Assessing the accuracy of surface ECG as a surrogate for the sensing vectors of the subcutaneous ICD

The subcutaneous implantable cardioverter defibrillator (S-ICD) consists of a pulse generator (can) and a single subcutaneous lead with two sensing electrodes; proximal (P) and distal (D). The S-ICD records three sensing vectors; primary (P to can), secondary (D to can) and alternate (D to P). Accurate positioning of electrocardiogram (ECG) electrodes allows a surface ECG to be recorded which mimics the S-ICD sensing vectors. This technique is currently used in S-ICD screening and has potential research applications, although its accuracy has not previously been assessed