A 39-year-old man comes to the emergency department with anterior chest pain.  He had felt well until the pain developed 4 days ago.  The patient says the pain is sharp and makes it difficult to take a deep breath.  Since yesterday, he has also felt out of breath.  Medical history is unremarkable.  The patient’s father died of a heart attack at age 52, and his mother suffers from rheumatoid arthritis.  He does not use alcohol or tobacco.  Temperature is 37.4 C (99.3 F), blood pressure is 112/65 mm Hg, and pulse is 103/min and regular.  Bedside ultrasound examination demonstrates a moderate pericardial effusion.  Which of the following is the most likely cause of this patient’s current condition?

A 55-year-old man is brought to the emergency department due to severe substernal chest pain that is accompanied by sweating and mild dyspnea.  The pain started as midline chest discomfort several hours ago but then progressively worsened such that the patient could not fall asleep.  He received sublingual nitroglycerin in the ambulance without significant pain relief.  His medical history includes hypertension, type 2 diabetes mellitus, and hyperlipidemia.  ECG demonstrates normal sinus rhythm and ST-segment elevation in leads I, aVL, and V1-V4, with deep Q wave development over the next several hours.  Cardiac catheterization in this patient would most likely show which of the following?

A 58-year-old man comes to the emergency department with abrupt-onset, severe chest pain that radiates to his back.  His blood pressure is 220/130 mm Hg in the left arm and 180/100 mm Hg in the right.  His heart rate is 100/min.  Initial laboratory studies show normal serum troponin levels.  Electrocardiogram is negative for ST-segment changes.  This patient’s acute condition was most likely triggered by which of the following events?

A 54-year-old man comes to the emergency department due to severe fatigue and dyspnea.  He has a long history of progressively worsening heart failure that has been resistant to treatment with medications, including diuretics.  He was treated with chest radiation 10 years ago for non-Hodgkin lymphoma and has been in remission since then.  The patient is admitted to the hospital, but his condition continues to deteriorate despite aggressive therapy.  He dies 3 days later, and an autopsy is performed.  Gross inspection of the heart shows dense, thick, fibrous tissue in the pericardial space between the visceral and parietal pericardium.  Which of the following signs would most likely have been detected during a physical examination of this patient just prior to his death?

A 32-year-old man comes to the emergency room due to severe headaches and vomiting.  Soon after, he becomes comatose and expires despite extensive resuscitation efforts.  Autopsy shows a ruptured cerebral aneurysm with extensive intracranial hemorrhage and a congenital heart defect.  This patient’s presentation is most likely associated with which of the following abnormalities?

A 30-year-old Asian man comes to the clinic due to painful, ulcerated fingers.  His symptoms began with pain and discoloration of the fingers several weeks ago, which progressed to ulceration at the fingertips.  He also reports pain in the hands that occurs with activity and is relieved by rest.  Medical history is unremarkable.  The patient has smoked 2 packs of cigarettes a day for the last 5 years.  He occasionally drinks alcohol but does not use illicit drugs.  Vital signs are within normal limits.  No heart murmurs are heard and the lungs are clear.  Examination of the hands is shown in the exhibit.  Radial pulses are diminished.  There is erythema and tenderness along a superficial vein of the left forearm.  Hemoglobin A1c and a fasting lipid panel are within normal limits.  Which of the following pathologic findings is most likely to be seen within the affected vessels?

A 20-year-old man comes to the office due to occasional palpitations that he describes as skipped beats.  He has no chest pain or shortness of breath.  Medical history is unremarkable.  On physical examination, the patient has wide, fixed splitting of S2.  No murmurs are heard.  Chest x-ray reveals enlargement of the right heart contour.  Echocardiographic findings are consistent with a congenital heart defect.  Repair of this patient’s congenital disease is aimed primarily at preventing irreversible changes to which of the following?

 65-year-old man comes to the emergency department with sudden onset of right-sided calf and foot pain.  His past medical history is significant for hypertension, type II diabetes mellitus, atrial fibrillation and stable angina.  Physical examination reveals paleness of the right leg and diminished right popliteal pulse.  Immediate angiography is ordered that reveals an obstructive thrombus in the right common femoral artery.  The thrombus extraction is followed by a rapid surge of serum creatine kinase level, which is best explained by:

A 32-year-old woman comes to the office due to exertional dyspnea that has progressed over the last year.  She can hardly walk a block without stopping to rest.  The patient’s mother died of “heart failure” at age 40.  During auscultation, the pulmonary component of S2 is louder than the aortic component in the right and left second intercostal space.  An accentuated impulse can also be palpated along the left upper sternal border.  Chest x-ray shows clear lungs.  Which of the following is the most likely cause of this patient’s findings?

A 22-year-old man comes to the office for an exercise evaluation.  He is an avid long-distance runner.  One of his team members was disqualified recently due to health issues, which made him worried about his own health.  He has no medical history and takes no medications or recreational drugs.  Blood pressure is 125/75 mm Hg and pulse is 55/min.  Examination shows no abnormalities.  Transthoracic echocardiogram results are as follows:

The right ventricle appears normal, and there are no valvular lesions.  Which of the following pathologic findings are most likely to be present within this patient’s heart?

A 34-year-old woman is brought to the emergency department due to chest pain.  The patient reports that she went to bed feeling well and woke up in the middle of the night with severe, crushing chest pain that radiated to her left arm.  She has had similar episodes over the past year that typically occur in early morning and spontaneously resolve after several minutes.  The patient has a history of occasional migraine that responds to acetaminophen.  She does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 150/100 mm Hg, pulse is 110/min, and respirations are 14/min.  On physical examination, the patient appears distressed and is diaphoretic.  ECG reveals ST-segment elevations in leads I, aVL, and V4-V6.  The patient is given nitroglycerin, which improves her symptoms.  Percutaneous coronary angiography is performed, and no obstructive lesions are observed.  Which of the following is most likely to be involved in the pathogenesis of this patient’s chest pain?

A 66-year-old man with diabetes mellitus is brought to the hospital due to sudden-onset chest pain and nausea.  Blood pressure is 70/60 mm Hg and pulse is 60/min.  Lungs are clear on auscultation.  ECG shows ST-segment elevation in leads II, III, and aVF.  Chest x-ray is unremarkable.  The patient is diagnosed with an inferior wall myocardial infarction.  Emergent cardiac catheterization reveals complete occlusion of the proximal right coronary artery.  He is persistently hypotensive in the cardiac catheterization laboratory.  Which of the following hemodynamic findings is most likely to be observed in this patient?

Atherosclerotic lesions of the coronary arteries can limit blood flow to the myocardial regions supplied by the affected vessels.  In some patients, certain medications can cause a redistribution of blood flow away from the ischemic areas, exacerbating existing myocardial ischemia.  Which of the following drug effects is most likely to produce this phenomenon?

The public health department of a developing country performs an epidemiologic study to assess the nationwide incidence of upper respiratory infections among children.  The data show a high rate of childhood bacterial pharyngitis.  Current practice guidelines indicate that a rapid test should be performed in children to identify the presence of bacterial antigens.  If this test is negative, a throat culture, the gold standard for definitive diagnosis, is then performed.  To offset cost and avoid losing patients to follow-up, the department is considering recommending the empiric use of penicillin for the treatment of suspected bacterial pharyngitis.  Which of the following would be expected to decrease after long-term implementation of this guideline?

An 82-year-old woman comes to the office due to fatigue, abdominal discomfort, and lower extremity swelling.  She also occasionally feels an uncomfortable pulsation in her neck.  Six weeks ago, the patient underwent pacemaker implantation due to sick sinus syndrome.  Episodes of lightheadedness that she had experienced before the procedure have now resolved.  The patient is afebrile, and other vital signs are normal.  Physical examination reveals bilateral, lower extremity edema and a tender, pulsatile liver.  The lungs are clear on auscultation.  The pacemaker implantation site has healed normally.  Complete blood count is normal.  What is the most likely diagnosis?

A 24-year-old man comes to the office for an exercise evaluation.  He is an avid long-distance runner.  One of his team members recently died suddenly in his sleep, which made the patient worried about his health.  He has no medical history, takes no medications, and does not use illicit drugs.  His maternal grandfather had a heart attack at age 40 and underwent coronary artery bypass surgery.  Blood pressure is 122/70 mm Hg and pulse is 49/min.  Transthoracic echocardiogram shows the following:

The right ventricular cavity is slightly enlarged and there are no valvular lesions.  Which of the following best explains this patient’s echocardiogram findings?

A 4-month-old boy is brought to the cardiology clinic by his parents for continued follow-up of tetralogy of Fallot.  The diagnosis was made during routine antenatal sonography, and the pregnancy and delivery were otherwise uncomplicated.  The infant has been seen frequently in the clinic and has not had any cyanosis, respiratory distress, or difficulty feeding.  The parents become concerned when their son’s surgical plan is discussed because he does not have the clinical signs that other children with tetralogy of Fallot demonstrate.  Which of the following is the major determinant of symptom severity in this condition?

A 55-year-old man comes to the office for follow-up.  The patient was diagnosed with hypertension 3 weeks ago, and an ECG performed at that time showed features of left ventricular hypertrophy.  He was subsequently referred for echocardiography.  The patient feels well and has had no shortness of breath, fatigue, or leg swelling.  He has no other medical conditions, takes no medications, and does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 155/90 mm Hg and pulse is 80/min.  BMI is 35 kg/m².  Physical examination shows normal jugular venous pressure.  There are no lung crackles, heart gallops, or lower extremity edema.  Echocardiography reveals a left ventricular ejection fraction of 30%.  Which of the following patterns of chemical mediators is most likely present in this patient?

A 32-year-old man comes to the emergency department with chest pain that started earlier in the day.  The pain is midline and sharp and increases with deep breaths but decreases when the patient leans forward.  He had a mild respiratory illness a week ago.  Other medical history is unremarkable.  The patient is a lifetime nonsmoker and has no family history of early-onset heart attack, sudden death, or cardiomyopathy.  Blood pressure is 120/70 mm Hg and pulse is 110/min and regular.  Which of the following physical examination findings is most expected in this patient?

A 67-year-old man is brought to the emergency department due to progressive shortness of breath.  He has had decreasing exercise tolerance for several months, and over the last week he could barely walk to the bathroom without becoming short of breath.  The patient has been sleeping in a semirecumbent position recently.  Medical history includes type 2 diabetes mellitus, hyperlipidemia, and a myocardial infarction 3 years ago.  He takes no medications.  The patient does not drink alcohol or use tobacco products.  BMI is 30 kg/m².  Oxygen saturation is 92% on room air.  The apical impulse is palpated in the 6th intercostal space along the anterior axillary line.  There is 3+ bilateral pitting edema in the legs.  Which of the following is most likely increased in this patient?

A 64-year-old woman who was discharged from the hospital 4 days ago comes to the emergency department due to chest tightness and severe shortness of breath.  During evaluation, the patient becomes unresponsive and goes into cardiac arrest.  Despite appropriate lifesaving measures, there is no return of spontaneous circulation and she is pronounced dead.  Autopsy examination is performed, and the myocardial findings are shown in the image below.

Which of the following most likely predisposed this patient to the observed cardiac findings?

A 72-year-old man comes to the office due to progressive shortness of breath.  Over the past year, the patient has been unable to perform many of his usual outdoor activities, including afternoon walks and working in the yard.  During the last several weeks, he has frequently become easily fatigued and short of breath, and at night he needs several pillows to sleep comfortably.  He has also had ankle swelling.  The patient has had no chest pain, syncope, abdominal pain, or cough.  He is a lifetime nonsmoker.  Bibasilar crackles are heard on physical examination.  Echocardiography reveals no valvular disease and a nondilated left ventricle with an ejection fraction of 55%.  Which of the following is most strongly associated with this patient’s current condition?

A 53-year-old man comes to the office with progressive exertional dyspnea.  He has smoked 2 packs of cigarettes per day for the last 35 years.  Physical examination shows increased anteroposterior diameter of his chest.  Auscultation reveals decreased breath sounds and scattered wheezes throughout his lungs.  Examination of his extremities is unremarkable.  Echocardiography reveals moderate dilation of the right ventricle and increased central venous pressure.  The absence of peripheral edema in this patient is best explained by which of the following compensatory mechanisms?

A group of researchers is studying population-based screening interventions to reduce mortality from abdominal aortic aneurysm.  This disorder develops primarily in elderly patients and is often asymptomatic until an acute rupture event, which is frequently fatal.  Screening of high-risk patients for abdominal aortic aneurysm is found to reduce mortality.  Which of the following risk factor combinations would likely define the highest-risk group for screening purposes?

A 32-year-old woman comes to the emergency department with lightheadedness and shortness of breath, which started while shopping at a supermarket.  During the last 6 months, she had increasing shortness of breath and had to adjust her daily activities.  The patient has no other medical problems and does not use tobacco, alcohol, or illicit drugs.  There is no family history of heart disease, stroke, or blood clots.  Her BMI is 25 kg/m².  After initial assessment, the patient reports that she feels “fine,” refuses further evaluation, and insists on being discharged.  She dies a month later.  At autopsy, her heart has the following appearance (RV, right ventricle; LV, left ventricle):

Which of the following is the most likely diagnosis?

A 56-year-old man comes to the emergency department due to progressively worsening dyspnea.  The patient can walk only a few blocks before becoming short of breath.  He also finds it difficult to sleep lying flat and requires 3 pillows to prop himself upright when sleeping.  Other medical problems include long-standing hypertension, for which he occasionally takes his prescribed antihypertensive medication.  The patient does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 170/100 mm Hg, and pulse is 80/min and regular.  Physical examination reveals bilateral basilar lung crackles, jugular venous distension, and bilateral lower extremity edema.  Chest x-ray reveals cardiomegaly and hilar prominence.  ECG shows left ventricular hypertrophy.  Echocardiogram shows elevated pressures in the pulmonary artery.  Which of the following is the most likely underlying cause of the observed echocardiographic finding in this patient?

A 63-year-old man comes to the emergency department due to progressive dyspnea and fatigue.  Over the last week, he has not been able to lie flat due to difficulty breathing and has had to sleep in a sitting position.  He had an anterior myocardial infarction 6 months ago and has not been compliant with his medication regimen since that time.  Medical history is also significant for hypertension.  The patient is an ex-smoker with a 30-pack-year history.  He does not drink alcohol.  His father died of a heart attack at age 60.  Blood pressure is 170/100 mm Hg, and pulse is 100/min and regular.  Oxygen saturation is 90% on room air.  He is afebrile.  Auscultation reveals crackles at the lung bases, an S3 gallop, and a II/VI holosystolic murmur over the apex.  The patient is admitted to the hospital, and after treatment with diuretics and vasodilators his condition improves significantly.  Three days later there are no appreciable gallops or murmurs on cardiac examination.  Which of the following best explains the murmur heard at the time of the initial examination?

A 52-year-old man comes to the emergency department due to several days of vague chest pain and cough.  He immigrated to the United States from Taiwan 20 years ago.  Temperature is 37.1 C (98.8 F).  Physical examination reveals a decrescendo-type diastolic murmur over the right sternal border.  Pulmonary auscultation reveals normal breath sounds with no wheezes or rales.  Abdominal examination shows no organomegaly.  Serum fluorescent treponemal antibody absorption testing is positive.  Chest x-ray reveals mediastinal widening.  The pathologic process most likely responsible for this patient’s symptoms starts as which of the following?

An 18-year-old woman comes to the emergency department for evaluation of a rash.  The patient developed mild aches involving her knees and ankles 2 days ago.  Before going to sleep last night, she noticed purplish spots around her right knee.  Today, the rash involves both of the lower extremities.  She has had no fever, weight loss, sore throat, abdominal pain, vomiting, or diarrhea.  The patient has no chronic medical conditions and takes no medications.  Temperature is 37 C (98.6 F), blood pressure is 146/90 mm Hg, pulse is 90/min, and respirations are 20/min.  Cardiopulmonary examination is unremarkable.  The patient has pain with passive range of motion of the knees and ankles.  Skin examination is seen in the exhibit.

Laboratory results are as follows:

Histologic examination of the rash is most likely to show which of the following?

A 25-year-old man with an insignificant medical history was playing soccer when he suddenly collapsed.  Despite all attempts to save his life, he died.  Autopsy is performed.  Gross examination of the heart reveals a weight of 580 g (normal: <350).  The cut surface of the heart is shown in the image.

If this patient had a preparticipation sports screening, cardiac auscultation would have likely revealed a murmur that increases in intensity after which of the following?

A 56-year-old man is brought to the emergency department due to burning substernal pain that began 6 hours ago.  The patient has a history of type 2 diabetes mellitus and hypertension.  He smokes 2 packs of cigarettes daily and consumes alcohol occasionally.  An ECG performed in the emergency department shows ST segment elevation in leads I, aVL, and V3-V6.  During the next several hours, the patient develops progressive shortness of breath that worsens when lying flat.  Which of the following histologic features is most likely to be present in this patient’s lung tissue?

A 43-year-old man is hospitalized with recent-onset oliguria and a high serum creatinine level.  He has been seen in clinic several times for an intranasal ulcer that has failed to heal.  This patient’s condition is most likely associated with antibodies against which of the following?