1. uams.edu arpediatrics.org Subcutaneous- ICD implants in a Pediatric center Srikant Das, MD Director, Electrophysiology and Pacing Arkansas Children’s Hospital

2. uams.edu arpediatrics.org Background An entirely subcutaneous ICD system (S-ICD) avoids the need for the placement of electrodes within the heart and can provide clinical advantages especially in pediatric population. Approved by the Food & Drug Administration (FDA) in 2012 Gained Category 1 CPT Codes in January 2015 Shown to be highly effective. We describe the initial experience of S-ICD implants in four children in electrophysiology laboratory in Arkansas Children’s Hospital.

3. uams.edu arpediatrics.org S-ICD TM System  Sensing Configuration  System Components 145g (78.2 X 65.5 X 15.7 mm) Emblem 130g (69.1 X 83.1 X 12.7 mm)

4. uams.edu arpediatrics.org S-ICD in children

5. uams.edu arpediatrics.org Historical ICD Challenges The ICD lead is considered the most fragile component of a transvenous ICD system. Source: Kleeman 2007

6. uams.edu arpediatrics.org Historical ICD Challenges The incidence of transvenous lead failure increases over time. Source: Kleeman 2007

7. uams.edu arpediatrics.org A New Alternative: S-ICD TM System The S-ICD TM System provides defibrillation therapy via a completely subcutaneous defibrillation system.

8. uams.edu arpediatrics.org Clinical Benefits Because the heart and vasculature remain untouched, the S- ICD TM System reduces the risks associated with TV-ICDs

9. uams.edu arpediatrics.org Design of S-ICD The S-ICD System is comprised of the following four devices: 1. Pulse Generator – 80-J biphasic shock – Charge time to 80-J ≤ 10 seconds – 5.1 year longevity – 30 seconds post-shock pacing 2.Q-TRAK Subcutaneous Electrode 3.Q-GUIDE Electrode Insertion Tool (EIT) 4.Q-TECH Programmer

10. uams.edu arpediatrics.org System Components In addition to the pulse generator and subcutaneous electrode, the S-ICD TM System includes an electrode insertion tool and programmer.

11. uams.edu arpediatrics.org START Study The START study showed that the S-ICD TM System is equivalent to a TV-ICD in sensitivity and superior to a TV-ICD in specificity Source: Gold 2011

12. uams.edu arpediatrics.org Registry Results The complication free rate was 94% at 180 days Source: Lambiase 2014

13. uams.edu arpediatrics.org Danish TV-ICD Registry Results Complication rates: Danish TV-ICD and EFFORTLESS S-ICD registry results

14. uams.edu arpediatrics.org Patient Screening  ECG Screening Tool  ECG Screening Configuration  QRS Evaluation  Lead Acceptability

15. uams.edu arpediatrics.org Optimal Sensing Configuration The optimal S-ICD TM System sensing configuration is a parasternal electrode and left lateral pulse generator. Source: Bardy 2001-2004

16. uams.edu arpediatrics.org ECG Screening Tool Pre-implant screening ensures the patient is a good candidate for S-ICD TM System implant and subcutaneous defibrillation therapy.

17. uams.edu arpediatrics.org ECG Screening Configuration Adjust the gain as needed to ensure the peak of each R wave is completely visible…. not clipped as shown here. CRM-151903-AC FEB 2015

18. uams.edu arpediatrics.org ECG Screening Configuration Use a three-lead configuration that represents the intended location of the implanted pulse generator and subcutaneous electrodes.

19. uams.edu arpediatrics.org Sensing Configuration The pulse generator is implanted at the mid-axillary line. The proximal sensing ring is placed near the xiphoid, and the distal sensing ring in the superior sternum.

20. uams.edu arpediatrics.org Sensing Vectors The S-ICD TM System uses three sensing vectors to interpret subcutaneous ECG signals.

21. uams.edu arpediatrics.org QRS Evaluation Select the color profile that best matches the QRS complexes on the ECG strip. Align left edge of color profile to QRS onset.

22. uams.edu arpediatrics.org QRS Evaluation Ensure the entire QRS complex and T wave fit within the color profile.

23. uams.edu arpediatrics.org Lead Acceptability A patient is considered suitable for an S-ICD ® System implant if at least one ECG lead is acceptable for each tested posture.

24. uams.edu arpediatrics.org S-ICD TM System Implant  X-ray Landmarks  Patient Preparation  Initial Incisions  Electrode Placement  Pulse Generator Placement  X-ray Assessment

25. uams.edu arpediatrics.org X-Ray Landmarks In the AP view, the sensing rings are parallel and about 1 cm from the sternal midline. The pulse generator is at the mid-axillary line.

26. uams.edu arpediatrics.org X-Ray Landmarks In the left lateral view, the sensing rings appear to lie on the sternal surface. The pulse generator is at the mid-axillary line, in a position that is neither too anterior or too posterior.

27. uams.edu arpediatrics.org Implantation Procedure

28. uams.edu arpediatrics.org Patient Preparation Refer to landmarks to mark incision sites and the sternal midline.

29. uams.edu arpediatrics.org Patient Preparation Drape to expose the incision sites and sternal midline.

30. uams.edu arpediatrics.org Initial Incisions Ensure the pulse generator pocket is below adipose tissue and deep enough to accommodate the pulse generator.

31. uams.edu arpediatrics.org Initial Incisions Make a 2 to 3 cm horizontal incision just left and 1 cm above of the xiphoid midline. Place two sutures, spaced to match the grooves of the suture sleeve.

32. uams.edu arpediatrics.org Proximal Electrode Placement Tie distal electrode tip to EIT. Place suture sleeve on electrode body, 1 cm from proximal sensing ring.

33. uams.edu arpediatrics.org Distal Electrode Placement Use distal electrode to identify and mark superior incision site. Tunnel along sternum from xiphoid to superior incision. Pull suture with attached distal electrode through tunnel.

34. uams.edu arpediatrics.org Pulse Generator Placement Use suture to anchor pulse generator in pocket and secure the electrode at the xiphoid and superior incisions. Keep sutures loose enough to allow for range of motion.

35. uams.edu arpediatrics.org Pulse Generator Placement Confirm the electrode connector pin is inserted halfway into pin receptacle. Gently tug electrode to confirm the connection is secure.

36. uams.edu arpediatrics.org Post implant in patient # 4

37. uams.edu arpediatrics.org Age (y)DiagnosisScreenDFTDeviceProcedureFollow up 1.15,FIdiopathic ventricular fibrillation; s/p cardiac arrest Leads I,II,III 65 JS-ICD 145g (78.2 X 65.5 X 15.7 mm) 3 incisions 92 min 9 mo 2.17,MHeart transplant with ischemic cardiomyopathy and LVEF < 30% Leads I,II,III 65 JS-ICD 145g (78.2 X 65.5 X 15.7 mm) 3 incisions 112 min 9 mo 3.16,FHypertrophic cardiomyophy s/p transvenos ICD; inappropriate shocks and lead failure Leads II,III 65 JS-ICD Emblem 130g (69.1 X 83.1 X 12.7 mm) 2 incisions 120 min 3 mo 4.16,Fs/p sudden cardiac arrest; idiopathic ventricular fibrillation Leads I,II,III 65 JS-ICD Emblem 130g (69.1 X 83.1 X 12.7 mm) 2 incisions 80 min 3 mo

38. uams.edu arpediatrics.org Induction Testing  Induction Setup  Induction Progress  Time to Therapy Evaluation

39. uams.edu arpediatrics.org Time to Therapy Evaluation Evaluate the time to therapy using an external ECG strip.

40. uams.edu arpediatrics.org Appropriate vs Inappropriate Shocks Dual-zone programming enhances AF/SVT vs VT/VF discrimination to determine the appropriateness of shock therapy. Source: Weiss 2013

41. uams.edu arpediatrics.org Rhythm Discrimination The S-ICD TM System analyzes static morphology, dynamic morphology, and QRS width to classify the subcutaneous ECG signal in the Conditional zone.

42. uams.edu arpediatrics.org Algorithm Architecture Summary

43. uams.edu arpediatrics.org Advantages Advantages: Eliminates potential for infection and damage to venous system May be implanted using anatomical landmarks without fluoroscopy Potential for less inappropriate shocks in children

44. uams.edu arpediatrics.org Disadvantages: Size – Twice that of current T-ICD Battery life – 5 to 6 years as opposed to >8-10 with TV-ICD Does not provide anti-tachycardia pacing (ATP) or bradycardia pacing

45. uams.edu arpediatrics.org X-ray Assessment Optimal device placement

46. uams.edu arpediatrics.org Reimbursement Currently, the S-ICD System is covered nationally by Medicare, Aetna, Cigna and others, and regionally by numerous private and Medicaid plans.

47. uams.edu arpediatrics.org Conclusion The S-ICD system represents a viable alternative to conventional TV-ICD therapy in patients at risk of death from VT/VF Low rate of major complications thus far in clinical studies Young patients could benefit the most from this system. The implantation can be safely performed in catheterization laboratory in children.