Diagnostic Yield and Symptom–Rhythm Correlation of 24-Hour Holter Monitoring: A Cross-sectional Study

Abstract

Background: Twenty-four-hour ambulatory electrocardiography (Holter) is a cornerstone of non-invasive arrhythmia investigation. However, its diagnostic yield varies widely due to the sporadic nature of symptoms, creating challenges in clinical decision-making. Objective: This study aimed to evaluate the diagnostic yield of 24-hour Holter monitoring and analyse the electro-clinical correlation in patients presenting with palpitations, presyncope, or syncope at a tertiary care centre in Marrakech. Methods: We conducted a cross-sectional descriptive and analytical study on 140 consecutive patients (122 outpatients and 18 inpatients) at the Mohammed VI University Hospital, Marrakech, from September 2024 to June 2025. Indications were classified into three groups: Palpitations, Dizziness/Presyncope, and Syncope. Diagnostic yield was defined as the detection of an arrhythmia explaining the symptom or a major electrical anomaly requiring intervention. Statistical analysis was performed to correlate symptom types with arrhythmia mechanisms. Statistical analysis, utilising Pearson’s Chi-square and Fisher’s exact tests, was performed to correlate symptom types with arrhythmia mechanisms. Results: The mean age of the population was 52.6 ± 12.1 years, with a female predominance (57%). The overall diagnostic yield was 19.2% (27/140). Although 64.2% (90/140) of patients reported symptoms during the recording period, a positive electro-clinical correlation was established in only 30% (27/90) of these symptomatic patients. Palpitations were significantly associated with disorders of excitability (tachyarrhythmias) (P <.01), whereas dizziness/presyncope was strongly predictive of conduction disorders (bradyarrhythmias) (P <.01). Incidental findings, such as asymptomatic high-grade atrioventricular block, were detected in 2.9% of patients. Conclusion: The 24-hour Holter monitor provides a diagnostic yield of approximately 20% in our practice. Its major utility lies in excluding rhythmic causes during reported symptoms, thereby offering significant reassurance value. The strong statistical association between symptom type and arrhythmia mechanism aids in clinical stratification. However, negative examinations in high-risk patients, particularly those with syncope, warrant prolonged monitoring strategies.