Performance of a modified right atrial maze procedure versus CTI ablation was associated with lower recurrence rates.501 Alternatively, surgical repairs without arrhythmia intervention are associated with high recurrence rates of AT. Arrhythmia surgery can be combined with hemodynamic surgical revision with low mortality rate and improved medium-term freedom from arrhythmia recurrence and deathin this population. IIb B-NR Atrial pacing may be reasonable to decrease recurrences of AT or atrial flutter in ACHD patients and sinus node See Online Data Supplement 20. Small observational studies support the use of atrial pacing in patients with recurrent AT or atrial flutter to reduce the frequency of tachycardia episodes. The pacing rate is programmed to maintain atrial pacing for the majority of the time in patients with sinus node dysfunction, significantly reducing tachycardia recurrences to 11% in 1 study.509,510 In addition, the implanted pacemaker can be used for termination of recurrent episodes of AT or atrial flutter.472 Recommendations for Ongoing Management of SVT in ACHD Patients (Continued) COR LOE Recommendations Page et al 2015 ACC/AHA/HRS SVT Guideline e553 Pregnancy may confer an increased susceptibility to a variety of arrhythmias, even in the absence of underlying heart Pregnancy is also associated with an increased risk of arrhythmia exacerbation, such as more frequent and refractory tachycardia episodes, in patients with a pre-existing An important consideration is that adverse maternal and fetal outcomes have been reported as a result of SVT in pregnancy.515 Although there is potential tox- icity to the fetus with certain pharmacological and nonphar- macological therapies, safe options exist to allow for treating most cases of maternal SVT effectively. 