Patent ID: 8255043

Claim:
A method, for use in an implantable medical device, to determine the start and end of a T-wave based on heart rate comprising: detecting heart rate over a period of time, wherein the period of time is an R-R interval and wherein the heart rate is between about 50 bpm to about 160 bpm; using a microprocessor to calculate a T-wave start time using the formula: T start = 160 ( Heart ⁢ ⁢ Rate 60 ) 0.5 ; using a microprocessor to calculate a T-wave end time using the formula: T end = 480 ( Heart ⁢ ⁢ Rate 70 ) 0.7 . where T start and T end are the start and end time from the peak of a QRS; determining the T-wave duration as the time between T start and T end ; and recording the T-wave duration.