Yonsei Med J.  2013 May;54(3):590-595. 10.3349/ymj.2013.54.3.590.

Usefulness of an Implantable Loop Recorder in Patients with Syncope of an Unknown Cause

• Kang GH
• Oh JH
• Chun WJ
• Park YH
• Song BG
• Kim JS
• On YK
• Park SJ
• Huh J

• KMID: 1727869
• DOI: http://doi.org/10.3349/ymj.2013.54.3.590

Abstract

PURPOSE
The mechanisms underlying syncope remain unknown in about 20% of patients with recurrent syncope. The implantable loop recorder (ILR) has been shown to be a useful diagnostic tool in patients with unexplained syncope even after negative initial evaluations. Nevertheless, ILR has rarely been used in clinical practice.
MATERIALS AND METHODS
This study included 18 consecutive patients who had an ILR implanted at our center because of recurrent unexplained syncope after extensive diagnostic tests between February 2006 and June 2011.
RESULTS
Diagnosis was confirmed in 10 (55.6%) of the 18 enrolled patients (13 males, 61+/-15 years). The confirmed diagnoses included sick sinus syndrome (n=6, 60%), advanced atrioventricular block (n=2, 20%) and ventricular tachyarrhythmia (n=2, 20%). The mean follow-up durations of the total study subjects and the diagnosed patients were 11.3+/-10.6 months and 5.6+/-9.2 months, respectively. Of the 10 diagnosed patients, 8 (80%) were diagnosed within 6 months of loop recorder implantation.
CONCLUSION
ILR may be a valuable and effective diagnostic tool for patients with unexplained syncope.

Keyword

Implantable loop recorder; syncope

MeSH Terms

Adult
Aged
Electrocardiography/instrumentation/methods
Female
Humans
Male
Middle Aged
Monitoring, Physiologic/instrumentation/methods
Syncope/*diagnosis/etiology

Figure

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  Fig. 1 The proportion of finally diagnosed arrhythmias by ILR. SSS, sick sinus syndrome; AVB, atrio-ventricular block; VT, ventricular tachycardia; VF, ventricular fibrillation; ILR, implantable loop recorder.

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  Fig. 2 Cumulative diagnostic yields of arrhythmic causes of syncope after ILR implantation. ILR, implantable loop recorder.

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