Identifying lead problems using amplitudes of far-field cardiac events

摘要

An implantable medical device capable of sensing cardiac signals and delivering cardiac electrical stimulation therapies is enabled to detect a short circuit condition on a sensing or therapy vector. A cardiac signal is sensed by a sensing module coupled to electrodes. A control module detects a short circuit condition in response to a significant drop in amplitude of far-field cardiac events coincident to near-field cardiac events. In some instances, the short circuit condition is detected in response an abnormal impedance on the far-field sensing vector and/or a matching morphology of the far-field cardiac electrical signal including the coincident FF cardiac event in addition to the significant drop in amplitude of the coincident FF cardiac events.

主权项

1. A method comprising:
obtaining a near-field (NF) cardiac electrical signal sensed via a NF sensing vector between a first pair of electrodes located within a first chamber of a heart; obtaining a far-field (FF) cardiac electrical signal sensed via a FF sensing vector between a second pair of electrodes, wherein at least one of the second pair of electrodes is located outside the first heart chamber of the heart; detecting a NF cardiac event in the NF cardiac electrical signal; determining an amplitude of a FF cardiac event in the FF cardiac electrical signal coincident the detected NF cardiac event; comparing the amplitude of the coincident FF cardiac event to a threshold amplitude; and detecting a short circuit condition on the FF sensing vector when the amplitude of the coincident FF cardiac event is less than the threshold amplitude.