In an 85-year-old man with HTN and CAD who develops syncope after nitroglycerin for chest pain, what is the most appropriate next step in evaluation?

• A. Angiogram
• B. CT scan
• C. MRI
• D. Echocardiography

Answer: (D)

The test here is recognizing that syncope after nitroglycerin in an older patient with hypertension and coronary disease often points to a structural heart problem, such as severe aortic stenosis or dynamic LV outflow obstruction, rather than a simple ischemic event. Nitrates lower preload; in someone with a fixed stroke volume, like from a stenotic aortic valve, this preload reduction can precipitate a drop in blood pressure and loss of consciousness.

Transthoracic echocardiography directly assesses heart structure and function. It can reveal critical aortic stenosis by showing the valve anatomy and calculating gradients, quantify LV systolic function, and detect other causes such as LV outflow tract obstruction or cardiomyopathy. Because it is noninvasive, rapid, and widely available, it is the most informative next step to identify a potentially life‑threatening valve lesion or other structural abnormality that would change urgent management (for example, consideration of valve replacement).

Imaging that focuses on coronary anatomy or intracranial pathology, such as an angiogram, CT, or MRI, is not as immediately helpful for diagnosing the structural cause of syncope in this context and is more invasive or less rapidly informative.