Patent ID: 8639331

Claim:
A method for operating an implantable medical device (IMD) implanted within a patient in the presence of a magnetic resonance imaging (MRI) environment, the method comprising: receiving a therapy command from an external device while the IMD is in the presence of an MRI electromagnetic field and is operating in a first operational mode in which one or more sensors of the IMD have been disabled, the therapy command configured to prompt the IMD to provide immediate therapy to the patient while in the MRI electromagnetic field; and placing the IMD in a second operational mode upon receiving the therapy command, wherein the second operational mode includes: enabling the one or more sensors of the IMD; determining whether a tachyarrhythmia is present using the one or more sensors; and delivering antitachycardia pacing (ATP) therapy to the patient if a tachyarrhythmia is determined to be present, wherein shock therapy is not delivered by the IMD when in the second operational mode if tachyarrhythmia is determined to be present while the IMD is in the presence of the MRI electromagnetic field.