Some investigations with the computation of the QT dispersion index in the ECG-ILSA database

In the present study two aspects concerning the QT dispersion in rest 12 lead ECG have been considered: the developing of algorithms to compute the index from a limited number of leads, and its prognostic significance in three selected groups. Two indices QTD1 and QTD2 (max-min and standard deviation of the QT values) have been considered In particular the implications of the selection of different leads in the algorithms for the QT dispersion index are studied and different lead groups have been evaluated and examined. A computerized ECG database in the Italian Longitudinal Study on Aging project (ILSA, Targeted Project of the National Research Council of Italy on Aging) has been used. Three sets of patients have been selected from clinical information: healthy patients, patients with only cardiac diseases and with only hypertension. The statistical significance of the difference of QTD1 and QTD2 in the three groups and their behaviour with age have been examined.