Association of atrial tachyarrhythmias with atrial septal defect,Ebstein’s anomaly and Fontan patients

The number of adults with congenital heart disease is increasing as medical and surgical palliation for congenital heart lesions improves. With this comes long-term complications of congenital heart disease such as the increased risk of atrial tachyarrhythmias. Atrial septal defect, Ebstein’s anomaly and post-Fontan patient subsets are particularly important to focus on due to their unique characteristics and association with atrial tachyarrhythmias. Reviews, randomized controlled trials, and meta-analyses were obtained using electronic search strategies such as Medline and the Cochrane Library. References of electronically obtained studies were then used to obtain additional relevant studies. Sources were deemed relevant if they discussed the relationship between atrial septal defects/Ebstein’s anomaly/Fontan procedure and atrial tachyarrhythmias in respect to incidence, mechanism, recurrence or treatment. Selected sources were then stratified on the basis of quality. Patients in these subsets of congenital heart disease are at increased risk of atrial tachyarrhythmias for a variety of reasons when compared with the general population. It is necessary for pediatric and adult cardiologists alike to understand these differences, as well as their implications in diagnosis and management of such occurrences.     

Catheter ablation for asymptomatic atrial fibrillation?

Ablation therapy for atrial fibrillation (AF) has been shown to be more efficient than medical treatment alone. Long-term success of AF ablation is still around 50% after one ablation and higher after two, with a substantial amount of asymptomatic recurrences in formerly symptomatic patients. Given the lack of evidence for superiority of rhythm control over rate control in terms of stroke reduction and mortality, AF ablation remains a treatment for symptom reduction only, although ablation has never been a part of these studies. There is early evidence that ablation could decrease the long-term risk of stroke; however, prospective studies are needed to assess whether this is the case and how patients with a successful ablation can be identified. If AF ablation can be shown to improve long-term morbidity, it could also become a reasonable treatment for patients with asymptomatic AF.     

Rate or rhythm control in persistent atrial fibrillation?

Atrial fibrillation (AF) is the most common sustained tachyarrhythmia encountered in clinical practice, with the majority of patients aged > 65 years. With an increasingly ageing population, the burden of AF in society continues to rise. One of the principal controversies in AF management is whether to control the ventricular rate and accept the underlying rhythm, or to attempt to achieve sinus rhythm. Until recently there were no clinical trial data directly comparing a rate versus rhythm strategy, and most physicians have opted for rhythm control, based on its theoretical benefits. We present an up-to-date evidence-based overview of the relative merits of rate versus rhythm control in AF, including data from five recent randomized trials. We draw conclusions from these studies and present evidence-based guidance on when to adopt which approach in routine clinical practice.     

Treating atrial fibrillation. What is the consensus now?

Atrial fibrillation (AF) is a common cardiac arrhythmia, especially in elderly persons. Current recommendations outline pharmacologic and interventional therapies designed to minimize the risk of stroke and other morbidities that can accompany this condition. In this article, Drs Basu Ray and Heist review treatment options for cardioversion and control of rate and rhythm and make suggestions for best management in patients with chronic or intermittent AF.     

Should nursing home residents with atrial fibrillation be anticoagulated?

Most long-term care residents with atrial fibrillation would be at high risk for embolic stroke based on age and comorbidities according to the criteria presented here. Additionally, they are theoretically excellent candidates for adjusted-dose warfarin treatment for atrial fibrillation. They are accessible for monitoring and tend to have less dietary variability, a controlled medication list, and supervised medication administration. Balancing these features is at least a moderate risk of severe bleeding from anticoagulation based on age, comorbidities, and polypharmacy. However, studies suggest that even those long-term care residents identified as ideal candidates for anticoagulation may not receive warfarin. Those residents who do receive warfarin may not be anticoagulated within the therapeutic range much of the time. This treatment pattern may expose older adults with a high stroke risk to dying from a cardioembolic stroke or to acquiring functional deficits that make them more dependent and lower their quality of life.     

Right atrial ‘thrombus in transit’ and atrial septal defect in a 70-year-old man: cardioembolic source of pulmonary and paradoxical cerebral embolization

A 70-year-old man was admitted with sudden onset of dyspnea, near syncope and left hemiparesis. Clinical examination, blood gas analysis, ECG and the chest X-ray were consistent with pulmonary embolism. Transthoracic echocardiography (TTE) revealed right atrial free-floating thrombus, large atrial septal defect (ASD), right heart enlargement and pulmonary artery hypertension. Anticoagulation therapy was initiated immediately, soon after thrombolytic therapy was started but the patient died due to possible pulmonary or cerebral embolization. We underscore rapid diagnosis by TTE that revealed right heart thrombus in transit and large ASD.     

Cardioversion for atrial fibrillation – how to prevent thromboembolic complications?

Abstract

Cardioversion is an essential component of rhythm control strategy for atrial fibrillation. The thromboembolic risk of cardioversion is well established and the mechanisms behind the phenomenon have been comprehensively described. There are several clinical aspects that are important to take into consideration when assessing the safety of cardioversion. Before proceeding to cardioversion, the probability of early treatment failure and antiarrhythmic treatment options to prevent recurrences should be carefully evaluated to avoid the risks of repeated futile cardioversions. Effective periprocedural anticoagulation is the mainstay in thromboembolic complication prevention and the first week after rhythm conversion is the most vulnerable period in this respect. Early timing of cardioversion appears to be another important measure to decrease the risk of thromboembolic complications. Transoesophageal echocardiography is useful in clinical scenarios where early cardioversion is desirable due to debilitating clinical symptoms and a short duration of arrhythmia or the adequacy of preceding anticoagulation is uncertain. However, it does not lessen the need for effective anticoagulation after cardioversion. This review summarizes the recent scientific discoveries to improve the safety of cardioversion for atrial fibrillation.

• Key messages

• Cardioversion for atrial fibrillation entails a significant risk of thromboembolic complications, especially during the first week after the procedure.

• The intensity of periprocedural anticoagulation and the timing of cardioversion appear to be significant determinants of the risk of thromboembolism.

• Awareness of the clinical aspects influencing cardioversion safety should be raised.

     

Nibentan in arresting acute atrial fibrillation: risk or benefit?

AIM: To study efficacy and safety of using a domestic anti-arrhythmic drug nibentan for arresting acute atrial fibrillation. MATERIAL AND METHODS: A total of 210 patients received nibentan in a dose 0.125 mg/kg dissolved in 20.0 ml of 0.9% sodium chloride solution by intravenous slow jet 3-min injection. In no response, the injection was repeated 20 min later. Nibentan injection was accompanied with continuous ECG monitoring, measurements of QT interval, arterial pressure. The criterion of efficacy was atrial fibrillation conversion into the sinus rhythm within 24 hours after injection of a total nibentan dose. RESULTS: Nibentan in a dose 0.125 mg/kg demonstrated high efficacy (91.9%) and sufficient safety (incidence of polymorphic ventricular tachycardia 2.4%) including patients taking other antiarrhythmic drugs. A basic marker of an electrophysiological effect of nibentan on the myocardium is a dynamic change in the interval QT which may serve a predictor of sinus rhythm reestablishment (in QT > or =480 ms) and of a risk to develop proarrhythmogenic complications (in QT > or =640 ms).     

Gastroesophageal reflux and atrial fibrillation: is there any correlation?

Atrial fibrillation (AF), gastroesophageal reflux disease (GERD) and hiatal hernias are commonly seen in clinical practice. GERD and hiatal hernias have been proposed to be a possible cause of AF. In this paper, we will briefly review GERD, AF and hiatal hernias, consider the available literature covering the association between these diseases and provide further insight into the topic in general.     

Role of cardiac electronic implantable device in the stratification and management of embolic risk of silent atrial fibrillation: are all atrial fibrillations created equal?

Introduction: Ischemic strokes may be associated with atrial fibrillation (AF). AF detection is critical in ischemic stroke survivors, often recommending a switch from antiplatelet therapy to oral anticoagulants for secondary prevention.

Areas covered: Cardiac implantable electronic devices (CIED) with their long-term recording capability allows to document AF and to quantify the arrhythmia burden. Recent series in pacemaker and implantable cardioverter-defibrillator (ICD) recipients with no prior stroke showed that short episodes of AF increased stroke risk compared with those without AF recorded. Detection of AF by CIEDs represent a unique opportunity for promp prevention of embolic risk in silent AF. It will be attractive to identify AF before a stroke occurs.

Expert commentary: The purpose of this article is to review the role of CIED to detect AF, to quantify the role of AF burden, and to guide primary and secondary stroke prevention.     

How early is early enough to prevent stroke in atrial fibrillation?

Evaluation of: Healey JS, Connolly SJ, Gold MR et al. Subclinical atrial fibrillation and the risk of stroke. N. Engl. J. Med. 366(2), 120–129 (2012).

Atrial fibrillation (AF) is a potent risk factor for stroke, being responsible for 20% of ischemic strokes. Subclinical AF burden has received much attention, especially in the context of patients with cryptogenic strokes. However, little is known about the impact of subclinical episodes of rapid atrial rate and the primary risk of stroke and systemic embolism. Healey et al. investigated whether subclinical rapid atrial rate detected by implanted devices was associated with the risk of ischemic stroke in patients without clinical evidence of AF. The current article discusses the potential implications of the above results.