A 68-year-old man with substernal chest tightness on exertion that lasts about five minutes and is relieved by rest. Resting ECG and labs are normal. What is the most likely next step in diagnostic evaluation?

• A. Radionuclide angiography
• B. Exercise ECG
• C. Myocardial perfusion scintigraphy
• D. Stress echocardiography

Answer: (B)

In suspected stable angina, if the patient can exercise and the resting ECG is normal, the first noninvasive test is an exercise treadmill ECG. It directly tests for inducible ischemia by watching for chest pain and ST-segment changes during controlled exertion, and it provides both diagnostic and prognostic information at low cost and with wide availability. A positive or nondiagnostic exercise ECG would prompt further evaluation with imaging-based stress testing, such as stress echocardiography or myocardial perfusion imaging, to improve diagnostic accuracy or assess risk.

Radionuclide angiography primarily assesses ventricular function rather than ischemia and is not the preferred initial test in this scenario. Myocardial perfusion scintigraphy and stress echocardiography are more sensitive, but are typically reserved for instances where the resting ECG is abnormal, the patient cannot exercise adequately, or there is a nondiagnostic or equivocal treadmill test.