A mechanism controlling the characteristics of T-wave alternans measurements in the setting of myocardial ischemia

T-Wave alternans (TWA) is a variation in the morphology of the T wave of the electrocardiogram (ECG) that repeats on an every other beat basis. In recent clinical studies, its presence has shown to be highly predictive of the occurrence of lethal ventricular arrhythmias. Measurements of TWA using power spectral analysis of the ECG signals have shown that the power at the alternans frequency (0.5 cycles per beat) increases with heart rate following onset at a patient-specific heart rate threshold. The mechanisms underlying these phenomena have not been fully established. In this paper, we report a mechanism that can account for these two phenomena in the setting of myocardial ischemia