Differentiation of supraventricular and ventricular arrhythmias based on morphological analysis of ICD stored electrograms

Implantable cardioverter defibrillators (ICD) must discriminate between normal sinus rhythm and abnormal arrhythmias, but they must also confront the problem of identifying different arrhythmias such as ventricular tachycardias (VT), ventricular fibrillation (VF) and supraventricular tachycardias (SVT). Rate is yet the main used parameter to distinguish a rhythm from another one but it is often nor successful. The authors propose an algorithm based on the electrogram morphology to discriminate among these rhythms. It uses two different coefficients calculated with CWA, BAM, NAD, DAM and ADIOS with two templates. The evaluation of the algorithm was performed on electrograms (EGM) saved by ICDs during clinical episodes that fulfilled programmed rate criteria. The authors studied from a total of 31 patients with 36 different VTs, 33 VFs and 9 different SVTs.