An implantable medical device and method are provided for comprising a sensing circuit that is configured to sense and output physiologic data indicative of a physiologic characteristic of a patient and at least one processor. A memory is coupled to the at least one processor. The memory stores program instructions and processed data. The program instructions are executable by the at least one processor to execute general operational functions within the IMD. A hybrid signal processing (HSP) circuit is coupled to the at least one processor and the sensing circuit. The HSP circuit is adapted to filter the physiologic data. The HSP circuit comprises a plurality of first order filters, a plurality of higher order filters, and a switch matrix that is configured to interconnect a combination of the first and higher order filters to form a hybrid digital filter having a select composite frequency response that utilizes no more than a select power demand.