Pacemaker enabled ischemia detection with selective ischemia tests

摘要

A device for detecting cardiac ischemia is disclosed. The device includes a processor that is configured to distinguish between two different heart beats types such as ventricularly paced beats and supraventricular beats. The processor collects separate reference data for a first one of the beat types indicative of the normal values of a cardiac feature. The processor performs an ischemia test to beats of the first type by first checking whether valid reference data exists for that beat type. If so, the ischemia test is based on this reference data. If no valid reference data exists for the first beat type, the processor applies an ischemia test that is not based on reference data for the first beat type.

主权项

1. An implantable device to detect ischemic events, including:
at least one electrode adapted for implantation in a body; circuitry coupled to the electrode to sense signals therefrom and to generate corresponding digital signals; a processor configured to:
identify beats in the digital signals associated with a first beat type and a second beat type;analyze the digital signals to collect reference data for the first beat type and the second beat type to determine a first beat baseline and a second beat baseline, wherein the reference data pertains to a first heart signal parameter;measure from the digital signals a plurality of values of the first heart signal parameter for a plurality of beats of the first and second beat types;determine a number of heart signal parameter values existing for the first beat type;determine whether the number of heart signal parameter values for the first beat type is greater than a predetermined threshold value, said predetermined threshold value defining valid reference data;operative when valid reference data exists for the first beat type, apply a first ischemia test that is based at least in part on a comparison of the plurality of values of the first heart signal parameter with said first beat baseline associated with the reference data for the first beat type; andoperative when valid reference data does not exist for the first beat type, apply a second ischemia test to the plurality of beats of the first beat type, said second ischemia test being based upon said second beat baseline.