Method and system for evaluating arrhythmia risk with QT-RR interval data sets

摘要

A method of assessing the cardiac arrhythmia risk in a subject to provide a measure of cardiac or cardiovascular health in that subject is described herein. In one embodiment, the method comprises the steps of: (a) collecting at least one QT and RR interval data set from the subject during (i) a stage of gradually increasing or constant heart rate, (ii) a stage of gradually decreasing or constant heart rate, or (iii) both a stage of gradually increasing or constant heart rate and gradually decreasing or constant heart rate; (b) separating fluctuations from slow trends in said at least one QT and RR interval data set; (c) comparing said QT and RR fluctuations to one another to determine the statistical and functional relationships therebetween; and (d) generating from the comparison of step (c) partial measures of risk of cardiac arrhythmia in said subject. A greater difference between QT and RR fluctuations indicates greater risk of cardiac arrhythmia in said subject. A smaller degree of functional relationship between the fast RR fluctuations and immediately following QT fluctuations indicates a higher risk of cardiac arrhythmia. A smaller degree of functional relationship between the fast RR fluctuations and all subsequent QT fluctuations indicates a higher risk of cardiac arrhythmia. The data sets are collected in such a manner that they reflect almost exclusively the conduction in the heart muscle and minimize the effect on the data sets of rapid transients due to autonomic nervous system and hormonal control.