A 26-year-old woman comes to the physician for a follow-up appointment. Cardiopulmonary examination shows a 2/6 early-systolic murmur and a wide, fixed splitting of S2. Which of the following is most likely to be seen in this patient?
Left ventricular dilatation
Increased endothelin-1 activity
Increased pulmonary capillary wedge pressure
Interventricular left-to-right shunt
Interventricular right-to-left shunt