A 52-year-old man comes to the office due to periodic substernal chest heaviness. The pain is precipitated by fast walking, especially uphill and against the wind, and remits after 5 minutes of rest. The patient has a history of hypertension and smokes a pack of cigarettes a day. Blood pressure is 140/80 mm Hg and pulse is 80/min. The lungs are clear to auscultation, and no heart murmurs are heard. There is no peripheral edema. Which of the following pathologic states is most likely to be present in this patient?

Question

A 52-year-old man comes to the office due to periodic substernal chest heaviness.  The pain is precipitated by fast walking, especially uphill and against the wind, and remits after 5 minutes of rest.  The patient has a history of hypertension and smokes a pack of cigarettes a day.  Blood pressure is 140/80 mm Hg and pulse is 80/min.  The lungs are clear to auscultation, and no heart murmurs are heard.  There is no peripheral edema.  Which of the following pathologic states is most likely to be present in this patient?

Quizplus · Accepted Answer

This patient with multiple risk factors for coronary artery disease (eg, age, hypertension, smoking) has intermittent substernal chest heaviness consistent with stable angina pectoris. Stable angina is characterized by substernal or left-sided chest pressure, tightness, or pain that is reliably produced by exertion and relieved by rest. It occurs due to temporary myocardial ischemia resulting from demand-supply mismatch of oxygen-rich blood to the myocardium. Myocardial oxygen demand is determined by heart rate, blood pressure (afterload), left-ventricular end-diastolic volume (preload), and cardiac contractility, whereas myocardial oxygen supply is determined by coronary blood flow. The demand-supply mismatch of stable angina results from restricted coronary blood flow due to a fixed atherosclerotic lesion that obstructs >70% of the coronary artery lumen. These lesions allow sufficient blood flow to the myocardium during rest but insufficient blood flow to meet myocardial oxygen demands during exertion. (Choice A) An atherosclerotic plaque obstructing 50% of the lumen is unlikely to produce symptomatic myocardial ischemia. Symptoms of stable angina do not become prominent until approximately 70% of the cross-sectional area of the coronary artery lumen is occluded. (Choice C) Ruptured atherosclerotic plaque with overlying fully obstructive thrombus describes the pathophysiology of ST elevation myocardial infarction. The abrupt cessation of myocardial blood flow leads to transmural infarction and presents with persistent chest pain that is not relieved by rest. (Choice D) Coronary artery vasospasm (vasospastic angina or Prinzmetal angina) results from hyperactivity of vascular smooth muscle, usually in the absence of significant atherosclerotic coronary artery disease. Transient anginal chest pain is typical; however, the pain is not precipitated by exertion or relieved by rest. (Choice E) Ulcerated atherosclerotic plaque with overlying partially obstructive thrombus is likely to produce acute coronary syndrome in the form of non-ST elevation (partial-thickness) myocardial infarction or unstable angina. Unstable angina describes anginal pain occurring at rest or with markedly increased frequency, intensity, or duration compared to the patient's baseline stable angina. Educational objective: Stable angina pectoris results from myocardial oxygen demand-supply mismatch and manifests as chest pressure, tightness, or pain that is reliably produced by exertion and relieved by rest. It most commonly occurs due to a fixed atherosclerotic plaque obstructing >70% of the coronary artery lumen that limits blood flow during exertion. __________ References: 2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease: a report of the American College of Cardiology Foundation/American Heart Association task force on practice guidelines, and the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. (http://www.ncbi.nlm.nih.gov/pubmed/23166211)

A 52-Year-Old Man Comes to the Office Due to Periodic