THE "NEW FRONTIERS" OF ARRHYTHMIAS 1998

RT-43	A new computer programme for Holter ECG (3 orthogonal leads) to evaluate dynamically the QT dispersion, as well as its correlation to RR intervals


*Antonio Conti, Antonio Michelucci, Simone Mininni, Mauro Lenuzza, Andrea A. Conti, Chiara Lazzeri, Giuseppe Petrogalli, Giuseppe Catto, Franco Franchi, Gian Franco Gensini.** Dept. of Clinical Physiopathology, Dept. of Internal Medicine and Cardiology, Dept. of Internal Medicine and Gastroenterology, University of Florence, **ELA Medical, Italy.

Introduction
	The QT dispersion (QT-D), calculated as the range of QT intervals (QTmax-QTmin), has been proposed as a simple non invasive measurement of dispersion of ventricular repolarization available from the 12 lead surface electrocardiogram¹. This index can legitimately be used to reflect inhomogeneity of ventricular recovery^2-4. Several clinical studies have furthermore demonstrated the potential usefulness of this variable as a predictor of arrhythmias¹ and for monitoring the effects of antiarrhythmic drugs, including the risk of proarrhythmia^5-7. In a previous study⁸ our group evidenced how the dynamic evaluation of QT-D, by using 3 orthogonal leads, can improve both identification of risk and control of therapy effects. In order to complete the methodological assessment of the dynamic method we analyzed the relationship between RR intervals and QT-D, considering also that previous studies^9-12 furnished contrasting results in this regard.

RT-43