Multiple ICD discharges associated with lead fracture without triggering of high impedance alert.

The Sprint Fidelis lead has an increased incidence of lead fracture. The manufacturer has recommended programming alerts to preempt lead malfunction due to fracture. The current trigger for an alert is an increase in the right ventricular pacing impedance to greater than 1,000 Omega. Our patient suffered multiple inappropriate implantable cardioverter defibrillator therapies with stable impedance less than 1,000 Omega. This case of lead fracture would not have been detected with these programming alerts. Additional programming measures may detect lead fractures, including changing the lower detection for impedances, arranging for a percentage change in the impedance trend to trigger an alarm, or programming the device to warn if there is an increase in nonphysiologic short R-R interval counts.