The diagnosis of atrial fibrillation in patients with cryptogenic stroke.
The use of ambulatory monitoring for the detection of atrial fibrillation in patients with cryptogenic stroke is a relatively new indication for this widely used electrocardiographic investigation.
In patients, and in particular the elderly, who present with a cerebrovascular accident of no known cause, referred to as a “cryptogenic stroke”, the most likely diagnosis is asymptomatic atrial fibrillation or flutter. How then do we diagnose this arrhythmia?
In many of the patients, a routine resting 12-lead electrocardiograph shows sinus rhythm, as the atrial fibrillation is paroxysmal, but episodes can still generate thrombi in the left atrial appendage, leading to an embolic stroke.
Although, there is low return, short-term Holter monitoring is generally the first line of investigation after an unhelpful ECG. Because the patient is asymptomatic, patient activated event monitoring has no role. There are, however, numerous medium-term event monitors available, which are widely used with varying results. They usually have specific atrial fibrillation software recognition algorithms and patients are monitored for one week to a month.
A major deficiency with most of these monitors is only one recording channel and artefact can be a problem. A two or three channel medium-term monitor with a sophisticated electrode patch is also available and has less artefact. What is clear and not surprising, the longer the period of monitoring, the more likely atrial fibrillation will be diagnosed and for that reason, multi-channel patch medium-term monitoring is recommended.
In 49+ years as a practicing cardiologist, Assoc Prof Harry Mond has published 260+ published manuscripts & books. A co-founder of Cardiac Monitoring Service, he remains Medical Director and oversees 500K+ heart studies each year.
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