Automatic determination and selection of filtering in a cardiac rhythm management device

A cardiac rhythm management device (CRMD) comprising plural sensing electrodes for capturing a cardiac signal and operational circuitry coupled to the plural sensing electrodes for analyzing the cardiac signal, the operational circuitry configured with a selectable filtering mode allowing filtering of the captured cardiac signal according to a first approach and a second approach, the second approach applying an additional high pass filter relative to the first approach, wherein the operational circuitry is configured to operate using the selectable filtering mode as follows:

• filtering cardiac signals with the second approach and analyzing the cardiac signals that have been filtered with the second approach to detect cardiac cycles;
• determining that conditions indicate a termination of the second approach is appropriate by analyzing intervals between detected cardiac cycles and determining that plural such intervals exceed one or more predefined thresholds;
• and
• switching to use of the first approach for filtering the cardiac signals.