Cardiac Pacemakers, Inc.

Diane Schuster

James O Gilkerson

Scott R Stubbs

Hiten J Doshi

An implantable medical device (IMD) includes a lead having one or more sensing electrodes and one or more therapy delivery electrodes, and a sensor configured to detect the presence of static and time-varying scan fields in a magnetic resonance imaging (MRI) environment. A controller, in electrical communication with the lead and the sensor, is configured to process signals related to tachycardia events sensed via the one or more sensing electrodes and to deliver pacing and shock therapy signals via the one or more therapy delivery electrodes. The controller compares the sensed static and time-varying scan fields to static and time-varying scan field thresholds. The controller controls delivery of anti-tachycardia pacing and shock therapy signals as a function of the detected tachycardia events, the comparison of the sensed static scan field to the static scan field threshold, and the comparison of the time-varying scan fields to the time-varying scan field thresholds.

Implantable medical device with automatic tachycardia detection and control in MRI environments

Systems and methods for arrhythmia therapy in MRI environments are disclosed. Various systems disclosed utilize ATP therapy rather than ventricular shocks when patients are subjected to electromagnetic fields in an MRI scanner bore and shock therapy is not available. As the patient is moved out from within the scanner bore and away from the MRI scanner, the magnetic fields diminish in strength eventually allowing a high voltage capacitor within the IMD to charge if necessary. The system may detect when the electromagnetic fields no longer interfere with the shock therapy and will transition the IMD back to a normal operational mode where shock therapy can be delivered. Then, if the arrhythmia still exists, the system will carry out all of the system's prescribed operations, including the delivery of electric shocks to treat the arrhythmia.

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Bloomington, MN, United States of America

Diane Schuster