Detection of actionable arrhythmias in patients referred with syncope and collapse using mobile cardiac outpatient telemetry (MCOT)
N Sutlian, M Valkanas, A DunnAbstract
Background
The lifetime prevalence of syncope is approximately 40%, accounting for 1%-3% of emergency department (ED) visits, with nearly 50% of the patients requiring hospital admission.1,2 Current guidelines recommend external ambulatory cardiac monitoring for patients with unexplained syncope when there is a reasonable likelihood of identifying an arrhythmic cause and without high-risk features. Low- and intermediate-risk patients can be managed in the outpatient setting with ECG monitoring to identify rhythm-related causes while avoiding hospitalization. 2
Objective
Determine the diagnostic yield (DY) of actionable arrhythmias (AA) in patients referred for syncope and collapse prescribed ECG monitoring using the Philips MCOT.
Methods
A retrospective review was conducted of 37,406 patients aged ≥18 years with an ICD-10 diagnosis code of R55 (syncope and collapse) for data collected between January 1, 2021, and December 31, 2024. Data was analyzed by arrhythmia type, defined as either AA (met urgent and/or emergent criteria) or non-AA (did not meet urgent or emergent criteria), and stratified by prescription (Rx) length (0–2, 3–7, 8–14, >14 days). Length of Service (LoS) was defined as the number of days MCOT was worn. Urgent criteria were defined as Pause (≥3sec), Bradycardia (<35bpm for >30sec), Atrial Fibrillation/Flutter (AF/AFL, >10sec), Symptomatic Severe Tachycardia (>170bpm for >30sec), Asymptomatic Severe Tachycardia (>190bpm for >30sec), Ventricular Tachycardia (VT, >100bpm for >3 beats), and 2nd degree AV block (AVB). Emergent criteria were defined as Pause (≥10sec), Sustained VT (SVT, >150bpm for >30sec), Nonsustained VT (NSVT, >190bpm for >6 beats), and 3rd degree AVB.
Results
Patients were 56.2% Female and 43.8% Male, with an average age of 65.5 years. Rx length was grouped into 0-2 (n=93), 3-7 (n=3,015), 8-14 (n=7,610), and >14 days (n=26,688). Median (IQR) LoS were 1.0 (0.7, 1.5), 5.8 (4.6, 6.2), 12.6 (10.1, 13.1), and 27.1 (19.4, 28.9) days for the 0–2, 3–7, 8–14, and >14 days groups, respectively. The overall DY of all detected AA at 0-2, 3-7, 8-14, and >14 days was 4.3%, 10.5%, 15.1%, 20.6%, respectively (p<0.05; except for 0-2 vs 3-7 days p>0.5) (Figure 1). Longer monitoring duration led to higher detection rates of urgent and emergent events with significant increases in the detection of urgent arrhythmias (p<0.05; except for 0-2 vs 3-7 days p>0.5) (Figure 2). When AA were stratified by arrhythmia type, DY increased by 1 to 1.6-fold at 8-14 vs >14 days, 1.5 to 2-fold at 3-7 vs 8-14 days, and a 2 to 3-fold at 3-7 vs >14 days across AF/AFL, Bradycardia, AVB, and Pause.
Conclusion
In patients referred for ambulatory monitoring with syncope and collapse, the DY of AA increased significantly with increased Rx length. These findings suggest that low- and intermediate-risk patients may benefit from extended-duration ambulatory cardiac monitoring to improve arrhythmia detection and guide outpatient management.DY of Urgent and Emergent ArrhythmiasDetection of Actionable Arrhythmias