A Study on Implantable Loop Recorders
Occult Atrial Fibrillation1 (AF), which increases the risk of secondary stroke, is commonly found in Asian cryptogenic stroke patients. Cardiologists are therefore exploring the use of Implantable Loop Recorders2 (ILRs) to remotely monitor cardiac activity and prevent the recurrence of stroke. Asst. Prof. Seow Swee-Chong presents his recent research study.
An Innovative Device
Stroke remains a major killer worldwide and is the fourth leading cause of death in Singapore. Patients with stroke also commonly present with occult AF and will need anticoagulation treatment to prevent secondary stroke.
The reason for the high incidence of occult AF among Asian cryptogenic stroke patients as well as the use of ILRs for AF diagnosis remains unclear.
Effectiveness of ILRs
To prove the effectiveness of ILRs, we conducted a trial on 71 patients with cryptogenic stroke between August 2014 and February 2017. Most of the patients were males (77.5%), aged 62 years (+/- 13.5 years). When AF episodes of more than two minutes were detected using proprietary algorithms, clinicians and patients would be alerted via remote monitoring. The AF episodes were then adjudicated using recorded electrograms and patients were counselled for anticoagulation treatment.
It was found that all AF episodes were asymptomatic and lasted an average of 77 minutes. Anticoagulation treatment was also initiated in all but one patient.
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By Asst. Prof. Seow Swee-Chong
1 Common arrhythmia which significantly increase stroke risk.
2 Small device implanted under the skin of the chest for cardiac monitoring.
3 A clinical prediction rule for estimating the risk of stroke in AF patients.
