A 63-year-old man with an acute pulmonary embolism becomes hypotensive, confused, and severely hypoxemic. Echocardiography shows right ventricular dilation and strain. In the absence of contraindications, which treatment is most appropriate?

A 64-year-old man with metastatic lung cancer presents with hypotension, raised jugular venous pressure, muffled heart sounds, and pulsus paradoxus. What is the most likely diagnosis?

A 58-year-old man with diabetes and a 30-pack-year smoking history presents with central chest pain at rest lasting 40 minutes. ECG shows horizontal ST-segment depression in leads V4–V6, and cardiac troponin is elevated. What is the most likely diagnosis?

A 78-year-old man has exertional syncope, angina, and progressive dyspnea. Examination reveals a harsh crescendo-decrescendo systolic murmur at the right second intercostal space radiating to the carotids. Which valvular lesion is most likely?

A 65-year-old man with long-standing hypertension develops sudden tearing chest pain radiating to the back. Blood pressure differs between both arms, and a new early diastolic murmur is heard. Which diagnosis is most likely?

A woman with placental abruption develops diffuse bleeding from venipuncture sites. Laboratory studies show thrombocytopenia, prolonged PT and aPTT, reduced fibrinogen, and elevated D-dimer. Which mechanism best explains these findings?

A 41-year-old farmer presents after ingesting an unknown pesticide. He has salivation, lacrimation, diarrhea, bradycardia, and pinpoint pupils. Which treatment is most appropriate?

A 47-year-old woman develops sudden dyspnea and pleuritic chest pain seven days after hip surgery. Her pulse is 120/min, oxygen saturation is 87%, and the right calf is swollen. She is hemodynamically stable. Which investigation is most appropriate to confirm the diagnosis?

A 73-year-old man with a 50-pack-year smoking history is found to have a pulsatile abdominal mass. Ultrasound reveals a 6.3 cm infrarenal abdominal aortic aneurysm. What is the most appropriate management?

A 68-year-old man with heart failure and an ejection fraction of 30% is receiving an ACE inhibitor and a beta-blocker. He presents with worsening orthopnea, ankle edema, raised jugular venous pressure, and bilateral basal crackles. Which drug will most rapidly relieve his congestive symptoms?

A 69-year-old man develops acute pulmonary edema three days after an inferior myocardial infarction. A new systolic murmur is present, but imaging shows no left atrial enlargement. Why is pulmonary edema particularly severe?

A 53-year-old woman presents with severe headache, confusion, blurred vision, and a blood pressure of 230/135 mmHg. Fundoscopy shows papilledema, and serum creatinine is elevated. What is the most appropriate initial management?

A 74-year-old woman with atrial fibrillation is started on warfarin. Several days later, she develops painful skin necrosis over the breasts and thighs. Which mechanism most likely caused this complication?

A 62-year-old man presents with severe central chest pain, sweating, and nausea. ECG shows ST-segment elevation in leads II, III, and aVF. He is hypotensive, has raised jugular venous pressure, and his lungs are clear. Which artery is most likely occluded?

A 58-year-old man presents with fatigue, fever, weight loss, and a new murmur. Blood cultures are repeatedly negative because he received antibiotics before admission. Echocardiography shows valvular vegetations. Which diagnosis is most likely?

A 55-year-old woman presents 90 minutes after the onset of crushing chest pain. ECG shows ST elevation in leads V1–V4. Primary PCI is immediately available. In addition to aspirin, which drug inhibits platelet aggregation through blockade of the ADP P2Y12 receptor?

A 4-year-old child has poor weight gain and recurrent respiratory infections. Examination reveals a harsh holosystolic murmur at the lower left sternal border. Echocardiography shows a large ventricular septal defect. Which late complication may cause reversal of the shunt?

A 66-year-old man with long-standing hypertension presents with progressive exertional dyspnea, orthopnea, and bilateral ankle edema. Echocardiography shows a dilated left ventricle with an ejection fraction of 25%. Which myocardial change most likely explains the reduced systolic function?

A 61-year-old man presents three hours after the onset of severe chest pain. ECG shows ST elevation in leads I, aVL, and V1–V4. Which region of the myocardium is most likely infarcted?

A 62-year-old man with heart failure is started on spironolactone. One month later, he develops muscle weakness and cardiac conduction abnormalities. Which laboratory abnormality is most likely?

A 68-year-old man presents with hypotension, cool clammy extremities, oliguria, and elevated jugular venous pressure after a large anterior myocardial infarction. Which type of shock is most likely?

A 60-year-old man with chronic heart failure is started on digoxin. Several days later, he develops nausea, yellow-green visual disturbances, and an irregular cardiac rhythm. Which electrolyte abnormality increases the risk of this toxicity?

A 43-year-old woman with previous rheumatic fever has exertional dyspnea and intermittent hemoptysis. Auscultation reveals a loud S1, an opening snap, and a low-pitched mid-diastolic rumbling murmur at the apex. Which cardiac chamber is most likely enlarged?

A 67-year-old man with acute anterior STEMI is treated with primary PCI. Twelve hours later, he develops repeated runs of broad-complex tachycardia with hypotension and chest discomfort. What is the most appropriate immediate management?

A 58-year-old man with heart failure and reduced ejection fraction remains symptomatic despite appropriate diuretic therapy. Which drug class has been shown to reduce mortality by blocking maladaptive sympathetic activation?

A 55-year-old man with hypertension is started on hydrochlorothiazide. Two weeks later, he develops painful swelling of the first metatarsophalangeal joint. Which adverse effect of the drug most likely caused this problem?

A 29-year-old woman presents with dyspnea, palpitations, and fatigue. Auscultation reveals a midsystolic click followed by a late systolic murmur at the apex. Which diagnosis is most likely?

A 29-year-old man develops chest pain, palpitations, and dyspnea one week after a viral upper respiratory tract infection. Troponin is elevated, coronary angiography is normal, and echocardiography shows global left ventricular hypokinesia. What is the most likely diagnosis?

A 34-year-old man who injects drugs presents with fever, pleuritic chest pain, and hemoptysis. Blood cultures grow Staphylococcus aureus. A holosystolic murmur is loudest at the lower left sternal border and becomes louder during inspiration. Which valve is most likely affected?

A 57-year-old man with a history of tuberculosis has progressive peripheral edema, ascites, elevated jugular venous pressure, and a pericardial knock. Echocardiography shows preserved systolic function with impaired diastolic filling. What is the most likely diagnosis?

A 64-year-old man with resistant hypertension has an abdominal bruit. After starting lisinopril, his serum creatinine rises markedly within four days. What is the most likely underlying condition?

Five days after an inferior myocardial infarction, a 68-year-old man suddenly develops severe dyspnea, hypotension, and pulmonary edema. A new loud holosystolic murmur is heard at the apex and radiates to the axilla. What is the most likely complication?

A 25-year-old trauma patient has lost approximately 30% of his blood volume. He is tachycardic, hypotensive, and has cool extremities. Which compensatory response is most likely to occur first?

A 28-year-old woman presents with fatigue, weight loss, arthralgia, and painful erythematous nodules on her legs. She has absent pulses in one upper limb and a blood-pressure difference between both arms. Which diagnosis is most likely?

A 70-year-old woman with severe pneumonia becomes febrile, confused, and hypotensive. Her extremities are warm, her pulse is bounding, and serum lactate is elevated. Which hemodynamic pattern is most likely during the early phase of her condition?

A 20-year-old athlete collapses during intense exercise. His father died suddenly at 34 years of age. Examination performed previously revealed a harsh systolic murmur that became louder during the Valsalva maneuver. Which drug is most appropriate for long-term symptom control?

A 45-year-old man presents with fever and a new murmur. Blood cultures grow viridans streptococci. He recently underwent a dental extraction and has a history of a previously damaged mitral valve. Which pathological lesion is most likely present?

A 24-year-old man is referred after a routine lipid profile shows an LDL cholesterol level of 315 mg/dL. His father died from myocardial infarction at 39 years of age. Examination reveals firm nodules over the Achilles tendons. Which abnormality most likely underlies this condition?

A 36-year-old woman develops unilateral leg swelling and pain after a long-distance flight. Duplex ultrasound confirms deep venous thrombosis. Which component of Virchow triad was most directly promoted by prolonged immobility?

A 2-year-old child with tetralogy of Fallot becomes intensely cyanotic and dyspneic while crying. The child instinctively squats. How does squatting improve the episode?

A 71-year-old man presents with dizziness and recurrent syncope. ECG shows complete dissociation between P waves and QRS complexes, with a ventricular rate of 32/min. What is the most appropriate definitive treatment?

A 59-year-old man experiences substernal chest pressure while walking uphill. The discomfort resolves within five minutes of rest. His resting ECG and cardiac troponin are normal. What is the most likely mechanism of his symptoms?

A 60-year-old man presents with severe dyspnea, frothy pink sputum, diffuse crackles, and hypoxemia. His blood pressure is 190/110 mmHg. Which immediate intervention is most appropriate to reduce pulmonary congestion and cardiac preload?

A 44-year-old woman has progressive exertional dyspnea, loud P2, right ventricular heave, and elevated pulmonary artery pressure. Which structural change is most characteristic of chronic pulmonary hypertension?

A 49-year-old woman with hypertension and asthma requires additional blood-pressure control. Which antihypertensive drug should be avoided because it may precipitate bronchospasm?

A 62-year-old man receiving amiodarone for recurrent ventricular arrhythmias develops progressive dry cough and exertional dyspnea. Chest imaging shows diffuse interstitial infiltrates. Which adverse effect is most likely?

A 34-year-old man presents with sharp central chest pain that improves when he sits forward and worsens with deep inspiration. ECG shows widespread concave ST-segment elevation and PR-segment depression. Which diagnosis is most likely?

A 67-year-old man with severe aortic stenosis develops exertional chest pain despite having no significant coronary artery obstruction. What is the most likely explanation?

A 52-year-old woman with chronic heart failure is taking enalapril, carvedilol, spironolactone, and furosemide. She develops a persistent dry cough. Which drug is most likely responsible?

A 46-year-old woman has recurrent episodes of chest pain occurring at rest, usually in the early morning. During an episode, ECG shows transient ST-segment elevation that resolves after sublingual nitroglycerin. Which mechanism is most likely responsible?

A 28-year-old woman presents with sudden-onset palpitations. ECG shows a regular narrow-complex tachycardia at 190/min. Vagal maneuvers fail, and she is hemodynamically stable. Which drug is most appropriate?

A 10-year-old child has exertional leg fatigue, headaches, and recurrent epistaxis. Blood pressure is elevated in both arms but reduced in the legs. Femoral pulses are delayed. Which diagnosis is most likely?

A 59-year-old man with chronic atrial fibrillation suddenly develops severe pain, pallor, and absence of pulses in his left leg. The limb is cold and numb. What is the most likely cause?

A 36-year-old woman presents with progressive dyspnea and fatigue. Echocardiography shows normal ventricular size and systolic function but severe impairment of ventricular filling. Cardiac biopsy reveals extracellular amyloid deposits. Which type of cardiomyopathy is most likely?

A 76-year-old woman with hypertension and diabetes has persistent nonvalvular atrial fibrillation. She has no contraindication to anticoagulation. Which treatment provides the most effective long-term prevention of ischemic stroke?

A newborn has severe cyanosis immediately after birth. Echocardiography shows that the aorta arises from the right ventricle and the pulmonary artery arises from the left ventricle. Survival depends on mixing between the two circulations. Which lesion is present?

A 65-year-old man with chronic obstructive pulmonary disease develops atrial fibrillation with a rapid ventricular response. Which drug is most appropriate for ventricular rate control if severe bronchospasm makes beta blockers undesirable?

A 64-year-old man is recovering from an acute myocardial infarction. On the third hospital day, he suddenly loses consciousness. Cardiac monitoring shows a chaotic rhythm with no identifiable P waves or QRS complexes. Which rhythm is most likely?

A 3-year-old child has a continuous machinery-like murmur below the left clavicle and bounding peripheral pulses. Which congenital cardiac lesion is most likely?

A 72-year-old woman presents with a new unilateral headache, scalp tenderness, and jaw claudication. ESR is markedly elevated. Which immediate treatment is most appropriate to prevent a serious complication?