Abstract 17578: Pregnancy is Associated With Stable Right Ventricular Function but a High Burden of Arrhythmias in Women With Transposition of the Great Arteries After Atrial Switch

Introduction: Most adult patients with d-transposition of the great arteries (d-TGA) have undergone an atrial switch operation. Insufficient data exists regarding the effects of pregnancy on adverse outcomes, including RV failure, tricuspid regurgitation (TR), and atrial arrhythmias, in these patients. Hypothesis: We hypothesized that pregnancy in patients with TGA following atrial switch is associated with worsening RV systolic function and a high burden of arrhythmias. Methods: Longitudinal observational cohort study of adult women with TGA following atrial switch in a tertiary care adult congenital cardiology clinic. Serial echocardiogram, Holter, and EKG reports were reviewed. Ordinal variables were represented as percentages and medians. Results: A total of 20 patients were included. Of the 85% of patients with at least one pregnancy, 47% had 1 pregnancy, with a total of 29 pregnancies in the cohort. The most recent follow-up echo was done at a median of 54 months (30, 126 months) after last pregnancy. On most recent echo, patients had trace-mild TR (87.5%), mild pulmonary regurgitation (93.8%), moderate RV hypertrophy (60%), and mildly decreased RV systolic function (46%). Compared to echos prior to first pregnancy, there was no change in TR in 67% of patients, and 11% of patients had worsening TR from mild to moderate. Pulmonary valve regurgitation was unchanged in all patients. RV systolic function was stable except for one patient who had worsening from moderate to severe RV function. Arrhythmias were documented in 62.5% of patients, including atrial flutter (18.75%), atrial fibrillation (12.5%), accelerated junctional rhythm (6.25%), sick sinus syndrome (18.75%), SVT (6.25%), and Torsades (6.25%). 43.75% of arrhythmias were detected post-pregnancy. There were no deaths or hospitalizations for heart failure in the peripartum period. Conclusions: In conclusion, this study found that in women with TGA after atrial switch, pregnancy is not significantly associated with worsening RV systolic function, TR, and pulmonary valve regurgitation. Most patients developed arrhythmias at an incidence that was higher than seen in prior reports. Future work will assess if change of peak RV systolic strain predicts the development of arrhythmias.