
Click on the titles to explore the indications
Bradycardia Pacing
Among patients with no pacing indication at the time of ICD implant, the development of RVP is uncommon within the first 2 years after implantation15.
No significant increased risk of pacing need until age 8015.
Occurrence of new pacing need was low in real-world S-ICD registries:
Extraction for new pacing requirement: | No. of patients |
---|---|
EFFORTLESS mid-term follow-up6 | 1 / 985 (0.1%) |
Dutch 6 year follow-up16 | 1 / 118 (0.8%) |
Austrian Registry17 | 2 / 336 (0.8%) |
Need for ATP at implant
Who needs ATP:

Contemporary programming significantly reduces therapy delivered, suggesting that given sufficient time, a majority of mVT episodes will self-terminate23, 24, 25.
Rate of appropriate shock delivery
Multiple studies have shown similar rates of appropriate shocks despite reductions in ATP delivered:
1 year rate of Appropriate Therapy


Future need for ATP
Benefit of ATP:
In studies of long detection programming, 97-98.4% of patients received no benefit from ATP23, 26.
Shocks avoided by ATP in major clinical trials
Risk of VT acceleration:
rhythm to a faster, unstable, and poorly tolerated rhythm24, 27, 28, 29.
What is the role of an ICD: SCD prevention or VT management?
Catheter ablation is recommended (ESC Class I indication)11 in patients with:
- Scar-related heart disease presenting with incessant VTs
- Ischemic heart disease and recurrent ICD shocks due to sustained VTs
Real world SICD data show very low rate of change out to TV-ICD due to need for ATP:
Extraction for new pacing requirements: | No. of patients |
---|---|
EFFORTLESS mid-term follow-up6 | 5 / 985 (0.5%) |
Austrian Registry17 | 1 / 236 (0.4%) |
“Typical” ICD Patients
ICD benefit in low EF/CHF patients
- 34% reduction in SCD risk by ICD in MADIT II population30
- 23% reduction in SCD risk by shockonly ICD at five years among (ischemic and non ischemic) CHF patients18
Proportion of low EF patients implanted with an SICD has increased over time:2, 6, 31

Risk factors:
High proportion of patients at high risk of infection among low EF/CHF patients:
- 31-33% of patients with diabetes in SCDHeFT and MADIT II18, 32
- 25% of patients with renal disfunction in CHF population18, 32
S-ICD is the preferred therapy for patients who are at high risk of infections (AHA/ACC/HRS guidelines, Class I recommendation)1.
S-ICD: Class IIa recommendation for ALL ICD indicated patients without need for pacing1, 11.
Older ICD Patients

S-ICD performs better than TV-ICD in discrimination of SVT37, 38.

Appropriate ICD therapy delivered in up to 23% of older patients (with EF>25%)39.

High Risk Patients
As many as 61% of patients may have venous stenosis following initial device implantation34.
Predictors of device infection33,34,40:
- Diabetes
- Heart Failure
- Kidney disease
- Previous device infection
