Cardiac event recorders yield more diagnoses and are more cost-effective than 48-hour Holter monitoring in patients with palpitations. A controlled clinical trial.

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.