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

uams.eduarpediatrics.org

Subcutaneous- ICD implants in a Pediatric center

Srikant Das, MDDirector, Electrophysiology and Pacing

Arkansas Children’s Hospital


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.


S-ICDTM 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)


S-ICD in children


Historical ICD Challenges

The ICD lead is considered the most fragile component of a transvenous ICD system. Source: Kleeman 2007


Historical ICD Challenges

The incidence of transvenous lead failure increases over time.Source: Kleeman 2007


A New Alternative: S-ICDTM System

The S-ICDTM System provides defibrillation therapy via a completely subcutaneous defibrillation system.


Clinical Benefits

Because the heart and vasculature remain untouched, the S-ICDTM System reduces the risks associated with TV-ICDs


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 Electrode3.Q-GUIDE Electrode Insertion Tool (EIT)4.Q-TECH Programmer


System Components

In addition to the pulse generator and subcutaneous electrode, the S-ICDTM System includes an electrode insertion tool and programmer.


START Study

The START study showed that the S-ICDTM System is equivalent to a TV-ICD in sensitivity and superior to a TV-ICD in specificitySource: Gold 2011


Registry Results

The complication free rate was 94% at 180 days Source: Lambiase 2014


Danish TV-ICD Registry Results

Complication rates: Danish TV-ICD and EFFORTLESS S-ICD registry results


Patient Screening

ECG Screening Tool

ECG Screening Configuration

QRS Evaluation

Lead Acceptability


Optimal Sensing Configuration

The optimal S-ICDTM System sensing configuration is a parasternal electrode and left lateral pulse generator. Source: Bardy 2001-2004


ECG Screening Tool

Pre-implant screening ensures the patient is a good candidate for S-ICDTM System implant and subcutaneous defibrillation therapy.



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



Use a three-lead configuration that represents the intended location of the implanted pulse generator and subcutaneous electrodes.


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.


Sensing Vectors

The S-ICDTM System uses three sensing vectors to interpret subcutaneous ECG signals.


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.


QRS Evaluation

Ensure the entire QRS complex and T wave fit within the color profile.


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.


S-ICDTM System Implant X-ray Landmarks

Patient Preparation

Initial Incisions

Electrode Placement

Pulse Generator Placement

X-ray Assessment


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.


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.


Implantation Procedure


Patient Preparation

Refer to landmarks to mark incision sites and the sternal midline.


Patient Preparation

Drape to expose the incision sites and sternal midline.


Initial Incisions

Ensure the pulse generator pocket is below adipose tissue and deep enough to accommodate the pulse generator.


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.


Proximal Electrode Placement

Tie distal electrode tip to EIT. Place suture sleeve on electrode body, 1 cm from proximal sensing ring.


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.



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.



Confirm the electrode connector pin is inserted halfway into pin receptacle. Gently tug electrode to confirm the connection is secure.


Post implant in patient # 4


Age (y) Diagnosis Screen DFT Device Procedure Followup

1. 15,F Idiopathic ventricular fibrillation; s/p cardiac arrest

Leads I,II,III

65 J S-ICD 145g (78.2 X 65.5 X 15.7 mm)

3 incisions92 min

9 mo

2. 17,M Heart transplant with ischemic cardiomyopathy and LVEF < 30%

Leads I,II,III

65 J S-ICD 145g (78.2 X 65.5 X 15.7 mm)

3 incisions112 min

9 mo

3. 16,F Hypertrophic cardiomyophy s/p transvenos ICD; inappropriate shocks and lead failure

Leads II,III

65 J S-ICD Emblem 130g (69.1 X 83.1 X 12.7 mm)

2 incisions120 min

3 mo

4. 16,F s/p sudden cardiac arrest; idiopathic ventricular fibrillation

Leads I,II,III

65 J S-ICD Emblem 130g (69.1 X 83.1 X 12.7 mm)

2 incisions 80 min

3 mo


Induction Testing Induction Setup

Induction Progress

Time to Therapy Evaluation


Time to Therapy Evaluation

Evaluate the time to therapy using an external ECG strip.


Appropriate vs Inappropriate Shocks

Dual-zone programming enhances AF/SVT vs VT/VF discrimination to determine the appropriateness of shock therapy. Source: Weiss 2013


Rhythm Discrimination

The S-ICDTM System analyzes static morphology, dynamic morphology, and QRS width to classify the subcutaneous ECG signal in the Conditional zone.


Algorithm Architecture Summary


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


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


X-ray Assessment

Optimal device placement


Reimbursement

• Currently, the S-ICD System is covered nationally by Medicare, Aetna, Cigna and others, and regionally by numerous private and Medicaid plans.


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.

Documents

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