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Cited by 360Cardiovascular Syncope and Autonomic DisordersCardiac electrophysiology and arrhythmiasHeart Rate Variability and Autonomic Control

Use of an Extended Monitoring Strategy in Patients With Problematic Syncope

Open access
Krahn, Andrew D., Klein, George J., Yee, Raymond, Takle-Newhouse, Teri, Norris, Caro·1999·Circulation
DOI 10.1161/01.cir.99.3.406
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Abstract

Background —The conventional investigation of patients who present with syncope involves short-term ECG monitoring or provocative testing with head-up tilt and electrophysiological testing. A symptom-rhythm correlation is often difficult to obtain during spontaneous syncope because of its sporadic, infrequent, and unpredictable nature. Methods and Results —We used a prolonged monitoring strategy to determine the cause of syncope in 85 patients (age, 59±18 years; 44 men) with recurrent undiagnosed syncope with an implantable loop recorder capable of cardiac monitoring for up to 18 months. During a mean of 10.5±4.0 months of follow-up, symptoms recurred in 58 patients (68%) 71±79 days (2.3±2.6 months) after implantable loop recorder insertion. An arrhythmia was detected in 42% of patients who recorded a rhythm during recurrent symptoms, with bradycardia present in 18 and tachycardia in 3. Five of the 18 bradycardic patients and 2 additional sinus rhythm patients received a clinical diagnosis of neurally mediated syncope. Patients who experienced presyncope were much less likely to record an arrhythmia during symptoms compared with recurrence of syncope (24% versus 70%, P =0.0005). There were no adverse events associated with recurrent symptoms, and there were no sudden deaths. Inability to freeze after an event occurred in 8 patients, and pocket infection occurred in 3. Conclusions —The strategy of prolonged monitoring is effective and safe in patients with problematic syncope.

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  • Implantable loop recorders improve care only in the subset of patients who are older, have asystole documented on the recorder, and had negative tilt test results, probably because many diagnoses are vasovagal syncope.

    “However, the devices have been shown to improve care in only the subset of patients who are older, have asystole documented on the ILR, and whose tilt test results were negative, probably because many of the diagnoses are of vasovagal syncope.”

    From 2015 Heart Rhythm Society Expert Consensus Statement on the Diagnosis and Treatment of Postural Tachycardia Syndrome, Inappropriate Sinus Tachycardia, and Vasovagal Syncope (2015) · cites this paper as [106]

    The Abstract (page not provided) concludes that prolonged monitoring was effective and safe in patients with problematic syncope, not only in the specified subset. The Symptom-Rhythm Correlation section (page not provided) reports diagnoses leading to pacemakers and treatment for tachyarrhythmias, but does not establish an older, recorder-documented-asystole, negative-tilt subgroup as the only patients whose care improved. It reports seven clinical diagnoses of neurally mediated syncope, not that many diagnoses were vasovagal. (LLM, conf=0.86)

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  • These patients appear to benefit from permanent pacing.

    “These patients appear to benefit from permanent pacing.105–112”

    From 2015 Heart Rhythm Society Expert Consensus Statement on the Diagnosis and Treatment of Postural Tachycardia Syndrome, Inappropriate Sinus Tachycardia, and Vasovagal Syncope (2015) · cites this paper as [106]

    The Symptom-Rhythm Correlation section reports that 12 of 18 patients with bradycardia during recurrent symptoms received pacemakers. It does not report whether pacing reduced subsequent syncope or otherwise benefited those patients; the study evaluated prolonged monitoring, not pacing outcomes. No page number is available in our copy. (LLM, conf=0.84)

    Experimental — accuracy not yet measured

  • The gold standard for the diagnosis of arrhythmic syncope is when there is a correlation between the symptoms and an ECG recording.

    “The gold standard for the diagnosis of arrhythmic syncope is when there is a correlation between the symptoms and an ECG recording. 195,196”

    From 2018 ESC Guidelines for the diagnosis and management of syncope (2018) · cites this paper as [196]

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Cites

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Research works printed but not linked: 1

  1. [9]9. Klein GJ, Gersh BJ, Yee R. Electrophysiologic testing: the final court of appeal for diagnosis of syncope? Circulation. 1995;92:1332-1335.

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Authors
Krahn, A. D., Klein, G. J., Yee, R., Takle-Newhouse, T., & Norris, C.
Affiliations
  • Western University (CA)
  • From the Division of Cardiology, University of Western Ontario, London, Ontario, Canada, and Medtronic, Minneapolis, Minn (T.T.-N.).
ORCID
Venue
Circulation
Publisher
Ovid Technologies (Wolters Kluwer Health)
Published
1999-01-26
Volume
99
Issue
3
Pages
406-410
ISSN
  • 0009-7322 (ISSN-L)
  • 1524-4539
DOI
10.1161/01.cir.99.3.406
OpenAlex
W2006949147
Semantic Scholar
23b308c400504de7e0f85483f49bf75ca93e86b0
Cited by
360
References
27
Citations by year
2026: 1 · 2025: 2 · 2024: 10 · 2023: 5 · 2022: 3 · 2021: 7 · 2020: 5 · 2019: 6 · 2018: 12 · 2017: 22 · 2016: 12 · 2015: 13 · 2014: 13 · 2013: 17 · 2012: 9
FWCI
24.90
Type
journal article
Language
en
Open access
Locations
  • Circulation (publishedVersion)
  • PubMed (publishedVersion)
Funders
Heart and Stroke Foundation of Canada
Topics
  • Health Sciences › Medicine › Surgery › Cardiovascular Syncope and Autonomic Disorders
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiac electrophysiology and arrhythmias
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Heart Rate Variability and Autonomic Control
Keywords
syncope, implantable loop recorder, prolonged cardiac monitoring, arrhythmia detection, neurally mediated syncope, bradycardia, tachycardia, presyncope, recurrent syncope
MeSH terms
Adult, Aged, Arrhythmias, Cardiac, Female, Humans, Male, Middle Aged, Recurrence, Syncope, Electrocardiography, Ambulatory, Tilt-Table Test, Prostheses and Implants

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