Electromagnetic Interference from Left Ventricular Assist Device (LVAD) Inhibiting the Pacing Function of an Implantable Cardioverter-Defibrillator (ICD) Device

Effects of medically generated electromagnetic interference from medical devices on cardiac implantable electronic devices: A review

As cardiac implantable electronic devices (CIED) become more prevalent, it is important to acknowledge potential electromagnetic interference (EMI) from other sources, such as internal and external electronic devices and procedures and its effect on these devices. EMI from other sources can potentially inhibit pacing and trigger shocks in permanent pacemakers (PPM) and implantable cardioverter defibrillators (ICD), respectively. This review analyzes potential EMI amongst CIED and left ventricular assist device, deep brain stimulators, spinal cord stimulators, transcutaneous electrical nerve stimulators, and throughout an array of procedures, such as endoscopy, bronchoscopy, and procedures involving electrocautery. Although there is evidence to support EMI from internal and external devices and during procedures, there is a lack of large multicenter studies, and, as a result, current management guidelines are based primarily on expert opinion and anecdotal experience. We aim to provide a general overview of PPM/ICD function, review documented EMI effect on these devices, and acknowledge current management of CIED interference.

A review of new-onset ventricular arrhythmia after left ventricular assist device implantation

INTRODUCTION

Heart failure (HF) is a severe and terminal stage of various heart diseases. Left ventricular assist devices (LVADs) are relatively mature and have contributed to the treatment of end-stage HF. Ventricular arrhythmia (VA) is a common complication after LVAD implantation, including ventricular tachycardia and ventricular fibrillation, both of which may cause abnormal circulation in the body.

METHODS

A literature search was conducted in the PubMed database, "Ventricular Arrhythmia" OR "VA" OR "Arrhythmia" OR "Ventricular Tachycardia," OR "Ventricular Fibrillation" AND "LVAD" OR "Left Ventricular Assist Device" OR "Heart Assist Device" as either keywords or MeSH terms, the authors screened the titles and abstracts of the articles. Eventually, 12 original research articles were retrieved.

RESULTS

The 0.83 [95%CI: 0.77, 0.89] of patients were male. A whole of 53% [95%CI:0.25, 0.81] of VA patients had a history of atrial fibrillation and 61% [95%CI:0.52, 0.69] had a history of VA. 39% [95%CI:0.29, 0.49] of the participants had no prior history of VA and experienced new VA following CF-LVAD implantation. Following CF-LVAD implantation, 59% [95%CI:0.51, 0.67] of patients developed the early VA (VA ≤ 30 days). The 30-day mortality of patients was 4% [95%CI:0.01, 0.07]. And overall mortality was 28% [95%CI:0.15, 0.41] The reported incidence of VA after LVAD implantation is not identical in different medical centers and ranges from 20% to 60%. The mechanism of VA after LVAD implantation is summarized as primary cardiomyopathy-related, device mechanical stimulation, myocardial scarring, ventricular displacement, electrolyte regulation, and other processes.

CONCLUSIONS

A preoperative VA history is considered a predictor of VA following LVAD implantation in most studies. Multiple mechanisms and factors, such as prevention of "suction events", ablation, and ICD, should be considered for the prevention and treatment of postoperative VA in patients requiring long-term VAD treatment. This study provides a reference for the clinical application of LAVD and the prevention of postoperative VA after LVAD implantation. Future multicenter prospective studies with uniform patient follow-up are needed to screen for additional potential risk factors and predictors. These studies will help to define the incidence rate of VA after LAVD implantation. As a result, we provide guidance for the selection of preventive intervention.

Suppression of electromagnetic interference in electroretinography from a patient with an implanted left ventricular assist device (LVAD)

PURPOSE

A left ventricular assist device (LVAD) is an implantable cardiac pump that uses a magnetically-levitating rotor to pump blood into circulation for patients with congestive heart failure. The continuous high-frequency motion of the pump can cause significant interference in electroretinography (ERG) recordings. We evaluate filtering methods to improve ERG quality in the presence of LVAD interference.

METHODS

A patient with an implanted LVAD was referred to our clinic for ERG testing on suspicion of a retinal dystrophy. Full-field ERG (ffERG) and pattern ERG (pERG) were performed according to ISCEV standards. Recordings were acquired once in full-bandwidth mode and again in low-bandwidth mode. Digital low-pass and band-stop filtering were performed to mitigate ERG interference. Post-processing was also evaluated in a control subject with no implanted device.

RESULTS

High-frequency interference was present in all ERG recordings and corresponded to the speed settings of the pump. When applied in post-processing, both low-pass and band-stop filters suppressed the interference and presented readable ERGs without affecting peak times or amplitudes. By contrast, when recording in low-bandwidth mode, the filter drop-off was not steep enough to completely remove the interference and peak delays were introduced that could not be readily corrected.

CONCLUSIONS

LVAD interference in ERG waveforms can be successfully removed using simple digital filters. If post hoc data processing capabilities are unavailable, a large amount of interference can be removed by narrowing the acquisition bandwidth and averaging additional repeats of each stimulus response.

Importance of electromagnetic interactions between ICD and VAD devices - mechanistic assessment

BACKGROUND

Implanted cardioverter defibrillators (ICD) and Left Ventricular Assist Devices (LVAD) are established interventions that prolong life in advanced heart failure, but their combination has not been demonstrated as beneficial. Electromagnetic interference (EMI) produced by a LVAD can preclude ICD interrogation with external programmers. We undertook a systematic evaluation of the LVAD-ICD interaction "in-vitro" to clarify the extent of this interaction.

METHODS

Using explanted ICDs and VADs in a mock physiological rig, we assessed interrogation and reprogramming of ICD devices in the presence of a running LVAD. When connectivity between the ICD programmer and the ICD failed, we attempted three different techniques to re-establish connectivity: (1) Electromagnetic shielding of the ICD with a pseudo-faraday cage; (2) altering the LVAD speed; (3) increasing the distance between the VAD and the ICD.

RESULTS

We tested a total of 24 ICDs from different manufacturers in the presence of the Heartware (HW) and HeartMate 3 (HM3) LVADs. With HW, we only observed interaction with Biotronik ICD-devices at very close range (0-6cm). With HM3, only Medtronic ICD devices showed no interaction. Interactions could be mitigated byincreasing the VAD-ICD distance.

CONCLUSIONS

LVADs, notably the HM3, produce EMI that interferes with the communication between an ICD and it's respective programmer. This may need to be considered when choosing the type of VAD to implant in patients with a previously implanted left-sided ICD. The only safe way to regain connectivity is to increase the distance between the VAD and the ICD, with patients raising their arm above their head.

Electromagnetic interference between implantable cardiac devices and continuous-flow left ventricular assist devices: a review

Many patients with continuous-flow left ventricular assist devices (CF-LVAD) have other, co-existing implantable cardiac devices. While such devices often function appropriately, there is potential for electromagnetic interference (EMI). A literature review was performed to identify cases of EMI between CF-LVAD and other implanted cardiac devices to better understand their etiology, outcomes, and the strategies used to overcome such interference. The cases identified included interference between CF-LVAD and pacemakers, implantable cardioverter-defibrillators, and cardiac resynchronization therapy. The EMI reported in the current literature can be broken down into two general categories: interference leading to difficulty establishing telemetry and interference leading to impaired electrical signal sensing. Such interference led to inappropriate shock delivery in some cases. The type of interference, and thus treatments, differed and were device dependent. The strategies employed to reduce interference included metal shielding, physical manipulation to increase the distance between devices, and even exchange of the implanted device with another brand of the same class. To avoid such EMI in the future, physicians must be aware of the reported interference between certain devices, and manufacturers must work more closely to increase the compatibility of implanted cardiac devices.

Influence of a fully magnetically levitated left ventricular assist device on functional interrogation of implantable cardioverter defibrillators

Background

Electromagnetic interference between left ventricular assist devices (LVAD) and the telemetry wand of implantable cardioverter‐defibrillators (ICD) with impairment of ICD interrogation has previously been described in HVAD and HeartMate II devices. This is the first study showing the potential influence of the LVAD model HeartMate 3 (with the unique feature of fully magnetically levitated rotor with consistent wide blood‐flow gaps) on functional interrogation of different ICD models.

Methods and Results

Among 51 patients treated with a HeartMate 3 LVAD, 34 patients (66.7%) already had an ICD implanted prior to LVAD therapy. In this cohort, impairment of ICD interrogation was observed in five patients (14.7%) with five different device models. In patients with Biotronik ICD, stretching of the ipsilateral arm to increase the distance between both devices >10 cm was sufficient in one patients, whereas surgical contralateral repositioning was necessary in two patients; in one further patient no action could be taken, as he died early from embolic stroke. In the only patient with a MicroPort ICD, this issue was resolved by using a wireless telemetry. The distances between both devices showed no statistical significant correlation with an impaired interrogation, neither in the overall collective nor within the groups with the same manufacturer.

Conclusions

In patients with impaired ICD interrogation caused by electromagnetic interference between a HeartMate 3 LVAD and the ICD, the actions mentioned above have to be taken, to resolve this technical issue. Especially, a sufficient distance of at least 10 cm between both devices was crucial for avoiding this problem.