Diagnosis of ICD Lead Failure Using Continuous Event Marker Recording

HORTON, R.P., et.al.: Diagnosis of ICD Lead Failure Using Continuous Event Marker Recording. Stored electrograms enhance the ability to evaluate therapy episodes in the third‐generation implantable cardioverter defibrillator. These electrograms are recorded from either the shocking or rate sensing leads, but not both. As a result, differentiation of certain types of sensing abnormalities may be difficult prior to surgical exploration. We present a case of rate sensing lead failure due to an insulation break. Several minutes of recording of the event marker in the laboratory failed to document any abnormal sensing; the diagnosis was made by recording the event marker on a 24‐hour continuous (Holter) monitor. The Holter monitor/event marker combination was of substantial diagnostic value and allowed for a more focused surgical evaluation and treatment.