Atrial Fibrillation Monitoring in Cryptogenic Stroke: the Gaps Between Evidence and Practice

Abstract

Identifying occult paroxysmal atrial fibrillation as the etiology of cryptogenic stroke has been a top research priority in the past decade. This is because prompt initiation of anticoagulation has significantly decreased subsequent stroke risk. Available evidence suggests that prolonged cardiac monitoring after stroke increases the likelihood of detecting atrial fibrillation. However, further research is required to fill in the gaps in regard to the optimal period of monitoring, candidates for monitoring, etc. Here, we review the current evidence supporting the use of prolonged monitoring for cryptogenic stroke patients and discuss the directions of future research.

Prevalence and risk factors of ischaemic stroke in the young: a regional Australian perspective

“…Recent data estimate that cardioembolic strokes account for 20–30% and cryptogenic mechanisms are responsible for 30–40% of ischaemic strokes across all ages . However, using extended cardiac monitoring, up to 9.2% of cryptogenic strokes can be re‐classified as due to atrial fibrillation, a major cause of cardioembolism . We posit that the high number of cardioembolic strokes in our population is due to our routine practice of prolonged inpatient telemetry (72 h or more) and outpatient Holter monitoring.…”

How and When to Screen for Atrial Fibrillation after Stroke: Insights from Insertable Cardiac Monitoring Devices

“…The detection of AF on cardiac monitoring does not prove causality and while in the majority of situations it could represent the etiology of the stroke, alternative explanations and stroke mechanisms may occur [ 32 ]. Occult AF may be an incidental finding in a population that shares many common risk factors with ischemic stroke [ 33 ]. Alternatively, it has been postulated that AF may be the consequence of certain types of stroke [ 31 ].…”

“…Of course, the decision to continue monitoring also depends on the treatment implication of finding AF. It is agreed to investigate only CS patients where the risk-benefit balance would favor the initiation of anticoagulation if AF would be identified [ 7 , 33 ].…”

Atrial fibrillation and cryptogenic stroke. What is the current evidence? Role of electrocardiographic monitoring

“…It should also be noted that there is a clear benefit in the use of anticoagulants in patients with ischemic stroke or prior transient ischemic attacks in whom AF is demonstrated. In this case, the decision of anticoagulation is based on the implementation of the CHA2DS2‐VASc score, even if the mechanistic basis of this result is not entirely clear …”

“…In this case, the decision of anticoagulation is based on the implementation of the CHA2DS2-VASc score, even if the mechanistic basis of this result is not entirely clear. 9 Prolonged ECG recordings identify patients with low AF burden (<1% of the monitoring time). 10 This type of AF has a low risk of stroke albeit higher than that of patients without AF.…”