A 56-year-old man experienced episodes of severe substernal chest pain every time he performs a task that requires moderate exercise. The episodes have become more frequent and severe over the past year, but they can be relieved by sublingual nitroglycerin. On physical examination, he is afebrile, his pulse is 78/min and regular, and there are no murmurs or gallops. Laboratory studies show creatinine, 1.1 mg/dL; glucose, 130 mg/dL; and total serum cholesterol, 223 mg/ dL. Which of the following cardiac lesions is most likely to be present in this man?

**Core Concept**
The patient's symptoms of exertional chest pain relieved by sublingual nitroglycerin suggest a diagnosis of variant (Prinzmetal's) angina or stable angina, but the episodic nature of the pain and its relation to physical activity point towards a specific type of coronary artery disease.

**Why the Correct Answer is Right**
The patient's symptoms are consistent with a diagnosis of variant angina, also known as Prinzmetal's angina. This condition is caused by transient vasospasm of a coronary artery, which leads to myocardial ischemia. The episodic nature of the pain and its relation to physical activity suggest that the vasospasm is triggered by increased oxygen demand during exercise. The relief of pain with sublingual nitroglycerin, a vasodilator, supports this diagnosis.

**Why Each Wrong Option is Incorrect**
**Option A:** Coronary artery thrombosis is not supported by the patient's symptoms, as there is no mention of acute myocardial infarction or sudden onset of chest pain.
**Option B:** Hypertrophic cardiomyopathy is not a likely diagnosis, as the patient's symptoms are related to exertion and relieved by vasodilators, rather than a fixed obstruction to outflow.
**Option C:** Coronary artery ectasia is a condition characterized by dilatation of the coronary arteries, but it does not typically present with symptoms of exertional chest pain relieved by vasodilators.

**Clinical Pearl / High-Yield Fact**
The patient's symptoms highlight the importance of considering variant angina in patients with exertional chest pain, particularly if the pain is relieved by vasodilators.

**Correct Answer:** D. Coronary artery spasm.

✓ Correct Answer: B. Coronary atherosclerosis