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Subcutaneous Implantable Defibrillator


The EMBLEM MRI S-ICD System uses INSIGHT technology to identify and classify a heart rhythm, rather than individual beats. This highly sophisticated technology helps effectively sense, discriminate and convert VT/VF through a three-phase process.


The Subcutaneous Signal

The EMBLEM MRI S-ICD System uses a revolutionary approach to sensing that’s different than transvenous ICDs (TV-ICD). Far-field sensing allows the S-ICD system to capture a high-definition, morphologically rich signal, similar to a surface ECG. RHYTHM identification for TV-ICDs uses only 8 points on the intracardiac signal, while the S-ECG signal for S-ICD has up to 41 points on every QRS complex.
EMBLEM S-ICD sensing vectors

3 Sensing Vectors for Optimal Rhythm Detection

Three sensing vectors provide different perspectives of a patient’s cardiac rhythm for optimal sensing. The EMBLEM MRI S-ICD System automatically identifies the best signal for rhythm detection.

INSIGHT Algorithm Architecture


PHASE I: Detection

The Detection phase filters the subcutaneous ECG signal and generates detections for further analysis using a variety of detection profiles. Three filters are applied to minimize cardiac oversensing: the notch filter, band pass filter and SMART pass filter.
Table showing three filters the EMBLEM MRI S-ICD System uses to help minimize cardiac oversensing.

SMART Pass Reduces Inappropriate Shocks (IAS)

The one-year IAS rates measured across S-ICD studies have decreased substantially over time due to the implementation of conditional zone programming and technology improvements to minimize T-wave oversensing, including the SMART Pass filter. The 2020 UNTOUCHED study demonstrated IAS rates for S-ICD to be half the rates for TV-ICDs as demonstrated in major studies, such as ADVANCE III and MADIT-RIT.

Bar chart comparing inappropriate shock rates (IAS) shown in several major studies for S-ICD and TV-ICD.

PHASE II: Certification

The Certification phase analyzes the detected events and certifies that they are cardiac in nature. Four separate double-detection algorithms are used to prevent oversensing and ensure an accurate heart rate.

PHASE III: Therapy Decision

During the Therapy Decision phase, the INSIGHT Algorithm discriminates between treatable and other high-rate events such as atrial fibrillation, sinus tachycardia and supraventricular tachycardia to help avoid inappropriate therapy. The Conditional and Shock Zone settings are programmable.
Diagram showing the EMBLEM MRI S-ICD System’s Conditional Shock Zone and Shock Zone.

Conditional Zone Discriminators

The EMBLEM MRI S-ICD uses the following discriminators in the Conditional Shock Zone:

Static Morphology Analysis
Identifies non-shockable rhythms, utilizing the Normal Sinus Rhythm (NSR) template.

Dynamic Morphology Analysis
Identifies shockable polymorphic rhythms by comparing each complex to the previous ones.

QRS Width Analysis
Compares the QRS width to the NSR QRS width.

Confirming Therapy is Necessary

The Therapy Decision phase incorporates multiple features to confirm therapy delivery is necessary, including SMART Charge, Charge Confirmation and Shock Confirmation. The SMART Charge feature enhances the EMBLEM MRI S-ICD System’s ability to prevent charging if non-sustained events are suspected. It also automatically extends initial detection time to allow for spontaneous termination.

SMART Charge Recognition ECG data for an untreated episode.

Therapy Delivery

The EMBLEM MRI S-ICD can deliver up to 5 shocks per episode at 80 J (delivered) and polarity is reversed for each subsequent shock in an episode. The S-ICD stores up to 128 seconds of subcutaneous ECG data per episode.

 The S-ICD system’s Adaptive Shock Polarity remembers polarity of the last successful shock and automatically selects this shock polarity for the first shock of the next episode.

When Post-Shock Pacing is necessary, the sensing vector is switched to Alternate (A B) and pacing starts. Post-Shock Pacing will continue at a rate of 50 ppm using 200 mA, for up to 30 seconds.

Anatomical illustration of the ribcage showing the EMBLEM MRI S-ICD System’s Standard Polarity Shock.

Training & Education

Explore continuing education courses, best practices modules and other training and
resources for S-ICD.


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Why S-ICD?

See how S-ICD helps protect patients at risk for sudden cardiac death
while also eliminating the risk of TV-ICD lead complications.

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Implant Procedure

Learn about advancements in the
S-ICD implant procedure, including the 2-incision and intermuscular implant techniques.

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Clinical Data

Explore clinical outcomes and
learn about the first prospective, randomized, non-inferiority clinical trial comparing S-ICD to TV-ICD.