To the Editor- Strategy for revision of subcutaneous implantable cardioverter-defibrillator following inappropriate shock.

Do and colleagues reported revision of a subcutaneous implantable cardioverter-defibrillator (S-ICD) in an adult with congenital heart disease. Right-sided, substernal electrode placement was selected, previously addressing high defibrillation requirements.

Our practice excludes patients from S-ICD implantation without 2 appropriate sensing vectors. The radiograph presented does not indicate optimal positioning for either sensing or shocking. A more dorsal and caudal position of the pulse generator, intermuscularly between serratus anterior and latisimus dorsi, is less invasive and provides a secure pulse generator position with good cosmesis. A right parasternal subcutaneous placement would be sufficient for both sensing and defibrillation.

Recent publications6, 7, 8 with substernal electrodes have shown that caution is required with the surgical technique. It must be remembered that if an infection occurs with such a procedure, a life-threatening mediastinitis may ensue.

Substernal placement of electrodes for implantable defibrillation is high risk, especially after a median sternotomy. The distal tip of the electrode was manipulated through an intercostal space for fixation and was in an unusual, flexed position. The authors should have taken their own advice and attempted the least invasive methods in the first instance, rather than commencing with the most invasive and least tried method.