Method and apparatus for prediction of cardiac electrical instability by simultaneous assessment of T-wave alternans and QT interval dispersion

An apparatus for predicting cardiac electrical stability, comprising:

• means for receiving an ECG of a patient's heart;
• first means for detecting and analyzing beat-to-beat alternation in a T-wave of said ECG to assess excitable stimulus and heterogeneity of repolarization;
• second means for detecting and analyzing dispersion of repolarization in said ECG to assess heterogeneity of repolarization;
• and
• third means for simultaneously analyzing assessment of excitable stimulus and heterogeneity of repolarization from said first means and heterogeneity of repolarization from said second means to assess cardiac electrical stability.

The apparatus of claim 18, wherein said second means comprises:

• means for locating the peak amplitude in each R-R interval to find the apex of each R-wave in each of said plurality of ECG signals;
• means for determining the temporal location of the beginning of each Q-wave based on the apex of each R-wave;
• means for determining the temporal location of the end of each T-wave;
• means for calculating each QT interval as a time difference from the beginning of the Q-wave to the end of the T-wave;
• and
• means for estimating a measure of dispersion of repolarization of said QT intervals across said plurality of ECG signals.