38 yo F evaluated for intermittent palpitations. A TTE demonstrates a 1.5 cm ostium secundum atrial septal defect. Right heart chambers are enlarged and the estimated pulmonary artery systolic pressures are normal. What is the most likely diagnosis?
a) Patent ductus arteriosus
b) Aortic stenosis
c) Atrial septal defect
d) Mitral valve prolapse
