Atrioventricular Synchrony Delivered by a Dual-Chamber Leadless Pacemaker System.

Background: A dual-chamber leadless pacemaker system has been designed for atrioventricular synchronous pacing using wireless, beat-to-beat, implant-to-implant (i2i) communication between distinct atrial and ventricular leadless pacemakers. The atrioventricular synchrony achieved across various ambulatory scenarios has yet to be systematically evaluated.

Methods: A prospective, single-arm, unblinded, multicenter, international clinical trial of the leadless pacemaker system was conducted in patients with a conventional dual-chamber pacing indication enrolled from February 2022 to March 2023.

Six-month electrical performance of the first dual-chamber leadless pacemaker.

Background: The first dual-chamber leadless pacemaker (DC-LP) system consists of 2 separate atrial and ventricular devices that communicate to maintain synchronous atrioventricular pacing and sensing. The initial safety and efficacy were previously reported.

Objective: The purpose of this study was to evaluate the chronic electrical performance of the DC-LP system.

Early real-world implant experience with a helix-fixation ventricular leadless pacemaker.

Background: Roughly one in six patients receiving conventional transvenous pacemaker systems experience significant complications within 1 year of implant, mainly due to the transvenous lead and subcutaneous pocket. A new helix-fixation single-chamber ventricular leadless pacemaker (LP) system capable of pre-deployment exploratory electrical mapping is commercially available. Such an LP may mitigate complications while streamlining the implantation.

Retrieval of Chronically Implanted Dual-chamber Leadless Pacemakers in an Ovine Model.

Background: The clinical utilization of leadless pacemakers (LPs) as an alternative to traditional transvenous pacemakers is likely to increase with the advent of dual-chamber LP systems. Since device retrieval to allow LP upgrade or replacement will become an important capability, the first such dual-chamber, helix-fixation LP system (Aveir DR; Abbott, Abbott Park, IL) was specifically designed to allow catheter-based retrieval. In this study, the preclinical performance and safety of retrieving chronically implanted dual-chamber LPs was evaluated.

Novel algorithms improve arrhythmia detection accuracy in insertable cardiac monitors.

Introduction: Insertable cardiac monitors (ICMs) are commonly used to diagnose cardiac arrhythmias. False detections in the latest ICM systems remain an issue, primarily due to inaccurate R-wave sensing. New discrimination algorithms were developed and tested to reduce false detections of atrial fibrillation (AF), pause, and tachycardia episodes in ICMs.

Dual-chamber leadless pacing: Atrioventricular synchrony in preclinical models of normal or blocked atrioventricular conduction.

Background: Dual-chamber leadless pacemakers (LPs) require robust communication between distinct right atrial (RA) and right ventricular (RV) LPs to achieve atrioventricular (AV) synchrony.

Objective: The purpose of this preclinical study was to evaluate a novel, continuous implant-to-implant (i2i™) communication methodology for maintaining AV-synchronous, dual-chamber DDD(R) pacing by the 2 LPs.

Methods: RA and RV LPs were implanted and paired in 7 ovine subjects (4 with induced complete heart block).

Electrocardiographic imaging demonstrates electrical synchrony improvement by dynamic atrioventricular delays in patients with left bundle branch block and preserved atrioventricular conduction.

Aims: Cardiac resynchronization therapy programmed to dynamically fuse pacing with intrinsic conduction using atrioventricular (AV) timing algorithms (e.g. SyncAV) has shown promise; however, mechanistic data are lacking.

Wireless Communication Between Paired Leadless Pacemakers for Dual-Chamber Synchrony.

Background: Leadless pacemakers (LPs) can mitigate conventional pacemaker complications related to the transvenous leads and subcutaneous pocket surrounding the pulse generator. Although single-chamber leadless pacing has been established, multichamber pacing requires wireless bidirectional communication across multiple LPs to maintain synchrony. This preclinical study demonstrates the chronic performance of implant-to-implant (i2i) communication that achieves synchronous, dual-chamber pacing with 2 LPs.

Acute hemodynamic impact of atrioventricular delay and left ventricular pacing vector programming in MultiPoint Pacing.

Background: The benefits of cardiac resynchronization therapy (CRT) in heart failure patients have been shown to depend on device programming, particularly atrioventricular delay (AVD) and left ventricular (LV) pacing site selection. This study compared the hemodynamic AVD optimization for commonly used biventricular (BiV) and MultiPoint Pacing(MPP, Abbott) LV vector selection strategies.

Methods: After de novo CRT-D (Abbott Quadra Assura MP) and quadripolar LV lead (Abbott Quartet) implant, acute LV pressure was measured across a range of AVDs (60-225 ms) in four pacing modes: BiV with most proximal cathode, BiV with most distal cathode, MPP using two cathodes with earliest and latest right ventricle (RV)-LV activation times, and MPP using two cathodes with maximal anatomical separation.

Reducing the electrogram review burden imposed by insertable cardiac monitors.

Background: Insertable cardiac monitors (ICMs) are essential for ambulatory arrhythmia diagnosis. However, definitive diagnoses still require time-consuming, manual adjudication of electrograms (EGMs).

Objective: To evaluate the clinical impact of selecting only key EGMs for review.

Preclinical safety and electrical performance of novel atrial leadless pacemaker with dual-helix fixation.

Background: Complications associated with transvenous pacemakers, specifically those involving the lead or subcutaneous pocket, may be avoided with leadless pacemakers (LPs). The safety and efficacy of single-chamber right ventricular LPs have been demonstrated, but their right atrium (RA) use poses new design constraints.

Objectives: The purpose of this study was to evaluate the implant success, electrical performance, and safety of a novel RA LP design in benchtop and preclinical studies.

Ventricular activation patterns during intrinsic conduction and right ventricular pacing in cardiac resynchronization therapy patients.

Background: Cardiac resynchronization therapy (CRT) involves stimulation of both right ventricle (RV) and left ventricle (LV). LV pacing from the sites of delayed electrical activation improves CRT response. The RV-LV conduction is typically measured in intrinsic rhythm.

Clinical impact of MultiPoint pacing in responders to cardiac resynchronization therapy.

Background: Cardiac resynchronization therapy demonstrated benefits in heart failure. However, only 60-70% are responders and only 22% are super-responders. MultiPoint pacing (MPP) improves structural remodeling, but data in responder patients is scarce.

Long-term reverse remodeling and clinical improvement by MultiPoint Pacing in a randomized, international, Middle Eastern heart failure study.

Purpose: Cardiac resynchronization therapy (CRT) with multipoint left ventricular (LV) pacing (MultiPoint™ Pacing, MPP) has been shown to improve CRT response, although MPP response using automated pacing vector programming has not been demonstrated in the Middle East. The purpose of this study was to compare the impact of MPP to conventional biventricular pacing (BiV) using echocardiographic and clinical changes at 6-month post-implant.

Methods: This prospective, randomized study was conducted at 13 Middle Eastern centers.

Assessing hemodynamic response to submaximal exercise in pulmonary arterial hypertension patients using an implantable hemodynamic monitor.

Pulmonary arterial hypertension (PAH) is a chronic, progressive disease that is incurable, even with effective therapy. Long-term outcome in PAH is best preserved by targeting hemodynamic improvements to reduce risk of subsequent right ventricular (RV) failure. Methods that can assess RV adaptation to stress have important implications to better understand an individual's physiology and may play a pivotal role in guiding therapy in PAH.

Electrical synchronization achieved by multipoint pacing combined with dynamic atrioventricular delay.

Purpose: Multipoint pacing (MPP) improves left ventricular (LV) electrical synchrony in cardiac resynchronization therapy (CRT). SyncAV automatically adjusts atrioventricular delay (AVD) according to intrinsic AV intervals and may further improve synchrony. Their combination has not been assessed.

Extending multipoint pacing CRT battery longevity by swapping left ventricular pulse configurations.

Purpose: Cardiac resynchronization therapy (CRT) with left ventricular (LV) MultiPoint™ pacing (MPP) has been shown to improve CRT response by pacing two LV sites (LV1, LV2). While an additional LV pacing site reduces battery longevity, this cost can be minimized by leveraging an existing device-based capture management algorithm (LVCap™ Confirm). The purpose of this study was to evaluate the MPP battery longevity improvement achieved by configuring LV pacing sites to properly leverage LVCap Confirm.

Dynamic atrioventricular delay programming improves ventricular electrical synchronization as evaluated by 3D vectorcardiography.

Background: Optimal timing of the atrioventricular delay in cardiac resynchronization therapy (CRT) can improve synchrony in patients suffering from heart failure. The purpose of this study was to evaluate the impact of SyncAV™ on electrical synchrony as measured by vectorcardiography (VCG) derived QRS metrics during bi-ventricular (BiV) pacing.

Methods: Patients implanted with a cardiac resynchronization therapy (CRT) device and quadripolar left ventricular (LV) lead underwent 12‑lead ECG recordings.

Monitoring Pulmonary Arterial Hypertension Using an Implantable Hemodynamic Sensor.

Background: Pulmonary arterial hypertension (PAH) is a chronic disease that ultimately progresses to right-sided heart failure (HF) and death. Close monitoring of pulmonary artery pressure (PAP) and right ventricular (RV) function allows clinicians to appropriately guide therapy. However, the burden of commonly used methods to assess RV hemodynamics, such as right heart catheterization, precludes frequent monitoring.

Dynamic programming of atrioventricular delay improves electrical synchrony in a multicenter cardiac resynchronization therapy study.

Background: Patient-specific programming of cardiac resynchronization therapy (CRT) is often neglected, despite significant nonresponse rates. The device-based SyncAV CRT algorithm dynamically adjusts atrioventricular delays to the intrinsic AV interval, reduced by a programmable offset, to accommodate each patient's changing needs.

Objective: The purpose of this study was to evaluate the acute effect of biventricular (BiV) pacing enhanced by SyncAV on electrical synchrony in a broad patient population.

Long-term reverse remodeling by cardiac resynchronization therapy with MultiPoint Pacing: A feasibility study of noninvasive hemodynamics-guided device programming.

Background: Cardiac resynchronization therapy (CRT) with multipoint left ventricular (LV) pacing (MultiPoint Pacing [MPP]) improves acute hemodynamics and chronic outcomes in comparison to conventional biventricular pacing (BiV), though MPP programming questions persist.

Objectives: In this multicenter feasibility study, we evaluated the feasibility of using noninvasive systolic blood pressure (SBP) to guide MPP programming and assessed the chronic 6-month echocardiographic CRT response.

Methods: Patients implanted with MPP-enabled CRT-defibrillator devices underwent noninvasive hemodynamic assessment (finger arterial pressure) during a pacing protocol that included atrial-only pacing and various BiV and MPP configurations.

Complications and Health Care Costs Associated With Transvenous Cardiac Pacemakers in a Nationwide Assessment.

Objectives: The aim of this study was to retrospectively characterize transvenous pacemaker (TVP) complications and associated health care costs in a large-scale U.S. patient cohort.