Physiological Pacing for the Prevention and Treatment of Heart Failure: a State-of-the-Art Review.

Permanent pacing from the right ventricular apex can reduce quality of life and increase the risk of heart failure and death. This review summarizes the milestones in the evolution of pacemakers toward physiological pacing with biventricular pacing systems and lead implantation into the cardiac conduction system to synchronize cardiac contraction and relaxation. Both approaches aim to reproduce normal cardiac activation and help to prevent and treat heart failure.

Atrial fibrillation and heart failure with preserved ejection fraction "twindemic"-Shared root causes and treatment targets.

Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) are comorbid conditions that are increasingly prevalent and have a high socioeconomic burden. This article discusses their shared pathophysiology, focusing on the triad of hypertension, obesity, and aging. We highlight the misperception that pharmacological heart rate lowering is beneficial, which has resulted in an overprescription of β-blockers in HFpEF and AF.

Rationale and design of the PACE HFpEF trial: Physiologic accelerated pacing as a holistic treatment of heart failure with preserved ejection fraction.

Background: In heart failure with preserved ejection fraction (HFpEF), it has been assumed that pharmacologic heart rate suppression should provide clinical benefits through an increase in diastolic filling time. Contrary to this assumption, heart rate lowering in patients with preserved left ventricular ejection fraction and hypertension or coronary artery disease results in adverse outcomes and suggests that the opposite may be beneficial. Namely, shortening the diastolic filling time with a higher heart rate might normalize the elevated filling pressures that are the of HFpEF.

Effects of Continuous Accelerated Pacing on Cardiac Structure and Function in Patients With Heart Failure With Preserved Ejection Fraction: Insights From the myPACE Randomized Clinical Trial.

Background: Heart failure with preserved ejection fraction ≥50% is prevalent with few evidence-based therapies. In a trial of patients with heart failure with preserved ejection fraction with specialized pacemakers, treatment with accelerated personalized pacing averaging 75 bpm (myPACE) markedly improved quality of life, NT-proBNP (N-terminal pro-brain natriuretic peptide), physical activity, and atrial fibrillation burden compared with the standard lower rate setting of 60 bpm (usual care).

Methods And Results: In this exploratory study, provider-initiated echocardiographic studies obtained before and after the trial were assessed for changes in left ventricular (LV) structure and function among participants who continued their pacing assignment.

Personalized accelerated physiologic pacing.

Heart failure with preserved ejection fraction (HFpEF) is increasingly prevalent with a high socioeconomic burden. Pharmacological heart rate lowering was recommended to improve ventricular filling in HFpEF. This article discusses the misperceptions that have resulted in an overprescription of beta-blockers, which in all likelihood have untoward effects on patients with HFpEF, even if they have atrial fibrillation or coronary artery disease as a comorbidity.

Beta-blockers in atrial fibrillation-trying to make sense of unsettling results.

Atrial fibrillation is closely associated with heart failure and adversely affects outcomes. Beta-blockers are strongly recommended to avoid rapid ventricular conduction and tachycardia-induced cardiomyopathy. In this Viewpoint article, we discuss an emerging body of evidence that questions beta-blockers as a preferred rate-control therapy in patients with atrial fibrillation.

Effect of Personalized Accelerated Pacing on Quality of Life, Physical Activity, and Atrial Fibrillation in Patients With Preclinical and Overt Heart Failure With Preserved Ejection Fraction: The myPACE Randomized Clinical Trial.

Importance: Patients with heart failure with preserved ejection fraction (HFpEF) with a pacemaker may benefit from a higher, more physiologic backup heart rate than the nominal 60 beats per minute (bpm) setting.

Objective: To assess the effects of a moderately accelerated personalized backup heart rate compared with 60 bpm (usual care) in patients with preexisting pacemaker systems that limit pacemaker-mediated dyssynchrony.

Design, Setting, And Participants: This blinded randomized clinical trial enrolled patients with stage B and C HFpEF from the University of Vermont Medical Center pacemaker clinic between June 2019 and November 2020.

Heart rate changes and myocardial sodium.

Historic studies with sodium ion (Na ) micropipettes and first-generation fluorescent probes suggested that an increase in heart rate results in higher intracellular Na -levels. Using a dual fluorescence indicator approach, we simultaneously assessed the dynamic changes in intracellular Na and calcium (Ca ) with measures of force development in isolated excitable myocardial strip preparations from rat and human left ventricular myocardium at different stimulation rates and modeled the Na -effects on the sodium-calcium exchanger (NCX). To gain further insight into the effects of heart rate on intracellular Na -regulation and sodium/potassium ATPase (NKA) function, Na , and potassium ion (K ) levels were assessed in the coronary effluent (CE) of paced human subjects.

Clinical impact of Bachmann's bundle pacing defined by electrocardiographic criteria on atrial arrhythmia outcomes.

Aims: Evaluate whether Bachmann's bundle pacing (BBp) defined by electrocardiographic (ECG) criteria is associated with less atrial fibrillation/tachycardia (AF/AT) compared with anatomically defined right atrial septal pacing (RASp) and right atrial appendage pacing (RAAp).

Methods And Results: This is a retrospective study comparing BBp with non-specific RASp and RAAp on new incidence, burden, and recurrence of AF/AT. We included patients who underwent atrial lead placement between 2006 and 2019 and received > 20% atrial pacing.

Personalized pacing for diastolic dysfunction and heart failure with preserved ejection fraction: Design and rationale for the PACE randomized controlled trial.

Background: Patients with pacemakers and heart failure with preserved ejection fraction (HFpEF) or isolated diastolic dysfunction (DD) may benefit from a higher backup heart rate (HR) setting compared with the standard setting of 60 bpm.

Objective: The purpose of this study was to assess the effects of a personalized backup HR setting (PACE group) compared with 60 bpm (control group).

Methods: In this prospective, blinded, randomized controlled study, pacemaker patients with DD or HFpEF and atrial pacing with intrinsic ventricular conduction or conduction system or biventricular pacing are randomized to the PACE group or control group for 1 year.

Heart Rate-Induced Myocardial Ca Retention and Left Ventricular Volume Loss in Patients With Heart Failure With Preserved Ejection Fraction.

Background Increases in heart rate are thought to result in incomplete left ventricular (LV) relaxation and elevated filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). Experimental studies in isolated human myocardium have suggested that incomplete relaxation is a result of cellular Ca overload caused by increased myocardial Na levels. We tested these heart rate paradigms in patients with HFpEF and referent controls without hypertension.

Premature ventricular contraction detection for long-term monitoring in an implantable cardiac monitor.

Background: Premature ventricular complexes (PVCs) are an important therapeutic target in symptomatic patients and in the setting of PVC-induced cardiomyopathy; however, measuring burden and therapeutic response is challenging. We developed and validated an algorithm for continuous long-term monitoring of PVC burden in an insertable cardiac monitor (ICM).

Methods: A high-specificity PVC detection algorithm was developed using real-world ICM data and validated using simultaneous Holter data and real-world ICM data.

Effects of a Higher Heart Rate on Quality of Life and Functional Capacity in Patients With Left Ventricular Diastolic Dysfunction.

There is no evidence-based treatment for heart failure with preserved ejection fraction. Although lower heart rates (HRs) provide an unequivocal benefit for patients with HF with reduced ejection fraction, higher HR might convey important hemodynamic and substrate-modifying benefits in patients with diastolic dysfunction. In a prospective study of 20 stable outpatients with diastolic dysfunction and pacemakers, we evaluated the effects of a 4-week increase in the lower pacemaker rate to 80 beats/min followed by reversal to the previous lower HR setting from weeks 4 to 6.

Troubleshooting and programming considerations for His bundle pacing.

Interest in permanent His bundle pacing as a means of both preventing pacing-induced cardiomyopathy and providing physiological resynchronization by normalization of His-Purkinje activation is steadily growing. However, there are differences in atrioventricular timing cycles, sensing, and tissue capture that distinguish His bundle pacing from right ventricular pacing, and hence it is of utmost importance to bear these differences in mind when implanting a His pacing lead and programming the His pacing system. This article focuses on critical considerations and troubleshooting options available to the implanter and follow-up clinic personnel.

Left Atrial Appendage Closure: A Safe and Effective Alternative to Anticoagulation?

To date, left atrial appendage closure (LAAC) devices continue to be assessed as an intuitive alternative to oral anticoagulant therapy to prevent embolic complications in patients with atrial fibrillation. Concerns remain about the up-front risks associated with device implantation as well as device efficacy in preventing embolic events as compared with anticoagulation. Currently, LAAC devices serve as a potential alternative to long-term anticoagulation with the benefit of decreased bleeding risk but with less protection against ischemic events.