Alterations in implantable cardioverter defibrillator lead parameters following left ventricular assist device implantation

Background

Left ventricular assist devices (LVADs) are increasingly used in the management of advanced heart failure. The majority of these patients have pre-existing implantable cardioverter defibrillators (ICDs). The proximity between the LVAD inflow cannula and right ventricular (RV) defibrillation lead raises the potential for disruption of ICD function.

Methods

This is a retrospective analysis of 95 patients with ICDs at a single tertiary care center who underwent LVAD implantation and who met inclusion criteria. The primary outcome was changes in the pre-operative and post-operative transvenous ICD RV lead parameters. These changes were stratified by the age of the RV lead and analyzed via a paired t-test. The secondary outcome was disruption to the ICD requiring an intervention.

Results

LVAD implantation was associated with significant decreases in sensed amplitude (p < 0.01) and high voltage impedance (p < 0.01) and an increase in capture threshold (p = 0.017). When stratified by age of the RV lead, patients with leads older than two years had similar trends in all parameters. However, RV leads that were two years old or younger only showed a significant change in high voltage impedance (p < 0.01). Mechanical disruption of the ICD related to the surgery was infrequent but significant.

Conclusion

Because LVAD implantation is capable of impacting ICD function and causing mechanical disruption, close monitoring should be paid to the ICD in the peri-operative period including obtaining a full interrogation.