Patent ID: 7177689
Filing Date: 2007-02-13
Classification: A61N

Abstract:
1. A system for determining capture thresholds for a multi-site cardiac pacemaker, comprising: a pacemaker having: (a) first and second pacing channels with each such channel comprising an electrode for disposing new a chamber of the heart, a pulse generator for outputting pacing pulses, and a channel interface for adjusting the pacing pulse energy, (b) a controller for controlling the operation of the pulse generators in accordance with a programmed pacing mode such that first and second pacing pulses are delivered from the first and second pacing channels, respectively, to one or both of the paired atria or to one or both of the paired ventricles during a cardiac cycle, and (c) a telemetry interface for communicating with an external programmer; an external programmer having a controller for processing data received from the pacemaker, wherein the controller is programmed to: generate a dual-channel capture template by recording a depolarization waveform produced when first and second pacing pulses are delivered from the first and second pacing channels at an energy sufficient to achieve capture by each of the first and second pacing pulses, generate a first channel capture template by recording a depolarization waveform produced when first pacing pulses are delivered from the first pacing channel at an energy sufficient to achieve capture by the first pacing pulses with no pacing pulses delivered by the second pacing channel, generate a second channel capture template by recording a depolarization waveform produced when second pacing pulses are delivered from the second pacing channel at an energy sufficient to achieve capture by the second pacing pulses with no pacing pulses delivered by the first pacing channel, record a test depolarization waveform when pacing pulses are delivered from the first and second pacing channels, compare the test depolarization waveform to the dual-channel capture template, the first channel capture template, and the second channel capture template, determine that both the first and second pacing channels have achieved capture if the test depolarization waveform matches the dual-channel capture template; determine that the first pacing channel has failed to achieve capture if the test depolarization waveform does not match the dual-channel capture template but matches the second channel capture template, determine that the second pacing channel has failed to achieve capture if the test depolarization waveform does not match the dual-channel capture template but matches the first channel capture template, and determine that neither the first nor the second pacing channel has achieved capture if the test depolarization waveform matches neither the dual-channel capture template, the first channel capture template, nor the second channel capture template.