Clinical investigationDetection of asymptomatic arrhythmias in unexplained syncope☆
Section snippets
Patients
Patients referred to the Arrhythmia Service at the University of Western Ontario for investigation of syncope with a left ventricular ejection fraction >35% were approached to participate in a prospective trial assessing the benefit of automatic detection loop recorders in patients with unexplained syncope and preserved left ventricular function. Consecutive patients were approached to participate in the trial when they had recurrent unexplained syncope or a single episode of syncope associated
Results
Sixty patients with unexplained syncope were enrolled in the trial (Table I). All patients underwent echocardiography and 24 hours of ECG monitoring before enrollment to confirm eligibility. The outcome of patients during the 1-year monitoring period is summarized in Figure 1. Symptoms recurred in 30 patients (50%) during the 1-year follow-up period. Eleven of these patients experienced borderline asymptomatic arrhythmias before their symptomatic episode (see below). Sinus node disease with
Discussion
Prolonged monitoring of patients with unexplained syncope with an autodetect implantable loop demonstrated frequent asymptomatic arrhythmias. These “subthreshold” arrhythmias did not result in symptoms that came to clinical attention, but were sufficiently marked that they could not be ignored in the context of unexplained syncope. Pre-specified asymptomatic arrhythmias developed in 15% of patients, leading to treatment decisions that resulted in resolution of syncope. We chose marked
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Cited by (67)
Bradycardia risk stratification with implantable loop recorder after unexplained syncope
2024, Archives of Cardiovascular DiseasesAn ensemble of features based deep learning neural network for reduction of inappropriate atrial fibrillation detection in implantable cardiac monitors
2023, Heart Rhythm O2Citation Excerpt :Subcutaneous implantable cardiac monitors (ICMs) have been used for automatic detection of cardiac arrhythmias and patient symptom–triggered storage of loop-recorded recent electrocardiograms (ECGs).1,2 ICMs have been used for diagnosing the cause of unexplained syncope,3,4 for monitoring of recurrent atrial fibrillation (AF) after ablation of AF,5 and in patients with history of cryptogenic stroke.6 In most of these cases, the main objective is to deliver therapeutic interventions to patients in a timely manner to reduce clinical morbidity associated with these clinical conditions in a safe and cost efficient manner.4
Prediction of Pacemaker Requirement in Patients With Unexplained Syncope: The DROP Score
2022, Heart Lung and CirculationCitation Excerpt :Both patients with identifiable cardiac causes of syncope and those with syncope of unknown cause are at increased risk of mortality [5]. Up to 20% of patients with implantable loop recorders (ILR) for unexplained syncope require subsequent permanent pacemaker (PPM) insertion for bradyarrhythmia [6]. While ILRs are frequently inserted for further diagnostic evaluation, they are costly and are unable to prevent further syncopal episodes.
Real-World Incidence of Pacemaker and Defibrillator Implantation Following Diagnostic Monitoring With an Insertable Cardiac Monitor
2019, American Journal of CardiologyHolding Area LINQ Trial (HALT)
2017, Indian Pacing and Electrophysiology JournalCitation Excerpt :These devices have been traditionally implanted in a hospital setting, utilizing resources traditionally reserved for invasive cardiac device implants such as implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT) devices. While these invasive cardiac device implants have inherent need for an advanced level of anesthesia and transvenous leads along with fluoroscopy, ICMs are minimally invasive and require only a small subcutaneous incision of approximately 1 cm in length [6–9]. Because the sensing electrodes are self-contained on the surface of the device, these devices do not require cardiac leads, facilitating the possibility of transitioning the procedure to an outpatient setting [10] such as in the office, clinic setting or holding area of an operating, electrophysiology, or catheterization lab.
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Supported by a grant from the Heart and Stroke Foundation of Ontario (NA3397). Dr Krahn is a research scholar of the Heart and Stroke Foundation of Canada.