Patent ID: 7574259
Filing Date: 2009-08-11
Classification: A61N

Abstract:
1. A method to detect an insulation and/or a conductor defect in a lead, said method comprising: delivering a first primary ventricular cardiac stimulus at a predetermined atrio-ventricular interval and at a first predetermined energy value using a unipolar electrode configuration comprising a first electrode of the lead, wherein the first predetermined energy value corresponds to a predetermined capture threshold that has in the past produced a ventricular depolarization signal having an amplitude sufficient to register as a first ventricular evoked response; sensing for the first ventricular evoked response using a bipolar electrode configuration comprising the first electrode and a second electrode of the lead; if a first ventricular evoked response was not sensed by the bipolar electrode configuration, then, delivering a second primary ventricular cardiac stimulus after an additional atrial pace or atrial sense at a different atrio-ventricular interval using the unipolar electrode configuration and a second predetermined energy value, wherein the second predetermined energy value is at least equal to the first predetermined energy value; sensing for the second ventricular evoked response using the bipolar electrode configuration; if the second ventricular evoked response was not sensed by the bipolar electrode configuration outputting a high-energy ventricular cardiac stimulus at an energy level greater than the first and second predetermined energy levels using the bipolar electrode configuration of the lead; sensing for a ventricular evoked response that should be produced by the high-energy ventricular cardiac stimulation using the unipolar electrode configuration; if no ventricular evoked response from the high-energy ventricular cardiac stimulation is sensed, determining that a fault condition exists for the bipolar configuration.