1. From the AnMed Arrhythmia Specialists, Anderson, SC (J.A.M.); Duke Clinical Research Institute (L.K.S., L.T.), and Division of Cardiology (S.M.A.-K.), Duke University Medical Center, Durham, NC; and the St. Vincent Medical Group, Indianapolis, IN (R.I.F., B.P., D.R., R.V., L.W.G., K.G., E.N.P.).