DIAGNOSIS OF ICD LEAD FAILURE USING CONTINUOUS EVENT MARKER RECORDING

Stored electrograms enhance the ability to evaluate therapy episodes i n the third-generation implantable cardioverter defibrillator. These e lectrograms are recorded from either the shocking or rate sensing lead s, but not both. As a result, differentiation of certain types of sens ing abnormalities may be difficult prior to surgical exploration. We p resent a case of rate sensing lead failure due to an insulation break. Several minutes of recording of the event marker in the laboratory fa iled to document any abnormal sensing; the diagnosis was made by recor ding the event marker on a 24-hour continuous (Holter) monitor. The Ho lter monitor/event marker combination was of substantial diagnostic va lue and allowed for a more focused surgical evaluation and treatment.