Implication of ventricular pacing burden and atrial pacing therapies on the progression of atrial fibrillation: A systematic review and meta-analysis of randomized controlled trials

Closed loop stimulation reduces the incidence of atrial high-rate episodes compared with conventional rate-adaptive pacing in patients with sinus node dysfunctions

AIMS

Subclinical atrial fibrillation (AF) is associated with increased risk of progression to clinical AF, stroke, and cardiovascular death. We hypothesized that in pacemaker patients requiring dual-chamber rate-adaptive (DDDR) pacing, closed loop stimulation (CLS) integrated into the circulatory control system through intra-cardiac impedance monitoring would reduce the occurrence of atrial high-rate episodes (AHREs) compared with conventional DDDR pacing.

METHODS AND RESULTS

Patients with sinus node dysfunctions (SNDs) and an implanted pacemaker or defibrillator were randomly allocated to dual-chamber CLS (n = 612) or accelerometer-based DDDR pacing (n = 598) and followed for 3 years. The primary endpoint was time to the composite endpoint of the first AHRE lasting ≥6 min, stroke, or transient ischaemic attack (TIA). All AHREs were independently adjudicated using intra-cardiac electrograms. The incidence of the primary endpoint was lower in the CLS arm (50.6%) than in the DDDR arm (55.7%), primarily due to the reduction in AHREs lasting between 6 h and 7 days. Unadjusted site-stratified hazard ratio (HR) for CLS vs. DDDR was 0.84 [95% confidence interval (CI), 0.72-0.99; P = 0.035]. After adjusting for CHA2DS2-VASc score, the HR remained 0.84 (95% CI, 0.71-0.99; P = 0.033). In subgroup analyses of AHRE incidence, the incremental benefit of CLS was greatest in patients without atrioventricular block (HR, 0.77; P = 0.008) and in patients without AF history (HR, 0.73; P = 0.009). The contribution of stroke/TIA to the primary endpoint (1.3%) was low and not statistically different between study arms.

CONCLUSION

Dual-chamber CLS in patients with SND is associated with a significantly lower AHRE incidence than conventional DDDR pacing.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Assessment of the efficacy of the electrocardiographic P-wave peak time in predicting atrial high rate episode in patients with cardiac implantable electronic devices

INTRODUCTION & OBJECTIVE

The incidence of atrial high-rate episode (AHRE) is high among patients with cardiac implantable electronic devices (CIEDs). In this context, the objective of this study is to evaluate the efficacies of P-wave indices (PWIs) obtained from the surface electrocardiography (ECG) in predicting future AHRE development.

MATERIAL & METHOD

The study sample consisted of 158 patients with CIEDs. The study group was divided into two subgroups according to the presence of AHRE during device interrogation. PWIs were calculated using the surface ECG.

RESULTS

There was no significant difference between the groups in the P-wave indices (PWIs), i.e., minimum P-wave duration (PWDmin), maximum P-wave duration (PWDmax) and P-wave dispersion (PWDIS). On the other hand, P-wave peak time in V1 lead (PWTV1) and P-wave peak time in D2 lead (PWPTD2) were significantly higher in the AHRE group than in the non-AHRE group.

CONCLUSION

The study findings revealed that novel ECG parameters PWPTV1 and PWPTD2 had high prognostic value in predicting patients likely to develop AHRE.

Electrocardiographic interpretation of pacemaker algorithms enabling minimal ventricular pacing

Cardiac pacing from the apex of the right ventricle has been shown to result in left ventricular dysfunction, atrial fibrillation, and increased mortality. To counter these effects, one of the strategies developed is avoidance of ventricular pacing when not necessary, using programmable algorithms to minimize ventricular pacing. Seven algorithms are available from 5 manufacturers. Four of the manufacturers have mode conversion algorithms that pace AAI(R) but, in the presence of failed atrioventricular (AV) conduction, demonstrate algorithm-offset and convert to DDD(R) with ventricular pacing. Three manufacturers do not have mode conversion but rather AV extension to encourage AV conduction. Each of these algorithms has a unique design and, when ventricular pacing is present, will regularly schedule conduction testing to encourage AV conduction and hence algorithm-onset. All of these algorithms seem to violate the rule of AV conduction by allowing the AV delay for sensed ventricular events to be longer than for ventricular paced events. The result is frequently bizarre electrocardiographic (ECG) appearances that often are unique to the company's algorithm but also suggest pacemaker malfunction. This review highlights and illustrates the features of these algorithms as they appear on ECG, and discusses other situations that result in unintended ventricular pacing.