Update on Bayés’ syndrome: the association between an interatrial block and supraventricular arrhythmias

ABSTRACT

Introduction: The past few years have given rise to extensive research on an interatrial block and its clinical relevance, mainly its association with supraventricular arrhythmias. In 2015, the authors of this article reviewed the Bayes syndrome for the first time and after three years there has been so much evidence accumulated that it seems reasonable to rewrite an update, based fundamentally on the new findings. Focused on its relationship with cardioembolic strokes, today efforts are being targeted at understanding its pathophysiology, its diagnosis, and its prognostic implications, in order to learn if it should be treated.

Areas covered: A non-systematic review of the literature was developed using the Pubmed and Cochrane databases, focusing on randomized clinical trials and large observational studies that evaluated new physiopathological and epidemiological aspects, new clinical scenarios in which it has been assessed and its association with dementia. Finally, those studies that proposed new possible treatments were reviewed.

Expert commentary: Interatrial block is not only a predictor of supraventricular arrhythmias, is a subclinical disease that might be considered as a marker of risk for adverse outcomes. Although there is some evidence to suggest that early treatment may be beneficial, potential therapies have yet to be investigated.

KEYWORDS:

• Atrial aberrancy
• atrial fibrillation
• atrial flutter
• Bachmann’s bundle
• Bayes’ syndrome
• interatrial block
• stroke
• supraventricular arrhythmia
• thromboembolism

Article highlights

• The substrate for the conduction delay between the right and left atria in the IAB is an electrical atrial remodeling that induces interatrial dyssynchrony, and electromechanical dysfunction that generates increased pressure, atrial dilatation, endothelial dysfunction, atrial fibrosis, and finally thrombogenic cascade.

• Atrial fibrosis, which is the anatomical substrate of IAB, can be detected by 3D speckle-tracking echocardiography measuring the LA strain and by 3D reconstruction of late gadolinium enhancement cardiovascular magnetic resonance. This is important because the amount of fibrosis is strongly associated with AF recurrence.

• IAB is common in patients with heart failure and these patients have more new-onset AF, ischemic stroke, hospitalizations, and higher mortality.

• In patients with valvular heart disease requiring surgery, advanced IAB was found to be independently associated with postoperative AF. In the same way, it has been demonstrated that post-TAVR new-onset AF is more frequent in IAB population.

• Many authors examined the association between IAB and stroke and found that IAB was independently associated with an increased risk of non-lacunar ischemic stroke and did not differ by sex, age or race, even without known AF. Furthermore, in centenarians, it predisposes to vascular dementia.

• In patients with high CHA2DS2-VASc score, IAB and thromboembolic complications, anticoagulant therapy could be initiated irrespective of documented AF.

This box summarizes key points contained in the article.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.