Randomized assessment of syncope trial.
نویسندگان
چکیده
To the Editor: The recent article published in Circulation by Krahn et al1 underlines the usefulness of implantable loop recorders in the investigation of unexplained syncope. Patients with unexplained syncope were randomized to a “conventional” investigation strategy or to a “prolonged monitoring” strategy with an implantable loop recorder, with the latter strategy yielding a higher diagnostic rate. The conventional investigation strategy did not include, however, carotid sinus massage (CSM) in supine or erect positions as part of the protocol. CSM is a safe, simple procedure2 that takes little time if added to a head-up tilt protocol such as that used by the authors and yields a diagnosis in up to 30% of older patients with unexplained syncope.3 It consequently forms an integral part of our standard investigative protocol in patients with unexplained syncope. Considering the age profile of the groups studied (mean age 64 years), a diagnosis of cardioinhibitory carotid sinus syndrome could satisfactorily explain the extra diagnoses of bradycardia-induced syncope uncovered by the implantable loop recorder. Such diagnoses could potentially have been revealed by the addition of supine and erect CSM to the conventional investigation protocol without the need to resort to an invasive procedure. In addition, CSM may also have revealed vasodepressor or mixed carotid sinus syndrome in a proportion of the patients, thereby increasing the diagnostic rate. CSM, of course, would not have yielded the tachyarrhythmia and epilepsy diagnoses unmasked by the implantable loop recorder, but the main conclusion of the article relates to bradyarrhythmias in patients with unexplained syncope. Although the authors reported no adverse events after implantation of the loop recorders, implantation is nevertheless more expensive, more invasive, more time consuming, and has possibly more associated risks than the performance of CSM. We feel, therefore, that to verify the important conclusion of the article the study needs to be repeated with the inclusion of supine and erect CSM as part of the conventional investigation strategy.
منابع مشابه
Pacemaker therapy for prevention of syncope in patients with recurrent severe vasovagal syncope: Second Vasovagal Pacemaker Study (VPS II): a randomized trial.
CONTEXT Three previous small randomized trials have reported that pacemaker therapy is beneficial for patients with severe recurrent vasovagal syncope. However, because these trials were not double blind, they may have been biased in their assessment of outcomes and had a placebo effect of surgery. OBJECTIVE To determine if pacing therapy reduces the risk of syncope in patients with vasovagal...
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AIMS Recently, some studies revealed the efficacy of pacemaker implantation in decreasing recurrences in patients with vasovagal syncope. As these studies were not blinded or placebo-controlled, the benefits observed might have been due to a bias in the assessment of outcomes or to a placebo effect of the pacemaker. We performed a randomized, double-blind, placebo-controlled study in order to a...
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متن کاملTreatment of Unexplained Syncope A Multicenter, Randomized Trial of Cardiac Pacing Guided by Adenosine 5 -Triphosphate Testing
متن کامل
Benefit of dual-chamber pacing with Closed Loop Stimulation in tilt-induced cardio-inhibitory reflex syncope (BIOSync trial): study protocol for a randomized controlled trial
BACKGROUND The efficacy of dual-chamber cardiac pacing in neuro-mediated reflex syncope with a cardio-inhibitory response to the Tilt-Table test (TT) has not been definitively assessed so far. The lack of reproducibility of results from previous studies may be partially explained by discrepancies in subject selection and some weaknesses in design and methods. The European Society of Cardiology ...
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عنوان ژورنال:
- Circulation
دوره 105 2 شماره
صفحات -
تاریخ انتشار 2002