Methods and systems to correlate arrhythmic and ischemic events

#The present invention relates generally to implantable cardiac stimulation devices capable of myocardial ischemia and arrhythmia monitoring.

#Implantable cardiac stimulation devices are currently being used to treat various types of arrhythmias, such as ventricular tachycardia (VT) and ventricular fibrillation (VF). Such devices are capable of detecting the occurrence of an arrhythmia, and automatically applying an appropriate electrical stimulation or shock therapy to the heart aimed at terminating the detected arrhythmia. In addition to providing automatic stimulation, such devices often include a data acquisition system that is configured to acquire intracardiac electrogram (IEGM) signals, convert the raw analog data into digital signals, and store the digital signals for later processing and/or telemetric transmission to an external device.

#Recently, there has been increased interest in adding myocardial ischemia detection capabilities to implantable cardiac devices. Myocardial ischemia, which involves oxygen starvation of the myocardium, can lead to myocardial infarction (MI) and/or the onset of malignant arrhythmias if the oxygen starvation is not alleviated. Although myocardial ischemia is sometimes associated with the symptom of angina pectoris (i.e., chest pain), many episodes of myocardial ischemia are asymptomatic or “silent.” The inclusion of myocardial ischemia detection capabilities within an implantable device can provide a physician with information about a patient's ischemic burden, which is especially useful when the patient is suffering from silent ischemia.

#FIG. 1 is a simplified, partly cutaway view illustrating an implantable stimulation device in electrical communication with at least three leads implanted into a patient's heart for delivering multi-chamber stimulation and shock therapy.

#FIG. 2 is a functional block diagram of the multi-chamber implantable stimulation device of FIG. 1, illustrating the basic elements that provide pacing stimulation, cardioversion, and defibrillation in four chambers of the heart.

#FIG. 3 is a functional block diagram of an exemplary external programmer device that can be used to program the implantable device of FIGS. 1 and 2, and to upload and analyze data collected by the implantable device.

#The following description includes a best mode presently contemplated for the device. This description is not to be taken in a limiting sense but is made merely for the purpose of describing the general principles of the device. In the description that follows, like numerals or reference designators will be used to refer to like parts or elements throughout.

#The disclosed systems and methods are directed to correlating arrhythmic and myocardial ischemic events. Thus, the methods described herein are intended for use with any implantable cardiac device capable of detecting arrhythmias and myocardial ischemic episodes. An exemplary implantable cardiac device will thus be described in conjunction with FIGS. 1 and 2, in which embodiments of the present invention described herein could be implemented. Additionally, FIG. 3 will be used to described an exemplary external programmer that can be used to program an implantable cardiac device, as well as upload information from implantable cardiac devices and analyze such information. It is recognized, however, that numerous variations of such a device exist in which the methods could be implemented.

#Referring to FIG. 1, an exemplary implantable device 110 (also referred to as a pacing device, a pacing apparatus, a stimulation device, or simply a device) is in electrical communication with a patient's heart 112 by way of three leads, 120, 124 and 130, suitable for delivering multi-chamber stimulation. While not necessary to perform embodiments of the present invention, the exemplary device 110 is also capable of delivering shock therapy.