scholarly journals Heart Failure Differentially Modulates Natural (Sinoatrial Node) and Ectopic (Pulmonary Veins) Pacemakers: Mechanism and Therapeutic Implication for Atrial Fibrillation

2019 ◽  
Vol 20 (13) ◽  
pp. 3224 ◽  
Author(s):  
Chao-Shun Chan ◽  
Yung-Kuo Lin ◽  
Yao-Chang Chen ◽  
Yen-Yu Lu ◽  
Shih-Ann Chen ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Electrical Activity ◽  
Sinoatrial Node ◽  
Sick Sinus Syndrome ◽  
Pulmonary Veins ◽  
Calcium Handling ◽  
Adrenergic Stimulation ◽  
Therapeutic Implications ◽  
Cardiac Filling

Heart failure (HF) frequently coexists with atrial fibrillation (AF) and dysfunction of the sinoatrial node (SAN), the natural pacemaker. HF is associated with chronic adrenergic stimulation, neurohormonal activation, abnormal intracellular calcium handling, elevated cardiac filling pressure and atrial stretch, and fibrosis. Pulmonary veins (PVs), which are the points of onset of ectopic electrical activity, are the most crucial AF triggers. A crosstalk between the SAN and PVs determines PV arrhythmogenesis. HF has different effects on SAN and PV electrophysiological characteristics, which critically modulate the development of AF and sick sinus syndrome. This review provides updates to improve our current understanding of the effects of HF in the electrical activity of the SAN and PVs as well as therapeutic implications for AF.

Heart Failure Differentially Modulates the Effects of Ivabradine on the Electrical Activity of the Sinoatrial Node and Pulmonary Veins

2018 ◽  
Vol 24 (11) ◽  
pp. 763-772 ◽  
Author(s):  
Chao-Shun Chan ◽  
Yao-Chang Chen ◽  
Shih-Lin Chang ◽  
Yung-Kuo Lin ◽  
Yu-Hsun Kao ◽  
...  
Keyword(s):  
Heart Failure ◽  
Electrical Activity ◽  
Sinoatrial Node ◽  
Pulmonary Veins

scholarly journals Catheter Ablation in the Treatment of Atrial Fibrillation

2020 ◽  
Vol 29 (02) ◽  
pp. 108-112 ◽  
Author(s):  
Aaron B. Hesselson
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Catheter Ablation ◽  
Pulmonary Vein ◽  
Pulmonary Veins ◽  
Combined Approach ◽  
Esophageal Fistula ◽  
Pulmonary Vein Reconnection

AbstractCatheter ablation (CA) of the pulmonary veins for atrial fibrillation (AF) is growing exponentially and is the most commonly performed electrophysiologic procedure. Initial descriptions focused on CA for paroxysmal AF, and now more recently expanded in application to persistent AF and those with comorbid heart failure. Efforts to improve success have and continue to address issues such as pulmonary vein “reconnection” following ablation through different ablative energy modalities, and the use of a “hybrid” surgical/endocardial combined approach in persistent forms of AF. Technologic advances as well are concurrently seeking to improve safety, particularly regarding the incidence of atrio-esophageal fistula in this seemingly ever-growing ablation population.

scholarly journals Profibrotic, Electrical, and Calcium-Handling Remodeling of the Atria in Heart Failure Patients With and Without Atrial Fibrillation

2018 ◽  
Vol 9 ◽  
Author(s):  
Cristina E. Molina ◽  
Issam H. Abu-Taha ◽  
Qiongling Wang ◽  
Elena Roselló-Díez ◽  
Marcus Kamler ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Calcium Handling ◽  
Heart Failure Patients

scholarly journals Risk of sick sinus syndrome in patients diagnosed with atrial fibrillation: a population-based cohort

2021 ◽  
Author(s):  
Pil-Sung Yang ◽  
Daehoon Kim ◽  
Eunsun Jang ◽  
Hee Tae Yu ◽  
Tae-Hoon Kim ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Elderly Population ◽  
Sick Sinus Syndrome ◽  
Sinus Node ◽  
Pacemaker Implantation ◽  
Population Based ◽  
Av Block ◽  
Increased Risk ◽  
Observation Period

Background: Sinoatrial node dysfunction and atrial fibrillation (AF) frequently coexist and interact with each other, often to initiate and perpetuate each other. Objective: To determine the effect of AF on the incidence and risk of sick sinus syndrome (SSS). Methods: The association of incident AF with the development of incident SSS was assessed from 2004 to 2013 in 302,229 SSS- and pacemaker-free participants aged ≥60 years in the Korea National Health Insurance Service-Senior cohort. Results: During an observation period of 1,854,800 person-years, incident AF was observed in a total of 12,797 participants (0.69%/year). The incidence of SSS was 0.2 and 3.4 per 1000 person-years in the incident AF and the propensity score matched no-AF groups, respectively. After adjustment, the risk of SSS caused by incident AF was significantly increased, with a hazard ratio (HR) of 13.4 (95% confidence interval [CI]: 8.4–21.4). This finding was consistently observed after censoring for heart failure (HR, 16.0; 95% CI: 9.2–28.0) or heart failure/myocardial infarction (HR, 16.6; 95% CI: 9.3-29.7). Incident AF also was associated with an increased risk of pacemaker implantation related with both SSS (HR, 21.8; 95% CI: 8.7–18.4) and atrioventricular (AV) block (HR, 9.5; 95% CI: 4.9–18.4). These results were consistent regardless of sex and comorbidities. Conclusion: Incident AF was associated with more than ten times increased risk of SSS in an elderly population regardless of comorbidities. Risk of pacemaker implantations related with both sinus node dysfunction and AV block were increased in elderly population with incident AF.

P322Understanding the multiple P-wave morphologies in paroxysmal atrial fibrillation, during sinus rhythm, using computer simulation

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
D Filos ◽  
D Tachmatzidis ◽  
C Bakogiannis ◽  
D Mouselimis ◽  
A Tsarouchas ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Sinus Rhythm ◽  
Electrical Activity ◽  
Pulmonary Veins ◽  
P Wave ◽  
Electrical Remodeling ◽  
Atrial Remodeling ◽  
P Waves ◽  
Sa Node ◽  
Atrial Activation

Abstract Background Atrial Fibrillation (AF) is the most common atrial arrhythmia. The initiation and perpetuation of AF are related to atrial remodeling affecting the electrical and structural atrial characteristics. The beat-to-beat analysis of the P-wave morphology (PWM), during sinus rhythm (SR), revealed the existence of a secondary PWM, while the proportion of the P-waves which follow the secondary morphology is higher in patients with a history of paroxysmal AF (pAF). This observation has led to the hypothesis that the multiple PWM may be the result of a transient shift in the stimulus origin, possibly within the broader anatomical region of the sinoatrial (SA) node, and it is the atrial electrical remodeling that contributes to more frequent P-waves following a secondary morphology in patients with pAF. Purpose To better understand the pathophysiology of AF there is a need to link different levels of analysis, in order to interpret macroscopic observations, through a surface electrocardiogram, with changes occurring at cell and tissue level. Towards this direction, computational modeling can be used as it is a non-invasive and reproducible method of analyzing the electrical activity of the heart. Methods The CRN atrial model was used, and a two-dimensional geometry of the atrial architecture was considered, including the major anatomical structures, like Crista Terminalis, Pectinate Muscles and Pulmonary Veins. Using existing knowledge, the CRN model was adapted to describe the ionic properties of the atrial structures as well as the electrical remodeling occurring under pAF conditions. Several scenarios were considered related to the extent of the electrical remodeled tissue and Heart Rate (HR) values. The stimulation protocol was designed as 5 stimuli originated at a specific point within the SA node area whereas the sixth stimulus originated either at the same location or 1 mm far from the previous one. The temporal variations of the atrial activation as a result of the transient shift of the sixth stimulus origin were computed. Results In electrically remodeled tissue, the displacement of the excitation site within the SA node resulted in a significant increase of the differences in atrial activation compared to healthy tissue, and the greater the spatial extent of the remodeling the greater the differences in the completion of the electrophysiological processes. In addition, increased HR or HR variability led to the increase of the differences especially when electrical remodeling coexists. Conclusions The observed differences in atrial substrate activation can explain the increased number of P-waves that match a secondary PWM in pAF patients during SR, while a future perspective is to use PWM as a marker to estimate the electrical remodeling extent in the atrial tissue. These results underline the need to link the macroscopic findings to the suspected microscopic electrical activity in order to better understand the pathophysiology of AF.

scholarly journals Research Priorities in Atrial Fibrillation Screening

Circulation ◽  
2021 ◽  
Vol 143 (4) ◽  
pp. 372-388
Author(s):  
Emelia J. Benjamin ◽  
Alan S. Go ◽  
Patrice Desvigne-Nickens ◽  
Christopher D. Anderson ◽  
Barbara Casadei ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Ischemic Stroke ◽  
Research Priorities ◽  
Critical Research ◽  
Therapeutic Implications ◽  
The Public ◽  
National Heart Lung

Clinically recognized atrial fibrillation (AF) is associated with higher risk of complications, including ischemic stroke, cognitive decline, heart failure, myocardial infarction, and death. It is increasingly recognized that AF frequently is undetected until complications such as stroke or heart failure occur. Hence, the public and clinicians have an intense interest in detecting AF earlier. However, the most appropriate strategies to detect undiagnosed AF (sometimes referred to as subclinical AF) and the prognostic and therapeutic implications of AF detected by screening are uncertain. Our report summarizes the National Heart, Lung, and Blood Institute’s virtual workshop focused on identifying key research priorities related to AF screening. Global experts reviewed major knowledge gaps and identified critical research priorities in the following areas: (1) role of opportunistic screening; (2) AF as a risk factor, risk marker, or both; (3) relationship between AF burden detected with long-term monitoring and outcomes/treatments; (4) designs of potential randomized trials of systematic AF screening with clinically relevant outcomes; and (5) role of AF screening after ischemic stroke. Our report aims to inform and catalyze AF screening research that will advance innovative, resource-efficient, and clinically relevant studies in diverse populations to improve the diagnosis, management, and prognosis of patients with undiagnosed AF.

scholarly journals Nitric Oxide and Mechano-Electrical Transduction in Cardiomyocytes

2020 ◽  
Vol 11 ◽  
Author(s):  
Hannah E. Boycott ◽  
My-Nhan Nguyen ◽  
Besarte Vrellaku ◽  
Katja Gehmlich ◽  
Paul Robinson
Keyword(s):  
Nitric Oxide ◽  
Heart Failure ◽  
Atrial Fibrillation ◽  
Heart Function ◽  
Calcium Handling ◽  
Nitric Oxide Production ◽  
Nitric Oxide Signaling ◽  
Oxide Production ◽  
Electrical Signaling

The ability§ of the heart to adapt to changes in the mechanical environment is critical for normal cardiac physiology. The role of nitric oxide is increasingly recognized as a mediator of mechanical signaling. Produced in the heart by nitric oxide synthases, nitric oxide affects almost all mechano-transduction pathways within the cardiomyocyte, with roles mediating mechano-sensing, mechano-electric feedback (via modulation of ion channel activity), and calcium handling. As more precise experimental techniques for applying mechanical stresses to cells are developed, the role of these forces in cardiomyocyte function can be further understood. Furthermore, specific inhibitors of different nitric oxide synthase isoforms are now available to elucidate the role of these enzymes in mediating mechano-electrical signaling. Understanding of the links between nitric oxide production and mechano-electrical signaling is incomplete, particularly whether mechanically sensitive ion channels are regulated by nitric oxide, and how this affects the cardiac action potential. This is of particular relevance to conditions such as atrial fibrillation and heart failure, in which nitric oxide production is reduced. Dysfunction of the nitric oxide/mechano-electrical signaling pathways are likely to be a feature of cardiac pathology (e.g., atrial fibrillation, cardiomyopathy, and heart failure) and a better understanding of the importance of nitric oxide signaling and its links to mechanical regulation of heart function may advance our understanding of these conditions.

scholarly journals Biology of the Sinus Node and its Disease

2015 ◽  
Vol 4 (1) ◽  
pp. 28 ◽  
Author(s):  
Moinuddin Choudhury ◽  
Mark R Boyett ◽  
Gwilym M Morris ◽  
◽  
◽  
...  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Endurance Exercise ◽  
Sinoatrial Node ◽  
Sinus Node ◽  
Current Evidence ◽  
Important Process ◽  
Age Related ◽  
Cell Atrophy

The sinoatrial node (SAN) is the normal pacemaker of the heart and SAN dysfunction (SND) is common, but until recently the pathophysiology was incompletely understood. It was usually attributed to idiopathic age-related fibrosis and cell atrophy or ischaemia. It is now evident that changes in the electrophysiology of the SAN, known as electrical remodelling, is an important process that has been demonstrated in SND associated with heart failure, ageing, diabetes, atrial fibrillation and endurance exercise. Furthermore, familial SND has been identified and mutations have been characterised in key pacemaker genes of the SAN. This review summarises the current evidence regarding SAN function and the pathophysiology of SND.

scholarly journals Clinical characteristics of patients with atrial flutter before radiofrequency ablation

2020 ◽  
Keyword(s):  
Heart Failure ◽  
Atrial Fibrillation ◽  
Radiofrequency Ablation ◽  
Chronic Heart Failure ◽  
Arterial Hypertension ◽  
Atrial Flutter ◽  
Stable Angina ◽  
Clinical Characteristics ◽  
Pulmonary Veins ◽  
Functional Classes

Introduction. Radiofrequency ablation (RFA) is today the method of choice for the ineffective medical treatment of atrial fibrillation (AF), but its course is often complicated by comorbid pathology. The predicted great impact of these nosologies on the effectiveness of radiofrequency ablation of the arrhythmia substrate requires additional study before RFA. Objectives – to analyze the clinical characteristics of patients with isolated atrial fibrillation and combination with of atrial fibrillation with atrial flutter (AF + AFib) that underwent radiofrequency ablation of the arrhythmia substrate. Materials and methods. 84 patients aged 65 ± 9 (82.3 % of men) were examined, who underwent RFA of the arrhythmia substrate: cavo-tricuspid isthmus (CTI) or combined with pulmonary veins isolation (CTI + PV) strategy for patients with AFib. Before radiofrequency ablation, the following clinical indicators were assessed: forms of AF + AFib, the presence of chronic heart failure (CHF) and functional classes (FC) according to NYHA classification, the forms of chronic coronary syndromes (CCS): postinfarction cardiosclerosis, syndrome-X, functional classes of stable angina (SA), stages of arterial hypertension (AH), the presence of type 2 diabetes or stroke in the anamnesis. Results. Radiofrequency ablation of isolated atrial fibrillation was more often performed for persistent arrhythmia in patients with stable angina III FC, arterial hypertension stage 2 and 3, radiofrequency ablation of combination of atrial fibrillation with atrial flutter – equally often for persistent or paroxysmal form in patients with SA I and II class, AH stage 2 and 3; in both cases patients with chronic heart failure II and III FC more often needed radiofrequency ablation of the arrhythmia substrate. Conclusions. Given the lack of correlation between clinical and demographic characteristics, it is advisable to continue studying their prognostic effect on the course of comorbid pathology and treatment of patients after radiofrequency ablation of the arrhythmia substrate of atrial fibrillation and combination of atrial fibrillation with atrial flutter.

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