A patient 6 hours post - ST-elevation myocardial infarction (STEMI) develops sudden dyspnea, a new holosystolic murmur at the left lower sternal border, and a jugular venous distention (JVD) that was not present on admission. Hemodynamics show a step-up in oxygen saturation from the right atrium to the right ventricle. Which two findings are most consistent with the suspected mechanical complication? (Choose two.)