A 62-year-old man dies suddenly in his sleep.  The patient had a history of type 2 diabetes mellitus and hypertension, and he smoked a pack of cigarettes daily for 25 years.  His adherence to medical care was poor.  Autopsy is performed, and a histologic section of his left ventricular myocardium is shown below:

Which of the following directly promotes the formation of the tissue indicated by the arrow?

A 66-year-old woman comes to the office due to worsening chest discomfort and shortness of breath for the past 4 weeks.  There is no history of recent upper respiratory illness, fever, cough, palpitations, or syncope.  Medical history is significant for hypertension and breast adenocarcinoma treated with surgery and chemotherapy 6 years ago.  The patient does not use tobacco or alcohol and has not traveled recently.  Temperature is 37 C (98.6 F), blood pressure is 110/70 mm Hg, and pulse is 90/min.  Physical examination shows changes consistent with prior right mastectomy.  The right axillary lymph nodes are enlarged.  The lungs are clear to auscultation.  Heart sounds are distant with no murmur.  There is no extremity edema.  Bedside echocardiography shows a large pericardial effusion.  Pericardiocentesis in this patient is most likely to reveal which of the following findings?

A 19-year-old man comes to the office to establish medical care.  He is transitioning care from his pediatrician.  The patient states that he recently changed his glasses for myopia; he otherwise has no symptoms.  He takes no medications.  Vital signs are within normal limits.  On physical examination, the patient is tall with long upper extremities and fingers.  The face appears narrow with down-slanted palpebral fissures, flattened malar bones, and a small jaw.  The lungs are clear on auscultation.  A late-systolic murmur is present at the cardiac apex.  The abdomen is soft and nontender with no organomegaly.  Which of the following is the most likely cause of this patient’s murmur?

A 17-year-old girl is evaluated due to decreased exercise tolerance and fatigue.  She has no known medical conditions and takes no medications.  Blood pressure is 110/60 mm Hg and pulse is 88/min.  The lungs are clear on auscultation.  Cardiac examination reveals a parasternal heave, and a widely split second heart sound is heard throughout the respiratory cycle.  A systolic ejection murmur is present at the left upper sternal border.  Distal pulses are normal.  Echocardiography of this patient is most likely to demonstrate which of the following findings?

An 18-year-old woman is referred to a cardiologist after a heart murmur is discovered during a routine checkup.  The patient is healthy and has no symptoms.  Medical history is unremarkable.  She runs daily and wants to start actively training for a half marathon.  The patient is concerned that the murmur is a sign of heart disease.  She has no family history of sudden cardiac death.  Auscultation reveals a midsystolic click followed by a short late-systolic murmur at the cardiac apex.  The murmur disappears with squatting.  This patient’s condition is most likely related to an abnormality involving which of the following tissues?

A 75-year-old man is brought to the emergency department after his family found him to be lethargic and confused.  The patient has a history of hypertension, coronary artery disease, and heart failure.  Temperature is 35 C (95 F), blood pressure is 78/46 mm Hg, and pulse is 110/min.  The patient is admitted to the intensive care unit and a pulmonary artery catheter is placed, which demonstrates the following readings:

Which of the following is the most likely cause of this patient’s hypotension?

A previously healthy 15-year-old girl is brought to the emergency department due to respiratory distress and continuous cough after eating at a buffet in a local restaurant.  Blood pressure is 80/40 mm Hg, pulse is 130/min, and respirations are 32/min.  She is in marked respiratory distress but is able to speak.  Diffuse wheezing and erythematous skin rash are present.  Which of the following hemodynamic changes are most likely present in this patient?

A 64-year-old man comes to the emergency department due to chest discomfort and shortness of breath.  Medical history includes hypertension, type 2 diabetes mellitus, and severe osteoarthritis of the left knee.  The patient is an active smoker with a 20-pack-year smoking history.  He undergoes dobutamine infusion with simultaneous cardiac imaging.  The following is seen:

• Before infusion: normal left ventricular contractility, ejection fraction 60%

• During infusion: decreased apical contractility, ejection fraction 45%

• Five minutes after infusion: normal left ventricular contractility, ejection fraction 60%

Which of the following best explains the observed findings?

A 49-year-old woman comes to the emergency department with a 2-day history of fever, dysuria, and flank pain.  The patient has a history of poorly controlled type 2 diabetes mellitus.  Temperature is 38.3 C (101 F), blood pressure is 80/44 mm Hg, pulse is 134/min, and respirations are 34/min.  On physical examination, the patient appears lethargic, flushed, and diaphoretic.  Neck veins are flat.  The lungs are clear on auscultation and heart sounds are normal.  There is right-sided costovertebral tenderness.  Which of the following hemodynamic parameters are most likely to be present in this patient?

A 72-year-old man comes to the office due to palpitations, fatigue, and dyspnea for the past 2 weeks.  The patient experienced an episode of atrial fibrillation 4 years ago during hospitalization for pneumonia; the episode spontaneously resolved 2 days later.  Since then, he has had 3 episodes of symptomatic atrial fibrillation that self-terminated within a week.  Other medical history includes hypertension, type 2 diabetes mellitus, and chronic heart failure.  Blood pressure is 130/84 mm Hg and pulse is 110/min.  The lungs are clear to auscultation.  Cardiac examination demonstrates tachycardia with irregularly irregular heartbeats.  ECG confirms atrial fibrillation.  The patient’s ventricular rate is controlled with beta blocker therapy, but the arrhythmia fails to resolve as in previous episodes.  Which of the following factors is most likely involved in the progression of this patient’s arrhythmia?

A 56-year-old woman comes to the emergency department due to 3 days of fever, chills, and retrosternal chest pain.  She has end-stage kidney disease related to previous uncontrolled hypertension and receives intermittent hemodialysis through a tunneled catheter.  Temperature is 39 C (102.2 F), blood pressure is 108/64 mm Hg, and pulse is 120/min.  The patient is ill-appearing.  The lungs are clear to auscultation, but a pericardial friction rub is present.  Echocardiography reveals a moderate-sized pericardial effusion.  Pericardiocentesis yields turbid fluid with a large number of neutrophils.  Microbiologic analysis of this patient’s pericardial fluid is most likely to reveal which of the following pathogens?

A 41-year-old man comes to the emergency department due to 3 days of fever, chills, and nonproductive cough.  The patient has also felt tired and weak during this period.  He has a history of injection drug use and has been hospitalized several times for injection site cellulitis.  Temperature is 38.3 C (101 F), blood pressure is 125/72 mm Hg, and pulse is 112/min and regular.  Cardiopulmonary auscultation reveals scattered rhonchi and a cardiac murmur, which were not previously present.  Laboratory evaluation shows leukocytosis, and chest x-ray reveals nodular opacities.

Item 1 of 2

Echocardiography of this patient is most likely to reveal which of the following findings?

Item 2 of 2

The patient is started on an intravenous antibiotic for his condition but develops severe pruritus and a rash immediately upon infusion.  The antibiotic used in this patient demonstrates the following dynamics when tested in several healthy volunteers:

Which of the following antibiotics was most likely given to this patient?

A 29-year-old man is brought to the emergency department by his friend due to retrosternal chest pain for the past hour.  The patient is agitated and restless.  Temperature is 38.1 C (100.6 F), blood pressure is 180/106 mm Hg in the right arm and 182/104 mm Hg in the left arm, pulse is 110/min, and respirations are 20/min.  Physical examination shows bilaterally dilated pupils, normal heart and lung sounds, and a nontender abdomen.  ECG shows sinus tachycardia with ST-segment depression in the precordial leads.  Chest x-ray reveals no parenchymal opacities or pleural effusion and a normal mediastinum and cardiac silhouette.  Cardiac enzymes are normal.  Sublingual nitroglycerin and benzodiazepine therapy relieve the symptoms.  Which of the following is the most likely cause of this patient’s chest pain?

A 2-year-old boy is brought to the office due to fever.  For the past 6 days, he has had a fever of 39 C (102.2 F) to 40 C (104 F) that subsides minimally with acetaminophen.  Yesterday, his mother noted a rash on his diaper area.  Temperature is 39.2 C (102.6 F), pulse is 140/min, and respirations are 30/min.  Physical examination shows an irritable boy.  The patient’s neck is supple with full range of motion.  Both hands and feet are slightly erythematous and edematous, and a peeling rash is present over the perineal area.  His eyes and lips appear as shown.  The remainder of the examination is unremarkable.  Which of the following is the most likely diagnosis?

A 28-year-old man is found unresponsive by his roommate.  The roommate states the patient returned late last night after a party, and this morning he was unable to wake the patient up.  Paramedics find the patient without respirations and pulse and declare him dead.  Autopsy examination shows hemorrhage in the basal ganglia and midbrain that extends into the third ventricle.  There is no arteriosclerosis or fibrinoid necrosis of the arterioles.  Scattered areas of infarcted subendocardial myocardium are also seen.  A substance with which of the following synaptic effects most likely predisposed this patient to death?

A 1-hour-old neonate with prenatally diagnosed tetralogy of Fallot is admitted to the neonatal intensive care unit with cyanosis.  The mother is a 28-year-old gravida 3 para 2 who received routine prenatal care.  The patient was born via spontaneous vaginal delivery at 35 weeks gestation.  Initial Apgar scores are 5 and 7 at 1 and 5 minutes after birth, respectively.  The neonate’s lips, fingers, and toes appear cyanotic.  This patient should be immediately treated with a medication producing which of the following effects?

A 72-year-old man comes to the clinic due to episodic lightheadedness.  The episodes typically occur in the morning when the patient adjusts his shirt collar or tightens his tie and he briefly feels like he is going to pass out.  The patient had a thyroidectomy 5 years ago for a large benign tumor.  He also has hypertension and takes amlodipine.  Blood pressure is 135/78 mm Hg and pulse is 78/min.  Physical examination reveals no heart murmurs or carotid bruits.  ECG shows normal sinus rhythm.  The patient is given an ambulatory ECG monitoring device.  During symptomatic episodes, the device is most likely to show which of the following?

An 80-year-old woman is brought to the emergency department following a burn injury.  The patient lives alone in an apartment.  Earlier today, her clothes caught fire while she was cooking.  The patient’s neighbor heard her screaming and helped extinguish the fire, but the patient had already sustained burns on her face, arms, and body.  She has a history of Parkinson disease and osteoporosis.  Temperature is 37.4 C (99.3 F), blood pressure is 140/84 mm Hg, pulse is 110/min, and respirations are 18/min.  Oxygen saturation is 95% on room air.  On examination, the patient is in distress and anxious.  There are partial- to full-thickness burns involving the lower face, neck, both arms, and anterior chest and abdomen.  Which of the following age-related cardiopulmonary changes is most likely to increase this patient’s mortality risk?

An 81-year-old woman undergoes transcatheter aortic valve implantation through femoral access.  She was diagnosed with severe calcific aortic stenosis 2 months ago after she began having shortness of breath with mild exertion.  The vascular access is gained without complication, and the transcatheter valve is deployed under fluoroscopic guidance.  The following hemodynamic changes are observed:

Which of the following complications should be suspected in this patient?

A 6-month-old boy is brought to the emergency department due to lethargy for several hours.  His mother says he is usually a “very active baby,” and she is afraid that he is “coming down with something.”  The patient’s birth history is unremarkable, and he was born at 38 weeks gestation.  He is afebrile.  Blood pressure is 70/44 mm Hg, pulse is 240 beats/min, and respirations are 52/min.  The patient appears pale and is perspiring.  Capillary refill time is less than 2 seconds.  The lungs are clear to auscultation.  No murmurs are heard.  An ECG shows a regular heart rate of 240/min with narrow QRS complexes and no identifiable P waves.  Which of the following is the most likely cause of this patient’s hypotension?

A newborn is evaluated for cyanosis immediately after birth.  On examination, oxygen saturation is 70% in all 4 extremities and does not change despite 100% oxygen administration.  The patient’s lungs are clear to auscultation, and there are no heart murmurs or gallops.  Peripheral pulses are normal.  A chest radiograph reveals clear lungs and a normal cardiac silhouette but a narrowed mediastinal shadow.  Which of the following is the most likely cause of cyanosis in this patient?

A 25-year-old man comes to the emergency department due to chest heaviness and palpitations for the last 3 hours.  Over the past year, he has had similar episodes that resolved with deep breathing, but none lasted as long as this one.  The patient has no chronic medical conditions and takes no medications.  He does not use tobacco, alcohol, caffeine, or illicit drugs.  Blood pressure is 100/70 mm Hg, and pulse is 160/min and regular.  The neck is supple, the thyroid is normal, and there is no lymphadenopathy.  The lungs are clear to auscultation.  ECG is shown in the exhibit.  Which of the following is the most likely cause of this patient’s symptoms?

A 10-day-old boy born at home is brought to the emergency department due to difficulty breathing and sweating with feeds.  He was born at 38 weeks gestation via spontaneous vaginal delivery.  The patient has been breastfeeding every 2 hours for 5-10 minutes per side.  The mother notes that he sweats while he feeds, and his lips turn blue.  Weight is at the 5th percentile and length is at the 50th percentile.  On examination, the patient is currently not cyanotic.  There is a III/VI systolic crescendo-decrescendo murmur best heard along the left upper sternal border.  Chest x-ray is shown below:

Which of the following most likely represents the pressure changes that take place in this patient during feedings?

At autopsy, the heart of an 80-year-old man has a small left ventricular cavity and thickening of the left ventricle walls, which measure 1.7 cm (normal: 0.7-1.1) at the posterior and septal wall locations.  Microscopic examination shows diffusely enlarged cardiomyocytes, with prominent nuclei evident at low power.  Increased expression of which of the following substances most likely contributed to these pathologic findings?

A 4-year-old boy is brought to the office for routine evaluation of a heart murmur.  The patient has no fatigue, shortness of breath, or exercise intolerance.  He has no other medical conditions and has had no surgeries.  Vital signs are within normal limits.  On examination, the patient has no cyanosis or clubbing of the fingers.  There is a 2/6 holosystolic murmur best heard at the left lower sternal border.  There are no rubs or gallops.  Pulses are 2+ in the upper and lower extremities.  Compared to an unaffected child, which of the following changes in oxygen saturation would be expected in this patient?

A 62-year-old man comes to the office due to chest pain over the last 6 months.  He describes pressure-like pain in the substernal area when walking fast or climbing stairs that gradually subsides when he stops.  The patient does not smoke cigarettes or use illicit drugs.  He has no family history of heart disease or sudden death.  Physical examination shows a mid-systolic murmur at the upper sternum and slow-rising carotid pulses.  After initial evaluation, cardiac catheterization is performed and reveals 30% stenosis of the mid-left anterior descending artery.  A 50 mm Hg pressure gradient is seen when a catheter is passed across the aortic valve.  Which of the following is the most important contributor to this patient’s presenting symptoms?

A 54-year-old woman comes to the emergency department due to a 2-day history of fevers, chills, and severe fatigue.  She has no chronic medical problems and takes no medication.  Temperature is 38.9 C (102 F), blood pressure is 80/50 mm Hg, pulse is 130/min, and respirations are 20/min.  The patient’s left flank is tender to palpation.  Cardiovascular examination reveals tachycardia, decreased capillary refill, and an estimated jugular venous pressure of 3 cm H₂O above the sternal notch.  Laboratory results are as follows:

Which of the following is most likely decreased in this patient?

A 44-year-old man comes to the emergency department due to worsening abdominal pain and vomiting.  The patient has had 3 months of fatigue, mild abdominal pain, low-grade fever, and joint pains.  On examination, the abdomen is diffusely tender to palpation with rigidity and rebound.  Urgent laparotomy reveals bilateral renal infarcts and multiple segments of necrosis and perforation in the small bowel.  Microscopic examination of the vessel walls shows diffuse inflammation of the adventitia and marked thickening of the inner layers due to proliferation of loose connective tissue; the arterial lumen is significantly narrowed.  Which of the following is the most likely diagnosis?

A 64-year-old man dies suddenly while playing tennis.  In the preceding months, he experienced fatigue and some exertional dyspnea.  Autopsy is performed.  The heart examination shows left ventricular septal thickness of 1.6 cm (normal: <1.1), posterior wall thickness of 1.6 cm (normal: <1.1), and an internal left ventricular diameter of 3.2 cm (normal: 3.5-5.9).  No focal myocardial scarring is seen.  Which of the following is the most likely cause of the cardiac findings seen in this individual?

A 22-year-old woman comes to the office due to worsening dyspnea.  The patient has also experienced low-grade fevers, a 6.8-kg (15-lb) weight loss, and syncopal episodes over the last 3 months.  Her shortness of breath worsens when sitting and improves when lying down.  Medical history is insignificant.  The patient does not use tobacco, alcohol, or illicit drugs.  Temperature is 37.4 C (99.3 F), blood pressure is 115/72 mm Hg, pulse is 75/min and regular, and respirations are 12/min.  The lungs are clear.  Cardiac auscultation reveals a low-pitched, mid-diastolic rumble at the cardiac apex.  The remainder of the physical examination is normal.  ECG reveals left atrial enlargement, and echocardiography shows a large, pedunculated mass in the left atrium.  Histologic analysis of this mass will most likely reveal which of the following?

A 50-year-old man is brought to the emergency department due to chest pain.  He passed out briefly after the pain started.  Medical history includes hypertension, hyperlipidemia, and early-stage chronic kidney disease.  The patient reports that his father had a heart attack at a young age.  Despite treatment, the patient dies during hospitalization.  An autopsy is performed.  Light microscopy of the aortic wall is shown on the slide below.

A 55-year-old man is immediately brought to the hospital after experiencing a sudden collapse at home 20 minutes ago.  The patient reported chest pain and then collapsed to the floor while trying to sit down.  Medical history is significant for type 2 diabetes mellitus and hypertension.  Temperature is 36.7 C (98.1 F), blood pressure is 80/50 mm Hg, pulse is 120/min, and respirations are 22/min.  On examination, the patient is in marked respiratory distress.  Bilateral crackles are present.  An S3 is audible.  ECG reveals ST-segment elevation in leads V2 through V6.  Which of the following hemodynamic changes are most likely present in this patient?