1. A 65-year-old man with a history of hypertension, diabetes, and coronary artery disease presents

to the emergency department with chest pain, dyspnea, and diaphoresis. He is diagnosed with an

acute myocardial infarction (AMI) and is given aspirin, nitroglycerin, morphine, and oxygen. He is

also scheduled for an urgent coronary angiography. Which of the following statements best

describes the pathophysiology of AMI?

a) AMI is caused by a sudden occlusion of a coronary artery by a thrombus that forms on a ruptured

atherosclerotic plaque.

b) AMI is caused by a gradual narrowing of a coronary artery by atherosclerosis that reduces blood

flow to the myocardium.

c) AMI is caused by a spasm of a coronary artery that temporarily interrupts blood flow to the

myocardium.

d) AMI is caused by an embolus that originates from the left atrium and lodges in a coronary artery.

*Answer: A. Rationale: AMI is most commonly caused by a sudden occlusion of a coronary artery by

a thrombus that forms on a ruptured atherosclerotic plaque. This leads to ischemia and necrosis of

the myocardial tissue supplied by the affected artery. The other options are less common causes of

AMI.*

2. A 50-year-old woman with a history of rheumatoid arthritis and chronic kidney disease is

admitted to the hospital with signs and symptoms of heart failure. She has bilateral crackles in her

lungs, jugular venous distension, peripheral edema, and an enlarged liver. Her blood pressure is

160/100 mmHg and her heart rate is 110 beats per minute. She is diagnosed with diastolic heart

failure and is started on diuretics, angiotensin-converting enzyme inhibitors, and beta-blockers.

Which of the following statements best explains the pathophysiology of diastolic heart failure?

a) Diastolic heart failure is caused by impaired ventricular relaxation that reduces diastolic filling

and stroke volume.

b) Diastolic heart failure is caused by increased ventricular contractility that increases systolic

ejection and afterload.

c) Diastolic heart failure is caused by reduced ventricular compliance that increases diastolic

pressure and pulmonary congestion.

d) Diastolic heart failure is caused by decreased ventricular preload that reduces cardiac output and

tissue perfusion.

*Answer: C. Rationale: Diastolic heart failure is caused by reduced ventricular compliance that

increases diastolic pressure and pulmonary congestion. This can result from conditions that cause

ventricular hypertrophy, fibrosis, or infiltration, such as hypertension, diabetes, ischemic heart

disease, rheumatic heart disease, or amyloidosis. The other options are not consistent with diastolic

heart failure.*

3. A 40-year-old man with a history of asthma and allergic rhinitis presents to his primary care

provider with wheezing, coughing, chest tightness, and shortness of breath. He reports that his

symptoms have worsened over the past week and that his albuterol inhaler does not provide much