Diagnostic Yield of Patient-activated Loop Recorders for Detecting Heart Rhythm Abnormalities in General Practice: a Randomised Clinical Trial

Background: Because palpitations and light headedness often occur paroxysmally these complaints are difficult to diagnose. The hazards for a GP are too many diagnostic interventions for worried well and too few diagnostics for potentially life threatening complaints.

Objectives: Patient-activated memo event recorders have proved to be successful in diagnosing episodes of cardiac arrythmias in secondary care. We tested the diagnostic yield of these devices in general practice.

Methods: A randomized clinical trial in general practice. Consecutive patients with complaints of palpitations or light-headedness were randomized to either usual care or usual care plus event-recorder. The main outcome was the difference in explained episodes. Secondary outcomes were the differences in the number and character of cardiac diagnoses and the feasibility of the event-recorder.

Results: There were fewer patients without a diagnosis in the intervention group (17% vs 38%; RR = 0.5, 95% CI 0.3 to 0.7) and more patients with a cardiac diagnosis (67% vs. 27%: RR 2.5, CI 1.8 to 3,5). More relevant cardiac arrhythmias were detected (22% vs 7%) with event recording than with usual care (RR 3.2, 95% CI 1.5 to 6.8).

Conclusion: Patient-activated loop recorders are feasible and effective diagnostic tools in patients with palpitations or light-headedness in primary care. More research into patient characteristics and selection criteria is needed to fine-tune the use of these devices in primary care.