Right-Sided Chest Pain, Elevated HR: Seen in the ED

A woman in her early 50s presents with 6 hours of right sided pleuritic chest pain. What do the history and ECG suggest? What's yoru Dx?

History of present illness: A woman in her early 50s with a history of chronic obstructive pulmonary disease (COPD) and hypertension treated with hydrochlorothiazide (HCTZ) presents to the emergency department complaining of 6 hours of right-sided pleuritic chest pain that is associated with dyspnea and palpitations. She denies any leg swelling or pain, fever, chills or other complaints

Vital signs and physical examination: Vital signs are normal except for a heart rate of 160 beats/min. Physical exam is otherwise normal. An ECG tracing is shown here.

What is the most likely cause of the ECG findings?