Mode of Onset of Spontaneous Ventricular Tachyarrhythmias from Implantable Cardioverter Defibrillator Electrograms

Aim: This work investigates the correlation between the cardiac electrical activity underlying spontaneous ventricular tachyarrhythmias and their modes of onset. Signals: We analyzed 81 episodes of spontaneous ventricular tachycardia (VT) and ventricular fibrillation (VF) lasting at least 5 seconds from 17 patients. The cardiologist classified VT/VF malignancy by considering fast VT as more malignant. We study 3 modes of onset: (i) premature ventricular contraction (PVC group); (ii) PVC preceded by a short-long-short cycle (SLS group); (iii) PVC preceded by a paced beat after a previous PVC compensatory pause (PM group). In 4 patients more than one mode of VT/VF onset is present, in the other 13 patients VT/VF always started with the same mode. Mathematical methods: Cardiac electrical activity is characterized by power spectral density and correlation dimension analyses; statistical analysis is carried on using one way ANOVA in order to test significant differences among the mean values of PVC, SLS and PM