Characterizing atypical patterns of Heart Rate before Paroxysmal Ventricular Tachycardia.

Results of a comparative analysis between Heart Rate (HR) patterns occurring before the onset of Paroxysmal Ventricular Tachycardia (PVT) and from healthy subjects are shown. Two study groups were made after electrocardiographic dynamical monitoring (Holter) of volunteers. The first group includes 100h from 27 healthy control subjects, and the second group consists of 88h, ending with self-terminating episodes of PVT from 55 patients. Patterns are defined as sequences of consecutive RR intervals, while atypical patterns are defined as corresponding to unlikely behavior of Heart Rate in healthy subjects. We investigated spatial and temporal distributions of these patterns in order to find early signs of PVT. We found that they can be grouped on a reduced number of clusters, and the number of atypical patterns increases as we approach the onset of the episode.