USE OF COMPUTERIZED AUTOMATIC ALGORITHM IN STUDYING THE CIRCADIAN VARIABILITY OF THE Q-T INTERVAL DURATION BY MEANS OF THE DYNAMIC ECG.

A previously assessed algorithm was applied to automatic QT determination in long term ECG tracing of healthy subjects who were also submitted to a simultaneous EEG monitoring in a sleep laboratory in order to evaluate the QT interval behavior during different sleep stages. The RR and the QT show a statistically significant increase from phase one to four, and then a decrease in the REM phase. The QT interval corrected according to the Bazett formula proved to be limited in predicting the QT interval duration in sleep because the balance of the two limbs of the automatic nervous system have a direct influence on both QT and RR.