A method for acquiring cardiac information from a patient having a pacer for pacing a heart rhythm, an abnormal EKG, or an abnormal heartbeat is disclosed. The method includes: placing a signal injection device proximate the pacer of the patient and injecting a signal across a skin barrier of the patient toward the pacer; in response to the signal received at the pacer, pacing the patient's heart in a fixed asynchronous pacing mode; and, acquiring cardiac information relating to the patient's fixed asynchronously paced heart.