A 71-year-old male comes to the physician for a 1-month history of shortness of breath when walking up the stairs in his house. There is no chest pain associated with these episodes. He has history of hypertension managed with hydrochlorothiazide. On physical examination, his lungs are clear to auscultation. Jugular venous pulsations are 3cm above the sternal angle. There is no peripheral edema. Pulse oximetry is 98% on room air. Which of the following is the most appropriate next step in diagnosis?
Coronary angiography
Exercise ECG stress test
Exercise echo stress test
Measurement of serum troponins
Ventilation-perfusion scan
