Appropriate and inappropriate ICD shocks in patients with LVADs: Prevalence, associated factors, and etiologies.

BACKGROUND

Implantable cardioverter-defibrillator (ICD) shocks are a common complication after left ventricular assist device (LVAD) implantation; however, data on their frequency and causes are limited.

OBJECTIVE

The purpose of this study was to define the incidence, programming, patient characteristics, and factors associated with appropriate and inappropriate ICD shocks in persons with LVADs.

METHODS

We performed a retrospective review at Duke University Hospital of all LVAD recipients implanted between January 1, 2013, to June 30, 2019, with a preexisting ICD. ICD shocks were adjudicated by the treating physician and a second reviewer for the purpose of this study.

RESULTS

Among 421 patients with an ICD in situ undergoing LVAD implant, 147 (33.9%) had at least 1 shock after LVAD implantation. Among 134 patients with complete device history, a total of 330 shock episodes occurred: 255 (77.3%) appropriate and 75 (22.7%) inappropriate. Etiologies for inappropriate shocks included supraventricular tachycardia (n = 66 [20.0%]), physiological oversensing (n = 1 [0.3%]), and nonphysiological oversensing (n = 8 [2.4%]) including LVAD electromagnetic interference (n = 1 [0.3%]). ICD programming with shorter detection delay (P <.001) and absence of antitachycardia pacing programming (P = .001) in high-rate zones was seen more commonly in inappropriate shock than appropriate shock.

CONCLUSIONS

The rate of inappropriate shocks in LVAD recipients is very high and most often is due to supraventricular arrhythmias. LVAD electromagnetic interference is a rare cause of ICD shock. Implementation of current consensus American Heart Association recommendations for LVAD programming with long detection delays and high rate cutoffs may help prevent inappropriate ICD shocks.