Summary based on an article by Leonardo A. Orejarena, MD; Humberto Vidaillet, Jr., MD, FACC; Frank DeStefano, MD, MPH; David L. Nordstrom, PhD; Robert A. Vierkant, MAS; Peter N. Smith, MD, FACC; John J. Hayes, MD, FACC, originally published in the Journal of the American College of Cardiology, January, 1998, pages 150-157.)

Although substantial data exist regarding the epidemiology and significance of paroxysmal supraventricular tachycardia (PSVT) in otherwise healthy patients referred to specialized centers, nothing is published regarding these data points in the general population. By using the resources of the Marshfield Epidemiologic Study Area (MESA), the investigators from this study determined that patients with PSVT and the condition itself are different in the general population than in tertiary care centers.

MESA is composed of approximately 50,000 residents in and around Marshfield, Wisconsin. Because nearly all healthcare in this region is provided by two institutions, population-based epidemiological research can be efficiently conducted by means of a computerized diagnoses data base.

To evaluate PSVT in the general population, the entire population of MESA was considered at risk for development of PSVT. When adjusted by age and gender to reflect the general population of the United States, the data generated from MESA indicate that PSVT occurs in approximately 36/100,000 persons per year. By extrapolation, PSVT strikes nearly 89,000 new individuals per year, and there are approximately 570,000 persons overall with PSVT in the United States.

Unlike the mostly young, healthy patients reported from referrals, in the general population PSVT patients can be categorized as either individuals with other cardiovascular disease (about 54,000 new cases per year) or individuals with lone PSVT (about 35,000 new cases per year). Of interest, females in this study demonstrated a risk of developing PSVT two times greater than that of males. Also, subjects at least 65 years of age demonstrated a risk more than five times greater than that of younger residents. Additionally, patients with lone PSVT "...were younger (p=0.0002), had a faster PSVT heart rate (p=0.0006) and were more likely to have their condition first documented in the emergency room (69% vs. 30%, p=0.0377)." In females, symptoms were more likely to occur during childbearing years in patients with lone PSVT versus those with PSVT and other cardiovascular disease (58% vs. 9%, p=0.0272).

These investigators also assert that AV node reentry tachycardia (AVNRT) accounts for more than 60% of patients with PSVT undergoing invasive testing, and that AV reentry tachycardia (AVRT) accounts for about 30%. In the past, both AVNRT and AVRT have been considered as congenital anomalies. In contrast, the fact that 91% of males and only 50% of females with PSVT in this study experienced associated cardiovascular disease indicates that PSVT is a heterogeneous disease with different underlying mechanisms.

In summary, the investigators concluded that these data suggest "etiologic heterogeneity in the pathogenesis of PSVT and the need for more population-based research on this common condition."