 • FDA Approval of ICDs 1993 1999 • Smaller Devices • AT Therapies • MUSTT 1988 1996 • Tiered Therapy • MADIT • Steroid-eluting Leads • Increased Diagnostic and Memory Capacity Number of Worldwide ICD Implants Per Year(Ref: Corporate Market Share Database) Evolution of ICD Therapy: 1980 to Present *Currently approved for use OUS only

7. ICD History The original AID device had two electrodes, one a spring was placed in the Vena Cava, the other a cup designed to conform to the cardiac apex 1980

8. 209 cc 80 cc 113 cc 80 cc 72 cc 54 cc 39.5 cc 36 cc 62 cc 49 cc 39.5 cc 39.5 cc 39 cc 39 cc Medtronic Implantable Defibrillators (1989-2001)

9. Defibrillation Threshold - DFT • DFT is the lowest shock energy at which Ventricular Fibrillation (VF) is reliably converted into sinus rhythm • The electrical dosage is often expressed in energy (Joules) • The electrical dosage can also be expressed in voltage (Volts) • DFT can be measured during the ICD implant • Commonly a standard energy safety margin of 10 J is applied above the DFT energy after 2 successful VF conversions

10. Delivered and Stored Energy • The stored energy is the maximal energy that can be stored in the capacitor (it is a not very important value) • The delivered energy is the energy the device can realistically deliver to the patient • In comparing devices it is very important to know about which energy you are talking

11. Shocking Vector • Enables selection of RV defibrillation polarity relative to the “can” and /or SVC electrode for the first phase of biphasic waveform. • Polarity can be changed non-invasively. • RV polarity: Anode (+), Cathode (-) • To increase defibrillation efficacy

12. Cathode (-) Cathode (-) Anode (+) Shocking vector: Default Polarity

13. Cathode (-) Anode (+) Cathode (-) Anode (+) Anode (+) Cathode (-) Shocking vector: Reversed Polarity

14. Rate Branch Classification – DR and BiV ICDs • Atrial and Ventricular rates are measured • Classifies the rhythm into one of three branches according to the relationship between the Atrial and Ventricular Rate • VT / VF Rate Branch (V rate > A rate) • Sinus Rate Branch (V rate similar to A rate) • AF / AFlut Rate Branch (V rate < A rate)

15. Zone Configuration

16. Detection VF Detection ! VF Therapy !! F F F F F F F F F F

17. Fib Zone 1 2 3 4 5 6 7 8 9 10 11 12 Initiate Therapy Detect Analyse Charge Detection

18. 310 340 300 290 330 320 300 310 Rate Branch Calculation - Example VT Detection: 8 intervals < 350 ms VT Detect 290 300 300 330 340 320 310 310 Median Ventricular Cycle Length = (310 + 310) / 2 = 310 ms

19. ICD Therapies - ATP

20. ATP Definition • ATP = Antitachycardia Pacing • ATP = Therapeutic intervention using standard bradycardia pacing algorithms and energy levels in an effort to bring the heart out of a reentrant tachycardia and restore its normal rhythm

21. VT based on reentry

22. 1 sec VT

23. Proparly Timed Electrical Stimulation

24. ATP

25. 1 sec ATP ATP arrhythmia Sinus rhythm

26. Electromagnetic Interference andImplantable Devices

27. It is important to know not only what sources of interference are of potential concern, but also how external interference actually affects pacemakers, implantable cardioverter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT) systems.

29. Electromagnetic fields have both an electric field, measured in volts per meter (V/m), and a magnetic field. The magnetic flux density is measured in milliteslas (mT).

31. Pacemaker and ICD Responses to Electromagnetic Interference

32. The most frequent responses : • Inappropriate inhibition • triggering of pacemaker stimuli • reversion to asynchronous pacing • ICD tachyarrhythmia detection. much less frequent: • Reprogramming of operating parameters • Permanent damage to the device circuitry • Electrode-tissue interface

33. Sources of Electromagnetic Interference in Daily Life

34. Cellular Telephones and Other WirelessCommunication Devices • Although isolated case reports have suggested the potential for severe interactions, most research indicates that deleterious interactions are unlikely to happen with normal cellphone use. • There was no clinically significant EMI episodes when the telephone was placed in the normal position over the ear..

35. Maintaining an activated cellphone at least 6 inches (15 cm) from the device prevents interactions. • The FDA has issued simple recommendations to minimize the risks: • Patients should avoid carrying their activated cellphone in a breast or shirt pocket overlying an implanted device. • A wireless telephone in use should be held to the ear opposite the side where the device is implanted.

36. Gates • No spurious detections occurred during a 10- to 15-second walk through the gates. All of the patients with serious interactions had an abdominal implant; however, by multivariate analysis, diminished R-wave amplitude and a Ventritex ICD were the only predictors of interactions.

37. Metal Detectors • Handheld metal detectors typically operate at a frequency of 10 to 100 kHz. • one report of a spurious ICD shock triggered by a handheld metal detector in an airport. • Guidant ICDs reverted to “monitor-only” mode after being exposed to metal detectors.

38. Current FDA recommendations state that it is safe for patients with implanted cardiac devices to walk through a metal detector gate, although the alarm may be triggered by the generator case. • If scanning with a handheld metal detector is needed, patients should ask the security personnel not to hold the detector close to the implanted device longer than is absolutely necessary. • A manual personal search can also be requested

39. Direct Current Cardioversionand Defibrillation The risk of damage to the implanted device depends: • on the amount of energy applied • the characteristics of the device and lead, • and the distance between the paddles or pads and the pulse generator and leads

41. Operation with electrocutering surgery

43. Incidence of complications was low (0.8 cases per 100 years of surgical practice).

46. ICD and CRT guidelines2013primary prevention

47. Scoring • The technical panel scored each indication • Score 7 to 9: Appropriate option procedure is generally acceptable and is generally reasonable for the indication • Score 4 to 6: May Be Appropriate care procedure may be acceptable and may be reasonable for the indication • Score 1 to 3: Rarely Appropriate care

48. A 42 years old man with Ant MI 20 days ago primary PCI (+) Now EF=30-35 • Episodes of NSVT • No evidence of ischemia

49. A)EPS • B)Wait 40 days • C)Antiarrhytmic • D)ICD

50. EPS VT induced ????