A 57-year-old woman presents with severe chest pain, which started abruptly earlier in the day, and general malaise of 2 weeks' duration. She has a history of hypertension.
The mildly obese patient is in obvious distress from her chest pain; her skin has a bluish cast. Temperature is 37.2°C (99°F); heart rate, 120 beats per minute with normal rhythm; respiration rate, 25 breaths per minute; and blood pressure, 86/50 mm Hg. Head and neck are normal. Lungs are clear. Heart tones are muffled. Pulses in the extremities are diminished, but sensation and motor skills remain intact.
A frontal upright radiograph of the chest is obtained. What does it reveal, and what further action would you take to arrive at a diagnosis?