Atrioventricular Nodal Ablation in Atrial Fibrillation

Pulmonary Vein Isolation or Pace & Ablate in Elderly Patients with Persistent Atrial Fibrillation (ABLATE versus PACE) - Rationale, Methods and Design

Age is a major risk-factor for atrial fibrillation (AF) and associated hospitalizations. With increasing emphasis on rhythm-control, pulmonary-vein isolation (PVI) is often suggested, even to elderly patients (≥75 years). Efficacy of PVI aiming at rhythm-control is limited in persistent AF. Pacemaker implantation with atrioventricular-node ablation may represent a reasonable alternative, with the aim of controlling symptoms and improving quality-of-life in elderly patients. In this investigator-initiated, randomized, multicenter trial, we test the hypothesis that pacemaker-implantation and atrioventricular-node (AVN) ablation provides superior symptom-control over PVI in elderly patients with symptomatic persistent AF, without any increase in adverse-event profile. In the "ABLATE versus PACE" (NCT04906668) prospective, open-label superiority trial 196 elderly patients with normal ejection fraction and symptomatic persistent AF despite guideline-indicated medical therapy, will be randomized to either cryoballoon-PVI (ABLATE) or dual-chamber pacemaker implantation with subsequent AVN ablation (PACE), and followed for a minimum of 12 months. The primary efficacy outcome is a composite endpoint of rehospitalization for atrial arrhythmia or cardiac decompensation/ heart failure, (outpatient) electrical cardioversion or upgrade to cardiac resynchronization therapy due to worsening of left-ventricular ejection fraction ≤35%. Secondary endpoints include death from any cause, stroke, quality of life or procedure-related complications. Sample-size is designed to achieve 80% power for the primary endpoint (two-tailed alpha of 5%). "ABLATE versus PACE" will determine whether pacemaker implantation and AVN ablation can improve symptom-control in elderly patients with persistent AF over PVI without increasing safety endpoints.

Atrial fibrillation: better symptom control with rate and rhythm management

Atrial fibrillation (AF) is often associated with limiting symptoms, and with significant impairment in quality of life. As such, treatment strategies aimed at symptom control form an important pillar of AF management. Such treatments include a wide variety of drugs and interventions, including, increasingly, catheter ablation. These strategies can be utilised either singly or in combination, to improve and restore quality of life for patients, and this review covers the current evidence base underpinning their use. In this Review, we discuss the pros and cons of rate vs. rhythm control, while offering practical tips to non-specialists on how to utilise various treatments and counsel patients about all relevant treatment options. These include antiarrhythmic and rate control medications, as well as interventions such as cardioversion, catheter ablation, and pace-and-ablate.

Pulmonary Vein Isolation in Elderly Patients ≥ 75 Years: A Propensity Score-Matched Analysis With Focus on Differences Among Atrial Fibrillation Types

BACKGROUND

Age is a major risk factor for development of atrial fibrillation (AF) and associated with increased recurrence rates in the setting of rhythm control. Current data tend to support catheter ablation in elderly patients, but uncertainties exist regarding efficacy and safety of ablation in elderly patients.

METHODS

This was a prospective single-centre observational study with propensity score matching (PSM) to investigate the influence of age on efficacy and safety of cryoballoon ablation (CBA) stratified by age (< 75 years vs ≥ 75 years) and AF phenotype (paroxysmal vs persistent). Primary efficacy endpoint was recurrence of atrial arrhythmia after a 90-day blanking period. Safety endpoints were death, stroke, or procedure-associated complications.

RESULTS

Consecutive patients (n = 953) underwent CBA for first-time AF ablation. Median follow-up was 18 months. By means of PSM, 268 matches were formed. At 1 year, primary efficacy endpoint occurred in 22.4% of young vs 33.2% of elderly patients, including both AF phenotypes (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.47-0.90; P = 0.01). AF relapse occurred in 19.7% of young vs 28.5% of elderly patients with paroxysmal (HR, 0.63; 95% CI, 0.40-0.99; P = 0.046) compared with 25.9% (30 of 116, young) vs 38.8% (45 of 116, elderly) patients with persistent AF (HR, 0.62; 95% CI, 0.39-0.97; P = 0.038). No difference was observed regarding the incidence of safety endpoints between young and elderly patients (P = 0.38).

CONCLUSIONS

CBA is associated with higher recurrence rates in elderly (≥ 75 years) than in younger patients, with highest recurrence rates in elderly patients with persistent AF.

Antiarrhythmic drugs for atrial fibrillation in the outpatient setting

With burgeoning evidence for early rhythm control in patients with atrial fibrillation (AF), the management of AF in the outpatient setting has become more challenging. The primary care clinician often serves as the frontline in the pharmacologic management of AF. Because of drug interactions and the risk of proarrhythmia, many clinicians remain hesitant about the initiation and chronic management of antiarrhythmic drug prescriptions. However, with the likely increased use of antiarrhythmics for early rhythm control, understanding and familiarity with these medications have likewise become more important, especially since patients with AF probably have other non-cardiac medical conditions that can impact their antiarrhythmic therapy. In this comprehensive review, we provide informative, high-yield cases and edifying references that will help primary care providers become comfortable handling various clinical scenarios.

Current Data and Future Perspectives on Patients with Atrial Fibrillation and Cancer

Atrial fibrillation (AF) is an increasingly recognized comorbidity in patients with cancer. Indeed, cancer patients have a significantly higher incidence of AF than that observed in the general population. A reciprocal relationship between these two diseases has been observed, as much as some assume AF to be a marker for occult cancer screening, especially in older adults. The pathophysiological mechanisms are many and varied, including the underlying pro-inflammatory state, specific treatments (chemo- and radiotherapy), and surgery. The therapeutic management of patients with cancer and AF involves the same rhythm and frequency control strategies as the general population; however, the numerous interactions with chemotherapeutics, which lead to a significant increase in side effects, as well as the extreme fragility of the patient, should be considered. Anticoagulant therapy is also a complex challenge to address, as bleeding and stroke risk scores have not been fully assessed in this subpopulation. Furthermore, in large studies establishing the efficacy of direct oral anticoagulants (DOACs), cancer patients have been underrepresented. In this review, we elaborate on the mechanisms linking AF to cancer patients with a particular focus on the therapeutic challenges in this population.

His-bundle pacing and atrioventricular nodal ablation for noncontrolled atrial arrhythmia: A technical challenge with major clinical benefits

BACKGROUND

His-bundle pacing (HBP) is an appealing alternative to right ventricular pacing in patients referred for permanent ventricular pacing and atrioventricular nodal ablation (AVNA) because it preserves physiological ventricular activation. Only limited data regarding HBP combined with AVNA are available in the literature.

OBJECTIVE

The purpose of this study was to provide further evidence on the feasibility and efficacy of this therapeutic approach in patients with uncontrolled atrial arrhythmia.

METHODS

We prospectively included all patients who had undergone AVNA after HBP in 3 different hospitals between 2017 and 2022.

RESULTS

AVNA following HBP lead implantation was performed in 75 patients. Complete atrioventricular (AV) block was obtained in 58 patients (77%), and significant modulation of AV nodal conduction (heart rate <60 bpm) was obtained in 12 patients (16%). AVNA failure was observed in 5 patients (7%). Recording of an atrial signal by the HBP lead was more frequently observed in patients with AVNA modulation/failure than in patients with complete AV block (11/17 vs 5/58; P <.001). No lead dislodgment occurred during the AVNA procedures. Acute His-bundle (HB) capture threshold increase >1 V occurred in 11 patients (15%), with return to baseline value on day 1 in 9 patients. New York Heart Association functional class and left ventricular ejection fraction significantly improved from baseline to last follow-up (3.0 ± 0.7 vs 1.6 ± 0.5; P <.001; and 47% ± 14% vs 60% ± 9%; P <.0001, respectively).

CONCLUSION

AVNA combined with HBP for noncontrolled atrial arrhythmia was feasible and clinically efficient. Implanting the HB lead on the ventricular aspect of the tricuspid annulus avoiding atrial signal recording can facilitate AVNA.

An aggressive solution for patients with heart failure and atrial fibrillation: nodal ablation and cardiac resynchronization therapy

Heart failure and atrial fibrillation are two diseases that often coexist and contribute to worsening the prognosis and quality of life of patients. Managing this situation is still a challenge today. The ablation of the atrioventricular node associated with cardiac resynchronization therapy (CRT) fits into this context as a definitive but effective solution. Indeed, long-term positive results have been demonstrated in patients with atrial fibrillation ineligible for ablation and refractory to medical therapy in terms of symptom reduction and, more recently, also mortality. Furthermore, the role of this strategy in obtaining adequate biventricular pacing in patients who may benefit from CRT but are ineligible due to the presence of atrial fibrillation is being highlighted.

Persistent Atrial Fibrillation in Elderly Patients: Limited Efficacy of Pulmonary Vein Isolation

(1) Background: Cryoballoon pulmonary vein isolation (cryoPVI) is established for symptomatic paroxysmal atrial fibrillation (AF) treatment, but its value in persistent AF is less clear. In particular, limited data are available on its efficacy in elderly patients (≥75 years) with persistent AF. Age is an important modifier of AF progression and represents a risk-factor for AF recurrence. (2) Methods: Prospective, single-center observational study to evaluate the impact of age on efficacy and safety of cryoPVI in elderly patients. Primary efficacy endpoint was symptomatic AF recurrence after 90-day blanking period. Primary safety endpoints were death from any cause, procedure-associated complications or stroke/transient ischemic attack. Median follow-up was 17 months (range 3−24). (3) Results: We included 268 patients with persistent AF (94 ≥ 75 years of age). Multivariate Cox regression analysis identified age as the only independent factor influencing AF recurrence in the overall cohort (p = 0.006). To minimize confounding bias in efficacy and safety analysis of cryoPVI, we matched younger and elderly patients with respect to baseline characteristics. At 24 months, primary efficacy endpoint occurred in 13/69 patients <75 years and 31/69 patients ≥75 years of age (24 months Kaplan−Meier event-rate estimates, HR 0.34; 95% CI, 0.19 to 0.62; log-rank p = 0.0004). No differences were observed in the occurrence of safety end points. (4) Conclusions: Elderly (≥75 years) patients with persistent AF undergoing cryoPVI had an approximately threefold higher risk of symptomatic AF recurrence than matched younger patients. Accordingly, other treatment modalities may be evaluated in this population.

Predictive values of left ventricular mechanical dyssynchrony for CRT response in heart failure patients with different pathophysiology

BACKGROUND

Cardiac resynchronization therapy (CRT) patients with different pathophysiology may influence mechanical dyssynchrony and get different ventricular resynchronization and clinical outcomes.

METHODS

Ninety-two dilated cardiomyopathy (DCM) and fifty ischemic cardiomyopathy (ICM) patients with gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) were included in this retrospective study. Patients were classified based on the concordance between the left ventricular (LV) lead and the latest contraction or relaxation position. If the LV lead was located on or adjacent to both the latest contraction and relaxation position, the patient was categorized into the both match group; if the LV lead was located on or adjacent to the latest contraction or relaxation position, the patient was classified into the one match group; if the LV lead was located on or adjacent to neither the latest contraction nor relaxation position, the patient was categorized to the neither group. CRT response was defined as [Formula: see text] improvement of LV ejection fraction at the 6-month follow-up. Variables with P < .05 in the univariate analysis were included in the stepwise multivariate model.

RESULTS

During the follow-up period, 58.7% (54 of 92) for DCM patients and 54% (27 of 50) for ICM patients were CRT responders. The univariate analysis and stepwise multivariate analysis showed that QRS duration, systolic phase bandwidth (PBW), diastolic PBW, diastolic phase histogram standard deviation (PSD), and left ventricular mechanical dyssynchrony (LVMD) concordance were independent predictors of CRT response in DCM patients; diabetes mellitus and left ventricular end-systolic volume were significantly associated with CRT response in ICM patients. The intra-group comparison revealed that the CRT response rate was significantly different in the both match group of DCM (N = 18, 94%) and ICM (N = 24, 62%) patients (P = .016). However, there was no significant difference between DCM and ICM in the one match and neither group. For the inter-group comparison, Kruskal-Wallis H-test revealed that CRT response was significantly different in all the groups of DCM patients (P < .001), but not in ICM patients (P = .383).

CONCLUSIONS

Compared with ICM patients, systolic PBW, diastolic PBW and PSD have better predictive and prognostic values for the CRT response in DCM patients. Placing the LV lead in or adjacent to the latest contraction and relaxation position can improve the clinical outcomes of DCM patients, but it does not apply to ICM patients.

Atrioventricular node ablation and pacing for atrial tachyarrhythmias: A meta-analysis of postoperative outcomes

BACKGROUND

Atrioventricular node ablation (AVNA) and pacemaker (PM) is performed in symptomatic atrial fibrillation (AF) unresponsive to medical treatment and percutaneous ablation. This meta-analysis evaluated results after AVNA and PM.

METHODS

Primary and secondary endpoints were early/late overall/cardiac-related mortality and early/late postoperative complications. Meta-regression explored mortality and preoperative characteristics relation.

RESULTS

We selected 93 studies with 11,340 patients: 9105 right ventricular (RV)-PM, and 2235 biventricular PM (cardiac resynchronization therapy, CRT). Malignant arrhythmia (2.5%), heart failure (2.4%), and lead dislodgement (2.0%) were most common periprocedural complications. Pooled estimated 30-day mortality was 1.08% (95%CI:0.65-1.77). At 19.9 months median follow-up (IQR: 10.3-34 months), rehospitalization (0.79%/month) and heart failure (0.48%/month) were the most frequent complications. Overall mortality incidence rate (IR) was 0.43%/month (95%CI:0.36-0.51), and cardiac death IR 0.27%/month (95%CI:0.22-0.32). No mortality determinants emerged in the AVNA CRT subgroup. AVNA RV-PM subgroup univariable meta-regression showed inverse relationship between age, ejection fraction (EF), and late cardiac death (Beta = -0.0709 ± 0.0272; p = 0.0092 and Beta = -0.0833 ± 0.0249; p = 0.0008). Coronary artery disease (CAD) was directly associated to follow-up overall/cardiac mortality at univariable (Beta = 0.0550 ± 0.0136, p < 0.0001; Beta = 0.0540 ± 0.0130, p < 0.0001) and multivariable (Beta = 0.0460 ± 0.0189, p = 0.152; Beta = 0.0378 ± 0.0192, p = 0.0491) meta-regression.

CONCLUSIONS

Solid long-term evidence supporting AVNA and pace is lacking. Younger patients with reduced LVEF% have increased follow-up cardiac mortality after AVNA RV and may require CRT. Alternative strategies to maintain sinus rhythm and ventricular synchronism should be compared to AVNA to support future treatment strategies.

Prevalence and Impact of Atrial Fibrillation on Intra-Hospital Mortality in Patients Aged ≥75 Years

It is unclear whether the association between atrial fibrillation (AF) and intra-hospital mortality in patients aged 75 years and older is causal or not. This study aims (1) to describe the prevalence and clinical characteristics of AF in ≥75-year-old inpatients and (2) to study the association between AF and length of stay (LOS) and intra-hospital mortality. This retrospective cohort study includes consecutive patients aged ≥75 years admitted between January 2017 and December 2019 to a Belgian secondary hospital. Survival analysis was conducted on the whole dataset and a propensity score-matched dataset separately. Propensity score matching (PSM) was performed to account for the individual probability of having AF given a set of covariates. In 9,105 patients, 3,137 (34%) had a diagnosis of AF upon hospital admission. AF prevalence increased with age strata (from 29% to 38%), and Charlson Co-morbidity Index (from 28% to 57%). Intra-hospital mortality (20%) was higher in the AF group than in the AF-free group (25% vs 17%, p <0.001). The median LOS was 11 days and was shorter in those without AF (10 [4, 17] days) compared with those with AF (11 [5, 19], p <0.001). After PSM, AF was not associated with increased odds of LOS >10 days (odds ratio 1.08, confidence interval: 0.98 to 1.20, p = 0.13). The risk of intra-hospital death for patients with AF remained higher compared with those without AF (log-rank p = 0.0015 and hazard ratio 1.17; confidence interval: 1.04 to 1.32, p = 0.008). In conclusion, the prevalence of AF was high (34%) in inpatients aged ≥75 years and increased with age and co-morbidity burden. After PSM, patients with AF had a 17% higher risk of intra-hospital mortality than patients without AF.

ESC-Leitlinien 2021 zur Herzschrittmacher- und kardialen Resynchronisationstherapie – Systemwahl

Die neuen ESC-Leitlinien haben gegenüber den vorherigen Leitlinien die Systematik teilweise verändert, kommen aber bei den herkömmlichen Schrittmacherindikationen und der hieraus abgeleiteten Systemwahl zu vergleichbaren Ergebnissen. Als Standardoption wird bei allen Patienten ohne Vorhofflimmern ein Zweikammer-Schrittmacher (DDD) empfohlen. Dabei wird gefordert, durch ein AV-Management (AVM) die ventrikuläre Impulsabgabe möglichst zu minimieren. Bei den erweiterten Indikationen im Bereich der AV-Blockierungen und Reizleitungsstörungen entsteht dagegen durch die stärkere Berücksichtigung der kardialen Resynchronisationstherapie (CRT) und der Neuaufnahme der His-Bündel-Stimulation (HBP) ein sehr viel komplexeres Bild der Therapiemöglichkeiten. Bei Patienten mit Herzinsuffizienz und eingeschränkter LV-Funktion (HFrEF) wird bei verbreitertem QRS-Komplex (> 130 ms), vor allem bei Linksschenkelblock-Morphologie, die Implantation eines CRT-Systems empfohlen. Erstmals wurde die His-Bündel-Stimulation für Patienten, bei denen eine Koronarsinuselektrode nicht erfolgreich zu platzieren ist, und für Patienten mit einer LVEF > 40% und über 20% ventrikuläre Stimulation in die Leitlinien aufgenommen.

Atrial fibrillation in older adults with cancer

Cancer and atrial fibrillation (AF) are common co-morbid conditions in older adults. Both cancer and cancer treatment increase the risk of developing new AF which increases morbidity and mortality. Heart rate and rhythm control along with anticoagulation therapy remain the mainstay of treatment of AF in older adults with both cancer and AF. Adjustments to the treatment may be necessary because of drug interactions with concurrent chemotherapy. Cancer and old age increase the risk of both, thromboembolism and bleeding. The risk of these complications is further enhanced by concomitant cancer therapy, frailty, poor nutrition status and, coexisting geriatric syndromes. Therefore, careful attention needs to be given to the risks and benefits of using anticoagulant medications. This review focuses on the management of AF in older patients with cancer, including at the end-of-life care.

Pacemaker and Atrioventricular Junction Ablation in Patients With Atrial Fibrillation—A Systematic Review of Systematic Review and Meta-Analysis

Background

Cardiac resynchronization therapy (CRT) could be considered for heart failure (HF) patients with atrial fibrillation (AF) unless a potent ventricular capture strategy is conducted. However, the benefit of a pacemaker (PM; as part of CRT) in patients with AF and whether atrioventricular junction (or nodal) ablation (AVAB) can improve the prognosis of these patients compared with those treated medically to support ventricular capture are unclear.

Methods and Results

Systematic reviews and meta-analyses investigating the roles of PMs and AVAB in patients with AF were obtained in a search of the PubMed, Embase, and Medline databases and then analyzed with respect to the following outcomes: mortality, left ventricular ejection fraction, and clinical findings including the New York Heart Association class, 6-min walk distance (6MWD), quality of life as assessed in a specific questionnaire, and response to CRT. The quality of the included reviews was assessed using the Assessing the Methodological Quality of Systematic Reviews 2 tool, which includes 16 items. This study was finally based on 13 systematic reviews or meta-analyses. The results showed that patients with AF have higher all-cause mortality rates compared with patients with sinus rhythm and that AVAB can reduce all-cause mortality in patients with AF. Although the functional improvement was better in sinus rhythm than in patients with AF, in the latter, AVAB increased the 6MWD and reduced the CRT nonresponse rate in patients with AF.

Conclusion

Atrial fibrillation is associated with a higher all-cause mortality rate in patients with CRT implantation. AVAB, by increasing the 6MWD and survival, can improve the prognosis of these patients.

Rate control strategies for atrial fibrillation

Atrial fibrillation (AF) is one of the main cardiac arrhythmias associated with higher risk of cardiovascular morbidity and mortality. AF can cause adverse symptoms and reduced quality of life. One of the strategies for the management of AF is rate control, which can modulate ventricle rate, alleviate adverse associated symptoms and improve the quality of life. As primary management of AF through rate control or rhythm is a topic under debate, the purpose of this review is to explore the rationale for the rate control approach in managing AF by considering the guidelines, recommendations and determinants for the choice of rate control drugs, including beta blockers, digoxin and non- dihydropyridine calcium channel blockers for patients with AF and other comorbidities and atrioventricular nodal ablation and pacing. Despite the limitations of rate control treatment, which may not be effective in preventing disease progression or in reducing symptoms in highly symptomatic patients, it is widely used for almost all patients with atrial fibrillation. Although rate control is one of the first line management of all patient with atrial fibrillation, several issues remain debateable.

Analysis of the ESC/EACTS 2020 Atrial Fibrillation Guidelines With Perioperative Implications

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia worldwide, with an individual lifetime risk of approximately 37% in the United States. Broadly defined as a supraventricular tachyarrhythmia with disorganized atrial activation, AF results in an increased risk of stroke, heart failure, valvular heart disease, and impaired quality of life, and confers a significant burden on the health of individuals and society. AF in the perioperative setting is common and a significant source of perioperative morbidity and mortality worldwide. The latest iteration of the European Society of Cardiology AF guidelines published in 2020 provide the clinician a valuable road map for the management of this arrythmia. This expert review will comprehensively analyze the 2020 European Society of Cardiology guidelines and provide perioperative management tools for the clinician.

Effectiveness and safety of AV node ablation after His bundle pacing in patients with uncontrolled atrial arrhythmias

INTRODUCTION

In patients with uncontrolled atrial fibrillation, atrioventricular (AV) node ablation after permanent His bundle pacing (p-HBP) could be a therapeutic option for heart rate (HR) control. We aimed to demonstrate the advantages of AV node ablation with p-HBP, and to describe its effectiveness and safety.

METHODS

This descriptive observational study included patients with uncontrolled permanent atrial arrhythmias who were candidates for HR control (January 2019 to July 2020) and underwent p-HBP and AV node ablation.

RESULTS

A total of 39 patients were included. The median left ventricular ejection fraction (LVEF) was 55% (45-60); 46.1% in NYHA class II and 43.6% in NYHA class III. p-HBP was achieved in 92.3% (n = 36), and AV node ablation was successfully performed in all patients. The LVEF improved in patients with reduced LVEF (baseline, 35% [23.8-45.3%]; follow-up, 40% [35-56.5%], p < 0.05); the NYHA class also showed improvement (baseline, 71.4% patients in class III and 7.1% in class II, and at follow-up, 78.6% patients in class II and 14.3% in class I). In patients with previously normal LVEF, LVEF remained stable; nevertheless, a significant NYHA class improvement was observed (baseline, 63.6% class II and 31.8% class III patients; follow-up, 54.5% class I and 45.5% class II patients). The His thresholds and lead parameter values did not significantly change during the follow-up and remained stable.

CONCLUSIONS

In patients with uncontrolled atrial arrhythmias who underwent AV node ablation after p-HBP, the NYHA class improved and the LVEF increased in those with reduced baseline LVEF. The values of pacing parameters were acceptable and remained stable during the follow-up.

The 2020 Canadian Cardiovascular Society/Canadian Heart Rhythm Society Comprehensive Guidelines for the Management of Atrial Fibrillation

The Canadian Cardiovascular Society (CCS) atrial fibrillation (AF) guidelines program was developed to aid clinicians in the management of these complex patients, as well as to provide direction to policy makers and health care systems regarding related issues. The most recent comprehensive CCS AF guidelines update was published in 2010. Since then, periodic updates were published dealing with rapidly changing areas. However, since 2010 a large number of developments had accumulated in a wide range of areas, motivating the committee to complete a thorough guideline review. The 2020 iteration of the CCS AF guidelines represents a comprehensive renewal that integrates, updates, and replaces the past decade of guidelines, recommendations, and practical tips. It is intended to be used by practicing clinicians across all disciplines who care for patients with AF. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) system was used to evaluate recommendation strength and the quality of evidence. Areas of focus include: AF classification and definitions, epidemiology, pathophysiology, clinical evaluation, screening and opportunistic AF detection, detection and management of modifiable risk factors, integrated approach to AF management, stroke prevention, arrhythmia management, sex differences, and AF in special populations. Extensive use is made of tables and figures to synthesize important material and present key concepts. This document should be an important aid for knowledge translation and a tool to help improve clinical management of this important and challenging arrhythmia.

A case report of simultaneous His pacemaker implantation and atrioventricular junction ablation following unsuccessful treatment of atrial fibrillation

BACKGROUND

Atrial fibrillation can contribute to heart failure. Frequently, rhythm control is unachievable. Atrioventricular (AV) junction ablation and pacemaker implantation remain to be a therapeutic option for rate control in atrial fibrillation. Interventricular asynchrony is a potential downside of right ventricular pacing. However, cardiac resynchronization therapy and His pacing restore physiological activation sequences of the ventricles.

CASE SUMMARY

The reported patient had undergone several interventions to cure atrial fibrillation without sufficient rhythm control and experienced deleterious effects of recurrent arrhythmias. Finally, we decided to ablate the AV junction simultaneously with the implantation of a His bundle pacemaker. Atrioventricular junction ablation had to be repeated following conduction recurrence. A left-sided transaortic approach was required to create a permanent effect and to avoid distal lesions. His pacing was not affected by the AV junction ablation at all. The pre-existing widened QRS was normalized by His pacing, the patient became free of any complaints with full restoration of exertion capability.

DISCUSSION

His pacing has the potential to contribute to a revival of the 'ablate-and-pace' concept for incurable atrial fibrillation by restoring physiological ventricular activation, thereby overcoming the particular drawbacks of continuous ventricular pacing. Atrioventricular junction ablation simultaneously with the pacemaker implantation procedure is safe and feasible. His pacing is at least an alternative for cardiac resynchronization therapy. The implantation procedure is sometimes challenging.

Drivers of hospitalization in atrial fibrillation: A contemporary review

Atrial fibrillation (AF)-related hospitalization has risen over the last 2 decades and is the most influential determinant of total disease-related expenditure. In this review article, we describe several identified drivers of hospitalization from several registries and large-scale clinical trials, including key cardiovascular and non-traditional risk factors. We also discuss available assessment tools for discerning overall risk of hospitalization, including AF symptom scores, thrombosis and bleeding disposition, and non-invasive cardiac structural assessment. Finally, we highlight the different treatment paradigms that have been proven to reduce AF burden, progression, and hospitalization in the literature.

Nonpharmacological Treatment of Atrial Fibrillation: What Is the Role of Device Therapy?

Atrial fibrillation is the most common arrhythmia in the adult population, and its incidence and prevalence are still rising. Cardiac devices are widely used in clinical practice in the management of various rhythm disturbances and heart failure treatment. Many patients who receive a pacemaker, implantable cardioverter-defibrillator, or cardiac resynchronization therapy also experience atrial fibrillation in the course of their life. Therefore, this review aims to describe the role of these devices in the treatment and prevention of atrial fibrillation in the device recipients. In addition, all these implantable devices also serve as permanent ECG (electrocardiogram) monitors, thus providing important information about the presence and characteristics of atrial fibrillation that may or may not be detected by the patient but can modify our therapeutical approach with regard to the stroke prevention.

Ventricular fibrillation associated with Graves' disease and amiodarone induced thyrotoxicosis

This case involves a 55-year-old male patient with systolic heart failure and refractory atrial fibrillation due to thyrotoxicosis, who was electrically cardioverted but then developed torsade de pointes and ventricular fibrillation. Rate control was unsuccessful with digoxin, cardizem, labetalol, esmolol and amiodorone. Patient was externally cardioverted after which ECGs showed prolonged QT with frequent premature ventricular contractions. ECGs also showed 'R-on-T' phenomenon leading to torsades and ventricular fibrillation. Atrial overdrive pacing was used to terminate the dangerous arrhythmia and the patient returned to sinus rhythm. Interestingly, he was found to have new onset thyrotoxicosis and started on methimazole.

Arrhythmia-Induced Cardiomyopathy

BACKGROUND

Heart failure affects 1–2% of the population and is associated with elevated morbidity and mortality. Cardiac arrhythmias are often a result of heart failure, but they can cause left-ventricular systolic dysfunction (LVSD) as an arrhythmia-induced cardiomyopathy (AIC). This causal relationship should be borne in mind by the physician treating a patient with systolic heart failure in association with cardiac arrhythmia.

METHODS

This review is based on pertinent publications retrieved by a selective search in PubMed (1987–2017) and on the recommendations in current guidelines.

RESULTS

The key criterion for the diagnosis of an AIC is the demonstration of a persistent arrhythmia (including pathological tachycardia) together with an LVSD whose origin cannot be explained on any other basis. Nearly any type of tachyarrhythmia or frequent ventricular extrasystoles can lead, if persistent, to a progressively severe LVSD. The underlying pathophysiologic mechanisms are incompletely understood; the increased ventricular rate, asynchronous cardiac contractions, and neurohumoral activation all seem to play a role. The most common precipitating factors are supraventricular tachycardias in children and atrial fibrillation in adults. Recent studies have shown that the causal significance of atrial fibrillation in otherwise unexplained LVSD is underappreciated. The treatment of AIC consists primarily of the treatment of the underlying arrhythmia, generally with drugs such as beta-blockers and amiodarone. Depending on the type of arrhythmia, catheter ablation for long-term treatment should also be considered where appropriate. The diagnosis of AIC is considered to be well established when the LVSD normalizes or improves within a few weeks or months of the start of targeted treatment of the arrhythmia.

CONCLUSION

An AIC is potentially reversible. The timely recognition of this condition and the appropriate treatment of the underlying arrhythmia can substantially improve patient outcomes.

Prediction and Management of Recurrences after Catheter Ablation in Atrial Fibrillation and Heart Failure

Catheter ablation is recommended in patients with symptomatic atrial fibrillation (AF) refractory to pharmacologic therapy. AF recurrence is common postablation, particularly in patients with heart failure, because of multiple structural and functional changes that can occur. Determining predictors of AF recurrence has become increasingly important. These include increased left atrial volume, termination of AF during the index ablation, electrocardiogram parameters, and serum biomarkers. Cardiac MRI can also determine the degree of scarring and left atrial sphericity, which is used in risk prediction scores. In patients with recurrence, further treatment options include pharmacologic therapy and atrioventricular nodal ablation with pacing.

Atrial Fibrillation and Heart Failure: Untangling a Modern Gordian Knot

Heart failure (HF) and atrial fibrillation (AF) share common risk factors and frequently coexist. Both are highly prevalent in our aging population, and mortality associated with the combination is significantly higher than for each alone. An intricate link exists between AF and HF, including interrelated mechanisms and pathophysiology. Asymptomatic left ventricular systolic or diastolic dysfunction can exacerbate or be exacerbated by AF, resulting in HF with reduced ejection fraction or preserved ejection fraction. A number of treatment strategies have improved symptoms, exercise tolerance, and quality of life for patients with HF, but few have resulted in alteration in prognosis. Sinus rhythm, achieved pharmacologically, has not altered important outcomes, including cardiovascular or total mortality in patients with HF. In recent studies, catheter ablation to achieve sinus rhythm seems to have a significant impact on symptoms, heart function, and possibly mortality. Until future studies can confirm or clarify the impact of catheter ablation on outcomes, the field remains cautious but optimistic that better treatment strategies for patients with HF with reduced ejection fraction or preserved ejection fraction are within reach.

Pharmacological Therapy for Rate and Rhythm Control for Atrial Fibrillation in 2017

In spite of the emergence of non-pharmacological approaches, medical therapy remains the primary modality of treatment for most patients with atrial fibrillation (AF). This review will look at evidence for rate and rhythm control approaches, and at factors that would help in choosing the appropriate treatment strategy for individual patients.

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Zusammenfassung. Zusammenfassung: Das Vorhofflimmern ist die häufigste supraventrikuläre Rhythmusstörung und entwickelt sich typischerweise bei Patienten mit kardiovaskulären Risikofaktoren oder einer zugrunde liegenden Kardiopathie. Die Bandbreite an Symptomen ist sehr weit und reicht von vollkommen asymptomatischen Patienten bis zur schweren Herzinsuffizienz. Eine korrekte Dokumentation mittels EKG ist unabdingbar für die Diagnose. Für jeden Patienten mit Vorhofflimmern ist eine komplette internistisch-kardiologische Abklärung indiziert. Von zentraler Bedeutung in der Behandlung ist die Thromboembolie-Prophylaxe bei Patienten mit einem erhöhten Risiko für einen Schlaganfall, dies unabhängig von der übrigen Therapie des Vorhofflimmerns. Beim Letzteren ist neben der antiarrhythmischen Therapie die Kontrolle der kardiovaskulären Risikofaktoren sowie die Behandlung einer allfällig vorhandenen Herzinsuffizienz entscheidend. Neben der medikamentösen Rhythmuskontrolle hat sich die Ablationsbehandlung als effektive und sichere alternative Therapieoption etabliert.

Sudden death and its risk factors after atrioventricular junction ablation and pacemaker implantation in patients with atrial fibrillation

BACKGROUND

Although sudden death (SD) is a rare complication after atrioventricular junction (AVJ) ablation and permanent pacemaker implantation, the risk factors leading to this SD remain unknown. The purpose of this study was to investigate SD and its risk factors after ablate-and-pace strategy for rate control in atrial fibrillation (AF) patients during long-term follow-up.

HYPOTHESIS

METHODS: From January 2005 to December 2009, we enrolled into this study 517 AF patients with AVJ ablation and right ventricular pacemaker implantation. Patients were divided into 2 groups, SD and non-SD. Cox proportional hazards models were used to assess potential risk factors for overall mortality and SD.

RESULTS

During a mean follow-up of 25.8 ± 18.6 months (range, 3 days to 63.8 months), 53 patients died (15 with SD). Cox proportional hazards models showed that the presence of congestive heart failure, New York Heart Association functional class, chronic renal failure, and nonsustained ventricular tachycardia were risk factors that predicted overall mortality. For SD, the presence of dilated cardiomyopathy and mitral stenosis were associated risk factors. SD was exclusively seen in patients who had narrow QRS complex or right bundle branch block prior to AVJ ablation and pacemaker implantation; SD was not seen in any patient with preexisting complete left bundle branch block.

CONCLUSIONS

Dilated cardiomyopathy, mitral stenosis, and baseline QRS morphology should be examined as potential risk factors for SD after AVJ ablation and pacemaker implantation.