Final answer:
A patient exhibiting sharp chest pain, dyspnea, and right ventricular strain on an ECG is most likely experiencing a pulmonary embolism.
Step-by-step explanation:
A patient presenting with rapid onset of sharp, localized chest pain associated with dyspnea, clear breath sounds, and right ventricular strain on the 12 lead ECG is most likely suffering from a pulmonary embolism (PE). In contrast, a myocardial infarction (MI) typically presents with chest pain that is beneath the sternum and may radiate down the left arm, and is associated with symptoms such as irregular heartbeat, nausea, and sweating. Angina is chest pain or pressure due to inadequate blood flow and can be associated with shortness of breath and nausea, but does not necessarily indicate a heart attack. A spontaneous simple pneumothorax typically presents with sudden sharp chest pain and may or may not be associated with dyspnea, but is unlikely to show right ventricular strain on an ECG.