Patent ID: 8055342
Filing Date: 2011-11-08
Classification: A61N

Abstract:
1. A method for automatically adjusting a sensing threshold in a cardiac rhythm management device, comprising: sensing a ventricular electrogram signal via a ventricular sensing channel and detecting an r-wave when the sensed ventricular signal exceeds a ventricular sensing threshold; sensing an atrial electrogram signal via an atrial sensing channel and detecting a p-wave when the sensed atrial signal exceeds an atrial sensing threshold; measuring the noise level of the atrial sensing channel during a refractory period; when no p-wave is detected and an atrial pace is delivered during a current cardiac cycle, decreasing the atrial sensing threshold by a first specified amount unless the noise level of the atrial sensing channel has increased by a specified amount; and when no p-wave is detected and an r-wave is detected during a current cardiac cycle so as to represent either a premature ventricular contraction or an atrial undersense, decreasing the atrial sensing threshold by a second specified amount.