Management of cardiac implantable electronic devices in the presence of left ventricular assist devices

Impact of Cardiac Resynchronization Therapy on Ventricular Arrhythmias and Survival After Durable Left Ventricular Assist Device Implantation

The impact of cardiac resynchronization therapy (CRT) in patients receiving durable left ventricular assist device (LVAD) implantation remains unclear and there is no consensus regarding postoperative management. We sought to determine the impact of postoperative management of CRT on clinical outcomes following LVAD implantation. A total of 789 patients underwent LVAD implantation at our institution from 2007 to 2022 including 195 patients (24.7%) with preoperative CRT. Patients with preoperative CRT were significantly older and more frequently received an LVAD as destination therapy compared to patients without preoperative CRT. After LVAD implantation, 85 patients had CRT programmed "off" and 74 patients had CRT programmed "on." The risk of mortality was significantly increased amongst patients with preoperative CRT that was turned "on" following LVAD implantation compared to patients with preoperative CRT turned "off" following implant (subdistribution hazard ratio [sdHR] = 1.54; 1.06-2.37 95% confidence interval [CI]; p = 0.036). There was no significant difference between incidence of ventricular arrhythmias in patients with and without postoperative CRT "on" (35.1% vs. 48.2%; p = 0.095). Additional clinical trials are warranted to determine the best CRT programming strategy following LVAD implantation.

Left ventricular assist device in the presence of subcutaneous implantable cardioverter defibrillator: Data from a multicenter experience

BACKGROUND

Left ventricular assist devices (LVADs) are an increasingly used strategy for the management of patients with advanced heart failure (HF). Subcutaneous implantable cardioverter defibrillator (S-ICD) might be a viable alternative to conventional ICDs with a lower risk of short- and long-term of device-related complications and infections.The aim of this multicenter study was to evaluate the outcomes and management of S-ICD recipients who underwent LVAD implantation.

METHODS

The study population included patients with a preexisting S-ICD who underwent LVAD implantation for advanced HF despite optimal medical therapy.

RESULTS

The study population included 30 patients (25 male; median age 45 [38-52] years).The HeartMate III was the most common LVAD type. Median follow-up in the setting of concomitant use of S-ICDs and LVADs was 7 months (1-20).There were no reports of inability to interrogate S-ICD systems in this population. Electromagnetic interference (EMI) occurred in 21 (70%) patients. The primary sensing vector was the one most significantly involved in determining EMI. Twenty-seven patients (90%) remained eligible for S-ICD implantation with at least one optimal sensing vector. The remaining 3 patients (10%) were ineligible for S-ICD after attempts of reprogramming of sensing vectors. Six patients (20%) experienced inappropriate shocks (IS) due to EMI. Six patients (20%) experienced appropriate shocks. No S-ICD extraction because of need for antitachycardia pacing, ineffective therapy or infection was reported.

CONCLUSIONS

Concomitant use of LVAD and S-ICD is feasible in most patients. However, the potential risk of EMI oversensing, IS and undersensing in the post-operative period following LVAD implantation should be considered. Careful screening for EMI should be performed in all sensing vectors after LVAD implantation.

Impact of ultra-conservative ICD programming in patients with LVADs: Avoiding potentially unnecessary tachy-therapies

BACKGROUND

Patients with left ventricular assist devices (LVAD) often tolerate ventricular arrhythmias (VA). We aim to assess the frequency and outcomes of ICD therapies averted by ultraconservative ICD programming (UCP) in LVAD patients.

METHODS

This single center, retrospective cohort study included patients with LVADs and ICDs implanted from 2015 to 2019 that had UCP. The aim for UCP was to maximally delay VA treatments and maximize anti-tachycardia pacing (ATP) prior to ICD shocks. VA events were reviewed after UCP and evaluated under prior conservative programming to assess for potentially averted events (that would have resulted in either ATP or defibrillation with prior programming).

RESULTS

Fifty patients were included in the study with follow-up of median 16 ± 10.2 months after UCP. The median time from LVAD implantation to reprogramming was 7 days (IQR 5-9 days). Fourteen patients (28%) had potentially averted VA events that would have been treated with their prior ICD programming (82 total events, median two events per patient, IQR 1-10 events). Treated VA events occurred in 15 patients (30%). Eleven of the 14 patients with potentially averted VAs had treated events as well. Only one patient reported definitive symptoms of self-limited "dizziness" during a potentially averted event that did not result in hospitalization. No patients died of complications from or needed emergent care/hospitalization due a potentially averted VA.

CONCLUSIONS

UCP in LVAD patients likely prevented unnecessary VA treatments in many patients with minimal reported symptoms during these potentially averted events. Prospective studies are necessary to confirm these findings.

Electromagnetic interference from left ventricular assist devices detected in patients with implantable cardioverter-defibrillators

INTRODUCTION

Electromagnetic interference (EMI) from left ventricular assist devices (LVADs) can cause implantable cardioverter-defibrillator (ICD) oversensing. We sought to assess the frequency of inappropriate shocks/oversensing due to LVAD-related EMI and prospectively compare integrated (IB) versus dedicated bipolar (DB) sensing in patients with LVADs.

METHODS

Single-center study in LVAD patients with Medtronic or Abbott ICDs between September 2017 and March 2020. We excluded patients that were pacemaker dependent. Measurements were obtained of IB and DB sensing and noise to calculate a signal-to-noise ratio (SNR). Device checks were reviewed to assess appropriate and inappropriate sensing events.

RESULTS

Forty patients (age 52 ± 14 years, 75% men, 38% ischemic cardiomyopathy) were included with the median time between LVAD implantation and enrollment of 6.7 months (2.3, 11.4 months). LVAD subtypes included: HeartWare (n = 22, 55%), Heartmate II (n = 10, 25%), and Heartmate III (n = 8, 20%). Over a follow-up duration of 21.6 ± 12.9 months after LVAD implantation, 5% of patients (n = 2) had oversensing of EMI from the LVAD (both with HeartWare LVADs and Abbott ICDs) at 4 days and 10.8 months after LVAD implantation. Both patients underwent adjustment of ventricular sensing with resolution of oversensing and no further events over 5 and 15 months of further follow-up. The SNR was similar between IB and DB sensing (50 [29-67] and 57 [41-69], p = 0.89).

CONCLUSION

ICD oversensing of EMI from LVADs is infrequent and can be managed with reprogramming the sensitivity. There was no significant difference in the R-wave SNR with IB versus DB ICD leads.

Surface mapping demonstrates compatibility of implantable loop monitor with a continuous-flow left ventricular assist device

Syncope in patients with continuous‐flow left ventricular assist device may be associated with arrhythmia and difficult to determine without an implantable cardioverter defibrillator. We present a patient with continuous‐flow left ventricular assist device, no implantable cardioverter defibrillator, and recurrent syncope. An implantable loop recorder was successfully implanted with surface mapping without noise interference.

Electromagnetic interference from left ventricular assist device in patients with transvenous implantable cardioverter-defibrillator

BACKGROUND

Many advanced heart failure patients have both a left ventricular assist device (LVAD) and an implantable cardioverter-defibrillator (ICD). This study examines incidence, clinical impact, and management of LVAD-related EMI.

METHODS

We performed a three-center retrospective analysis of transvenous ICD implanted patients with LVAD implanted between January 1, 2005 and December 31, 2020. The primary outcome was EMI after LVAD implantation, categorized as LVAD-related noise or telemetry interference.

RESULTS

The rate of LVAD-related EMI among the 737 patients (mean age 58.6 ± 12.8 years) studied was 5.0%. Telemetry interference (1.5%) compromised ICD interrogation in all patients. This was resolved successfully with use of a metal shield, encased wand, radiofrequency tower, different ICD programmer or by increasing distance between ICD programmer and LVAD (n = 6). ICD replacement was required to reestablish successful communication in three patients. LVAD-related noise (3.5%) led to oversensing (n = 4), inappropriate mode switches (n = 4), noise reversion (n = 3), inhibition of pacing (n = 2), inappropriate detection as atrial fibrillation (AF) (n = 2) and inappropriate detection as ventricular tachycardia (VT) and/or ventricular fibrillation (VF) (n = 2). This noise interference persisted (n = 3), resolved spontaneously (n = 16), resolved with programming change (n = 6) or required lead revision (n = 1).

CONCLUSIONS

EMI from LVAD impacts ICD function, although, the incidence rate is low. Physicians implanting both, LVAD in patients with ICD (more common) or ICD in patients with LVAD, should be aware of possible interferences. Telemetry failure not resolved by metal shielding was overcome by ICD generator replacement to a different manufacturer. In most cases, LVAD-related noise resolves spontaneously.

Acute Hemodynamic Effects of Cardiac Resynchronization Therapy Versus Alternative Pacing Strategies in Patients With Left Ventricular Assist Devices

Background

The hemodynamic effects of cardiac resynchronization therapy in patients with left ventricular assist devices (LVADs) are uncharacterized. We aimed to quantify the hemodynamic effects of different ventricular pacing configurations in patients with LVADs, focusing on short‐term changes in load‐independent right ventricular (RV) contractility.

Methods and Results

Patients with LVADs underwent right heart catheterization during spontaneous respiration without sedation and with pressures recorded at end expiration. Right heart catheterization was performed at different pacemaker configurations (biventricular pacing, left ventricular pacing, RV pacing, and unpaced conduction) in a randomly generated sequence with >3 minutes between configuration change and hemodynamic assessment. The right heart catheterization operator was blinded to the sequence. RV maximal change in pressure over time normalized to instantaneous pressure was calculated from digitized hemodynamic waveforms, consistent with a previously validated protocol. Fifteen patients with LVADs who were in sinus rhythm were included. Load‐independent RV contractility, as assessed by RV maximal change in pressure over time normalized to instantaneous pressure, was higher in biventricular pacing compared with unpaced conduction (15.7±7.6 versus 11.0±4.0 s⁻¹; P=0.003). Thermodilution cardiac output was higher in biventricular pacing compared with unpaced conduction (4.48±0.7 versus 4.38±0.8 L/min; P=0.05). There were no significant differences in heart rate, ventricular filling pressures, or atrioventricular valvular regurgitation across all pacing configurations.

Conclusions

Biventricular pacing acutely improves load‐independent RV contractility in patients with LVADs. Even in these patients with mechanical left ventricular unloading via LVAD who were relative pacing nonresponders (required LVAD support despite cardiac resynchronization therapy), biventricular pacing was acutely beneficial to RV contractility.

[ICD and left ventricular assist device interference: Case report]

Left ventricular assist devices are used for severe chronic heart failure management. Many of these patients have an implantable cardioverter defibrillator (ICD). However electromagnetic interferences are possible between the 2 devices. We report here a case of an interference in a 77 years-old patient. This was associated with an impossibility to communicate with the ICD. We discuss how to manage this situation.

Subcutaneous implantable cardioverter defibrillators in patients with left ventricular assist devices: case report and comprehensive review

Background

Left ventricular assist devices (LVAD) are increasingly used in patients with advanced heart failure, many of whom have been or will be implanted with an implantable cardioverter defibrillator (ICD). Interaction between both devices is a matter of concern. Subcutaneous ICD (S-ICD) obtains its signals through subcutaneous vectors, which poses special challenges with regards to adequate performance following LVAD implantation.

Case summary

We describe the case of a 24-year-old man implanted with an S-ICD because of idiopathic dilated cardiomyopathy, severe biventricular dysfunction, and self-limiting sustained ventricular tachycardias. After the implantation of a HeartMate 3™ (Left Ventricular Assist System, Abbott) several months later, the S-ICD became useless because of inappropriate sensing due to electromagnetic interference and attenuation of QRS voltage.

Discussion

We reviewed the reported cases in PubMed about the concomitant use of S-ICD and LVAD. Seven case reports about the performance of S-ICD in patients with an LVAD were identified, with discordant results. From these articles, we analyse the potential causes for these differing results. Pump location and operating rates in LVAD, as well as changes in the subcutaneous-electrocardiogram detected by the S-ICD after LVAD implantation are related to sensing disturbances when used in the same patient.

Usefulness of Cardiac Resynchronization Therapy in Patients With Continuous Flow Left Ventricular Assist Devices

The benefit of cardiac resynchronization therapy in patients supported by a left ventricular assist device (LVAD) is unknown. There are currently no guidelines regarding the continuation, discontinuation or pacemaker (PM) settings post-LVAD implant. The aim of the study was to assess the hemodynamic benefit of biventricular (BiV) pacing in LVAD patients. We studied 22 patients supported by LVADs (age 62 ± 9, 21 males) who had received a BiV PM before LVAD implant. A total of 123 complete sets of hemodynamics were obtained during BiV pacing (n = 54), right ventricular (RV) pacing (n = 54), and intrinsic rhythm (n = 15). There were no significant differences in right atrial (RA) pressure, mean pulmonary artery pressure (mPA), PCWP, cardiac output, PA saturation (PASat) and right ventricular stroke work index between BiV and RV pacing. Hemodynamics obtained during intrinsic rhythm in 15 non-PM-dependent patients were not significantly different compared with those obtained during BiV or RV pacing. Furthermore, hemodynamics were similar at different heart rates ranging 50 to 110 beats/min. Right ventricular stroke work index was significantly lower at the highest heart rate compared with baseline and lowest heart rates suggesting decreased RV performance at higher heart rate. In conclusion, BiV pacing does not have any acute hemodynamic benefit compared with RV pacing or intrinsic rhythm in LVAD patients. A lower heart rate may confer better RV performance.