Review Question - QID 213403

A 36-year-old woman presents to her primary care physician for her yearly physical exam. She says that she has been experiencing some mild shortness of breath, but otherwise has no medical complaints. Her past medical history is significant for allergies and asthma as a child, but she is not currently taking any medications or supplements. She does not smoke and drinks about 2 glasses of wine per week as a social activity. On physical exam she is asked to take deep breaths during cardiac auscultation. The physician notices that the splitting of S2 decreases during inspiration. Which of the following is most consistent with this physical exam finding?