Incremental diagnostic yield of loop electrocardiographic recorders in unexplained syncope

Area of Science:

• Cardiology
• Diagnostic Technology

Background:

• Syncope diagnosis remains challenging, with Holter monitoring often yielding non-diagnostic results (>90% of cases).
• Unexplained syncope necessitates advanced diagnostic tools to identify underlying cardiac arrhythmias or other causes.

Purpose of the Study:

• To evaluate the diagnostic impact of a cardiac loop electrocardiographic (ECG) recorder in patients with unexplained syncope after initial Holter monitoring.
• To assess the diagnostic yield and specific findings of the loop recorder in this patient cohort.

Main Methods:

• A prospective study involving 57 patients with unexplained syncope.
• Patients underwent a standardized evaluation protocol, including the use of a cardiac loop ECG recorder for up to 1 month.
• Analysis of recorded ECG data to identify arrhythmias or other cardiac events correlated with syncope episodes.

Main Results:

• The cardiac loop ECG recorder provided a definitive diagnosis in 14 out of 57 patients, yielding a diagnostic rate of 25% (95% CI: 14% to 38%).
• Diagnoses included ventricular tachycardia, high-grade atrioventricular block, supraventricular tachycardia, asystole/junctional bradycardia (neurally mediated syncope), and normal cardiac rhythms.
• No sudden cardiac death was observed in patients diagnosed with non-arrhythmic syncope by loop recording during follow-up.

Conclusions:

• Cardiac loop ECG recording is a valuable new diagnostic tool for syncope cases that remain unexplained after conventional Holter monitoring.
• This technology improves the diagnostic yield for identifying cardiac arrhythmias as a cause of syncope.
• The findings support the integration of loop recorders into the diagnostic pathway for unexplained syncope.