Review Question - QID 106824

Patient A and patient B present simultaneously to the emergency department with the same cardiac valvular pathology. Both patients are observed on physical exam to have a holosystolic murmur which radiates to the axilla and is worsened by the handgrip maneuver. Patient A is in severe distress, complains of acute onset of severe shortness of breath, and has the findings observed in Figure A. A chest radiograph and EKG obtained and demonstrated by Figures B and C, respectively. Meanwhile, patient B is relatively stable and complaining only of minor palpitations. A chest radiograph and EKG are obtained and demonstrated by Figures D and E, respectively. Differences in which of the following best explains the difference presentations despite the same underlying valvular pathology in these patients?