A 52-year-old male with a recent history of knee surgery is brought to the emergency department with acute onset of sharp chest pain, difficulty breathing, and coughing up blood. Vital signs include respiratory rate of 22 breaths per minute, heart rate of 110 beats per minute, and oxygen saturation of 89% on room air. His rhythm strip shows a regular tachycardia without specific ST or T wave changes. Which diagnostic test is most likely to confirm the suspected condition?
D-dimer test
Computed tomography pulmonary angiography (CTPA)
Chest radiograph
Rhythm strip review for specific changes