A method and system for verifying the integrity of normal sinus rhythm (NSR)
templates
and updating the NSR template after selected time intervals. At selected time intervals
after establishing a NSR template, cardiac complexes are sensed and values for
one or more cardiac parameters are measured. The values of the cardiac parameters
are compared to predetermined value ranges for NSR cardiac complexes. When the
values of the cardiac parameters fall within the predetermined value ranges, values
for the differences between the values of the cardiac parameters for the cardiac
complexes and the values for the cardiac parameters of the NSR cardiac complexes
are calculated. When the values of the differences are greater than one or more
threshold values, the NSR template is updated as a function of the sensed cardiac complexes.