Previous identification of QRS onset and offset is not essential for classifying QRS complexes in a single lead

Many cardiologists use the QRS width as one of the most decisive parameter for classifying cardiac arrhythmias but, if one is working with only one lead, it is not easy to calculate this automatically and neither accurate. The purpose of this study was to evaluate the importance of the previous calculus of QRS onset and offset in a single lead arrhythmia detector. The authors have developed 2 algorithms which classified QRS complexes, the first one finds onset and offset and calculates parameters between them and the second one opens a fixed window around the R peak and computes parameters inside this window. The performance of the authors' algorithms has been evaluated using 8 patients of the MIT BIH Arrhythmia Database. The authors divided beats into 2 groups (Normal and Ventricular) depending on their origin. After the algorithms comparison they conclude that the previous calculus of QRS onset & offset is not essential for reaching an accuracy complex's classification using morphological parameters.