A 27-year-old man was assaulted and stabbed on the left side of the chest between the areola and the sternum. He is hemodynamically unstable with jugular venous distention, distant hea sounds, and hypotension. Which of the following findings would be consistent with a diagnosis of hemodynamically significant cardiac tamponade?

On physical examination, cardiac tamponade may manifest with Beck triad (systemic hypotension, jugular venous distention, and distant hea sounds). Also, the patient may have pulsus paradoxus, which is manifested by a decrease in systolic blood pressure by more than 10 mm Hg at the end of the inspiratory phase of respiration. On echocardiogram, there will be pericardial fluid and right atrial collapse. On Swan-Ganz monitoring, there will be equalization of pressures across the four chambers. The right atrial pressures and central venous pressure are increased and cardiac output is decreased.