Method and apparatus for verifying a determined cardiac event in a medical device based on detected variation in hemodynamic status

[0023]FIG. 1 is a schematic diagram of an exemplary medical device in which the present invention may be usefully practiced. As illustrated in FIG. 1, the present invention may be utilized in an implantable medical device 14 that includes a housing 15 containing circuitry for operating device 14 that is subcutaneously implanted in a patient, outside the ribcage of patient 12, anterior to the cardiac notch, for example. According to an embodiment of the present invention, housing 15 may be implanted in the pectoral region of the patient 12. Further, device 14 may include a subcutaneous sensing and cardioversion / defibrillation therapy delivery lead 18 coupled to the device 14 that is tunneled subcutaneously into a location adjacent to a portion of a latissimus dorsi muscle of patient 12. Specifically, lead 18 is tunneled subcutaneously from the median implant pocket of device 14 laterally and posterially to the patient's back to a location opposite the heart such that the heart 16 is d