Mechanisms and Definitions For the purposes of this guideline, SVT is defined as per Table 3, which provides definitions and the mechanism(s) of each type of SVT. The term SVT does not generally include AF, and this document does not discuss the manage- ment of AF. 2.2. Epidemiology, Demographics, and Public Health Impact The epidemiology of SVT, including its frequency, pat- terns, causes, and effects, is imprecisely defined because of incomplete data and failure to discriminate among AF, atrial flutter, and other supraventricular arrhythmias. The best available evidence indicates that the prevalence of SVT in the general population is 2.29 per 1000 persons.32 When adjusted by age and sex in the US population, the incidence of paroxysmal supraventricular tachycardia (PSVT) is esti- mated to be 36 per 100 000 persons per year.32 There are approximately 89 000 new cases per year and 570 000 per- sons with PSVT.32 Compared with patients with cardiovas- cular disease, those with PSVT without any cardiovascular disease are younger (37 versus 69 years; P=0.0002) and have faster PSVT (186 bpm versus 155 bpm; P=0.0006). Women have twice the risk of men of developing PSVT.32 Individuals >65 years of age have >5 times the risk of younger persons of developing PSVT.32 Patients with PSVT who are referred to specialized cen- ters for management with ablation are younger, have an equal sex distribution, and have a low frequency of cardio- The frequency of atrioventricular nodal reentrant tachycardia (AVNRT) is greater in women than in men. This may be due to an actual higher incidence in women, or it may reflect referral bias. 