Patent ID: 7930022

Claim:
A process of using an implantable medical device, the process comprising: detecting a tachyarrhythmia of a heart using electrocardiogram (EGM) data obtained with the implantable medical device; delivering a non-stimulatory electrical energy to a left ventricle of the heart during the detected tachyarrhythmia using an endovascular lead configured for coupling to the implantable medical device; determining a myocardial impedance by measuring a response to the non-stimulatory electrical energy at a myocardial tissue site using the endovascular lead, wherein the delivering the non-stimulatory electrical energy includes delivering a current defining a current vector, and wherein measuring a response to the delivered non-stimulatory electrical energy includes measuring a response voltage defining a voltage vector substantially orthogonal to the current vector; determining, during the detected tachyarrhythmia and using the myocardial impedance, information about perfusion to the heart; delivering a less aggressive device therapy type in response to the detected tachyarrhythmia when the myocardial impedance indicates that there is sufficient perfusion to the heart; and delivering a more aggressive device therapy type in response to the detected tachyarrhythmia when the myocardial impedance indicates that there is insufficient perfusion to the heart.