In one embodiment, a method for monitoring a heartbeat includes receiving a heartbeat signal, the heartbeat signal including heartbeat cycles. The method also includes determining a region of interest (ROI) of the heartbeat cycles based on an identifying feature of each heartbeat cycle of the heartbeat cycles. The ROI includes a first portion of a period of a first heartbeat cycle. The method also includes sampling the first portion of the heartbeat cycle within the ROI at a first sampling rate and sampling a second portion of the heartbeat cycle outside of the ROI at a second sampling rate less than the first sample rate.
