SVT RECURRENCE & CHRONIC THERAPY The rationale for chronic therapy in SVT is to prevent recurrences and to limit symptoms during recurrences [8]. SVT can be repetitive, but the recurrences are not readily predictable [11]. There is a wide range—from 0% to 78%—of reported recurrences of SVT, even with medical treatment [1, 2, 6, 19, 21]. There are several studies with reliable data (see Table 1 at end), but some reports of the predictors of recurrent episodes may include data that are not applicable to all patients and may involve invasive studies [21-23]. The physician attitude towards chronic therapy has also changed. While in Garson's 1981 study, chronic medication was started in only 72% of cases, our survey indicated that 98% of respondents would initiate chronic therapy [12]. This likely reflects the goal of minimizing morbidity and mortality in the care of all children with heart disease. In Garson's review, recurrences were common (56%) and most (75%) occurred within 3 months of the initial SVT presentation [6]. Perry et al. observed that, in 60 patients who presented by 2 months of age, SVT had disappeared in 93% by 8 months of age, but many had recurrences later in life [19]. Tortoriello found that patients without pre-excitation had a low (17%) risk of recurrence [4].