Objective: To compare the diagnostic yield and cost-effectiveness of transtelephonic event monitors with those of Holter monitoring in patients with intermittent palpitations.
Design: Randomized crossover trial.
Setting: Diagnostic service of a teaching hospital and surrounding primary care practices.
Patients: 43 patients with previously uninvestigated palpitations who were referred for Holter monitoring.
Measurements: Patients were randomly allocated to receive an event monitor or 48-hour Holter monitor and then to receive the other device. Event monitors were used for 3 months or until two recordings were obtained while symptoms occurred. The main end point was an electrogram recorded during symptoms. The incremental cost-effectiveness of obtaining a diagnostic rhythm strip from event monitors was compared with that of Holter monitoring.
Results: The mean (+/- SD) patient age was 45 +/- 19 years; 37 patients (88%) were women. Event monitors were twice as likely to provide a diagnostic rhythm strip electrocardiogram during symptoms as 48-hour Holter monitoring (29 patients [67%] and 15 patients [35%], respectively; P < 0.001). Event monitors detected 8 patients (19%) with clinically important arrhythmias (6 patients with supraventricular tachycardia and 2 with atrial fibrillation or flutter), whereas the Holter monitors detected no significant arrhythmia (P < 0.005). With the event monitors, most patients transmitted an electrocardiogram recording by 6 weeks. Event monitors were dominant and therefore more cost-effective than 48-hour Holter monitoring, resulting in a cost savings of $213 for each additional diagnostic rhythm strip obtained during symptoms.
Conclusions: Holter monitoring is a poor diagnostic test for intermittent palpitations. Event recorders provide better data and are more cost-effective.