Based on IDE study of 330 patients for 180 days FDA approves S-ICD. However S-ICD is not shown non-inferior to currently available T-ICDs. The major limitation it of S-ICD is it gives 80J shock (T-ICD less than 40J shock) and does not have anti tachycardia and bradycardia pacing capability.
The S-ICD consists of pulse generator, which is implanted near the left mid-axillary line in subcutaneous plane, and a subcutaneous lead, consisting of sensing electrodes and a shocking coil, which is tunneled 1 to 2 cm to the left of the mid-sternal line.
|Subcutaneous Implantable Cardioverter-Defibrillator
The proposed indication for an S-ICD is who do not have symptomatic bradycardia or spontaneous, recurring ventricular tachycardia (VT) that is reliably terminated with anti-tachycardia pacing (ATP)
It has been shown conclusively both appropriate and inappropriate shocks reduce quality of life and life expectancy. Anti tachycardia and bradycardia pacing capability was considered major breakthrough in ICD technology
It has been found difficult in patients of ICDs, to predict the possibility of VT and symptomatic bradycardia even after electrophysiological testing, so S-ICD place under these situations seems to be difficult is big question.
In young people with hereditary arrhythmia chances of trance venous lead displacement are high for T-ICDs and growing children may need to replace leads, it appears that S-ICD may be considered under such circumstances.