Method and apparatus for detecting and displaying p-wave and r-wave histograms for an implant medical device

Abstract

A pacemaker, or other implantable medical device, connected to heart tissue, detects atrial and ventricular electrical signals. The pacemaker analyzes the signals to determine whether the signals are representative of P-waves or R-waves according to atrial and ventricular sensitivity threshold values. Signals determined to be P-waves or R-waves are identified as sensed signals. Otherwise the signals are identified as not-sensed signals. The pacemaker further determines whether the sensed signals were detected during a refractory period or an alert period and its current tracking mode (e.g., VDD, DDD vs. DDI, VVI). Information pertaining to these atrial and ventricular signals is transmitted to an external programmer which generates representative histograms. The histograms present the number of counts detected within each of a set of high pass filtered amplitude ranges and further indicate the relative numbers of sensed vs. not-sensed counts. For the sensed counts, the histogram may further indicate the relative numbers of counts detected during refractory periods and alert periods. The histograms additionally show the applicable atrial or ventricular sensitivity threshold values to visually assist a physician in determining whether the threshold values are set properly. An auto-sensitivity adjustment system is also provided to determine optimal sensitivity threshold values.