Subcutaneous Implantable Cardioverter Defibrillator (ICD)
Overview: A subcutaneous ICD (S-ICD) is a type of ICD that is implanted under the skin below the armpit, and can provide shocks to stop, or in some cases prevent, certain dangerous arrhythmias.
A subcutaneous ICD (S-ICD) is a new type of ICD that is implanted under the skin at the side of the chest below the armpit. It is designed to prevent sudden cardiac arrest. For many people it is an alternative to a transvenous ICD. An S-ICD is used to treat patients who are at risk for two dangerous arrhythmias, ventricular tachycardia (VT) and ventricular fibrillation (VF). The S-ICD constantly monitors the heartbeat and delivers an automatic shock when it detects the onset of VT or VF. A study published in 2020 compared the risk of inappropriate shocks and other complications from S-ICDs and transvenous ICDs and found that S-ICDs were "non-inferior" for those patients without a need for pacing.
The S-ICD's electric pulse generator (located below the armpit) is attached to an electrode that runs along your breastbone. The electrode rests near, not in, the heart. It senses irregular rhythms and can deliver therapy in the form of a shock.
Kaya, E., Rassaf, T., & Wakili, R. (2019, September 24). Subcutaneous ICD: Current standards and future perspective. PubMed Central. 10.1016/j.ijcha.2019.100409