US emergency department visits for supraventricular tachycardia, 1993-2003

Background: Supraventricular tachycardia (SVT) is often described as a recurrent condition that leads to emergency department (ED) visits. However, the epidemiology of ED visits for SVT is unknown. Objectives: To define the frequency of SVT in U.S. EDs and to analyze patient characteristics, ED management, and disposition for such visits. Methods: The authors analyzed data from the National Hospital Ambulatory Medical Care Survey, 19932003. SVT cases were identified by using the International Classification of Diseases, Ninth Revision, Clinical Modification codes 426.7 or 427.0 in any of the three diagnostic fields. Results: Of the 1.1 billion ED visits over the 11-year study period, an estimated 555,000 (0.05%; 95% confidence interval [CI] = 0.04% to 0.06%) were related to SVT. The annual frequency and population rate appear stable between 1993 and 2003 (p for trend = 0.35). Compared with non-SVT visits, those with SVT were more likely to be older than 65 years of age (26% vs. 15%, p < 0.01) and female (70% vs. 53%, p < 0.01). Electrocardiograms were documented for most visits (91 %; 95% CI = 85% to 96%). Approximately half of the patients (51 %; 95% CI = 40% to 61 %) received an atrioventricular nodal blocking medication, most frequently adenosine (26%; 95% CI = 17% to 36%). SVT visits ended in hospital admission for 24% (95% CI = 15% to 34%). At the other extreme, 44% (95% CI = 32% to 56%) were discharged without planned follow-up. Conclusions: Supraventricular tachycardia accounts for approximately 50,000 ED visits each year. Higher visit rates in older adults and female patients are consistent with prior studies of SVT in the general population. This study provides an epiderniologic foundation that will enable future research to assess and improve clinical management strategies of SVT in the ED.