Question 1

A 45-year-old man with known HIV infection comes to the emergency department due to a rash that began on his hands 4-5 weeks ago but then spread to involve his upper arms, shoulders, and ears. He has no fever, trauma, recent travel, or insect bites. He lives in a shelter and has poor medical follow-up. The patient was treated in the past for Candida esophagitis and Pneumocystis jirovecii pneumonia. His CD4⁺ cell count 6 months ago was 50/µL. His temperature is 36.7 C (98 F), blood pressure is 126/80 mm Hg, and pulse is 80/min. Photographs of the patient's skin examination are shown below. Which of the following is the most likely diagnosis?

Accepted Answer

Simple scabies is due to the Sarcoptes scabiei mite, which burrows into the skin and spreads through person-to-person contact. It usually presents with an intensely pruritic rash in the flexor surfaces of the wrist, lateral surfaces of the fingers, and the finger webs. It can also involve other parts of the body but less commonly affects the back and head (except in children). Examination usually shows excoriations with small, crusted, red papules. scabies In contrast, crusted scabies is an overwhelming infestation with thousands (compared to <50 in simple scabies) of scabies mites that is more common in elderly or immunocompromised (eg, HIV) patients. Crusted scabies causes little or no itching, and presents insidiously with poorly defined erythematous patches that progress to prominent scales, crusting, and malodorous fissures. Affected areas can include the palms, extensor surfaces of the hands and elbows, scalp, ears, feet, and toes. Patients may develop secondary infections of the skin. Diagnosis is confirmed by skin scraping or dermatoscopy showing the mites and eggs. Simple scabies can be treated with topical permethrin, but topical agents alone are not as effective for crusted scabies due to the significant mite burden and the extensive crusting that diminishes penetration of the drug. Treatment requires oral ivermectin along with topical application of a keratolytic agent (eg, 20% urea ointment) and permethrin. (Choice B) Eczema in adults usually presents as erythematous plaques with thickened skin, lichenification (increased skin markings), and excoriation. The rash is usually pruritic and commonly involves the neck, antecubital fossa, popliteal fossa, face, wrists, and forearms. Eczema (Choice C) Psoriasis presents with well-defined erythematous, scaly plaques involving the scalp, extensor surfaces of the elbows, knees, external ear, and back. Psoriasis can be more severe in HIV patients with involvement of the palms, feet, nails, and sometimes widespread erythroderma. However, this patient's involvement of the hands, shoulders, and face makes psoriasis less likely. Psoriasis (Choice D) Seborrheic dermatitis usually presents as erythematous patches with a fine greasy scale on the scalp, eyebrows, central face, and trunk. Patients with HIV can have more severe, widespread seborrheic dermatitis, but this patient's crusting and fissuring is more consistent with crusted scabies. widespread seborrheic dermatitis (Choice E) Tinea corporis is a dermatophyte infection that causes a ring of erythema and scaling as opposed to the diffuse crusted lesions seen in this patient. Tinea corporis Educational objective: Crusted scabies is an overwhelming infestation with thousands (compared to <50 in simple scabies) of scabies mites. It is more common in the elderly and immunocompromised (eg, HIV) and presents with erythematous patches that progress to prominent scales, crusting, and malodorous fissures. Itching is mild or absent. Treatment requires oral ivermectin with a topical keratolytic agent (eg, 20% urea ointment) and permethrin. __________ References: Crusted scabies. (http://www.ncbi.nlm.nih.gov/pubmed/19584457)

Question 2

A 78-year-old woman is brought to the emergency department with left hip pain after a mechanical fall at home.  Her medical history includes knee osteoarthritis, hypertension, hyperlipidemia, and a myocardial infarction requiring bare-metal stent placement 14 months earlier.  Her medications include acetaminophen, low-dose aspirin, and simvastatin.  She had previously been prescribed a beta blocker but stopped taking it a couple months ago due to fatigue.  At baseline, she is able to eat, dress, and use the bathroom without assistance.  The patient is able to walk up only half a flight of stairs before stopping due to knee pain.  She has no chest pain, shortness of breath, or palpitations.  She is a lifetime nonsmoker.
The patient appears comfortable after intravenous morphine injection.  Blood pressure is 154/80 mm Hg and pulse is 64/min.  Oxygen saturation is 96% on room air.  Physical examination shows an externally rotated and shortened left leg.  No murmurs are heard on cardiac auscultation.  Lungs are clear to auscultation.
Laboratory results are as follows:
 ECG demonstrates normal sinus rhythm with Q waves in the inferior leads.  X-ray of the left hip and pelvis demonstrates a displaced intertrochanteric fracture.  Transthoracic echocardiogram obtained 6 months earlier reveals inferior wall hypokinesis, a left ventricular ejection fraction of 50%, evidence of mild diastolic dysfunction, and no major valvular abnormalities.
Which of the following is the most appropriate next step in management of this patient?

Accepted Answer

11ec193a_95df_7602_853d_6f72235f849f_MD0002_00 Managing perioperative cardiac risk prior to noncardiac surgery requires consideration of the type of surgery planned as well as patient clinical risk factors and functional status. In the absence of an active high-risk cardiac condition, patients undergoing low-risk surgery can proceed with surgery without further evaluation. Those undergoing intermediate- or high-risk surgery should undergo cardiac risk stratification using a validated prediction model such as the Revised Cardiac Risk Index (RCRI). Patients at low perioperative cardiac risk (≤1%) can undergo surgery without further evaluation, whereas those at moderate or high risk (>1%) should undergo assessment of functional status to determine the need for further evaluation prior to surgery. Although risk estimates vary, the American Board of Internal Medicine calculator uses these estimates for RCRI. high-risk cardiac condition low-risk surgery validated prediction model functional status This patient's hip fracture repair is an intermediate-risk surgery. Based on the RCRI, she has one clinical risk factor for a major cardiac complication (history of ischemic heart disease), indicating a low perioperative cardiac risk (~1%). Such patients can proceed with surgery without further cardiac evaluation. Asymptomatic patients with a moderate or high perioperative cardiac risk (>1%) who can perform >4 METS of activity also do not need further cardiac evaluation. Preoperative stress testing is recommended in patients who are at moderate or high cardiac risk (>1%) based on the RCRI and have poor (or unknown) functional status (inability to perform ≥4 METS of activity) if the results of such testing will change management (Choice A). (Choice C) Transthoracic echocardiogram is recommended prior to surgery in patients with evidence of decompensated heart failure or suspicion for significant valvular disease (eg, severe aortic stenosis). This patient's recent echocardiogram shows mild diastolic dysfunction, and she has never had symptoms to suggest decompensated heart failure (eg, exertional dyspnea, lower extremity edema). (Choice D) There is no significant evidence that patients with mild to moderate hypertension (eg, <180/110 mm Hg) are at increased perioperative risk, so preoperative initiation of antihypertensive medication (eg, lisinopril) is not indicated. ACE inhibitors are indicated for systolic, but not diastolic, left ventricular dysfunction. (Choice E) Even in patients with a cardiovascular indication for a beta blocker, initiating or restarting therapy is not recommended in the immediate preoperative period due to increased rates of hypotension, stroke, and all-cause mortality. Patients already on a beta blocker should continue it perioperatively. Educational objective: Noninvasive cardiac evaluation (eg, stress testing, echocardiography) is not indicated in most asymptomatic patients undergoing noncardiac surgery. It is reserved mainly for patients undergoing intermediate- or high-risk noncardiac surgery who have >1% estimated perioperative cardiac risk and poor functional capacity (<4 METS). __________ References: Preoperative cardiac risk assessment in geriatric patients with hip fractures: an orthopedic surgeons' perspective. (http://www.ncbi.nlm.nih.gov/pubmed/21057998) Effects of extended-release metoprolol succinate in patients undergoing non-cardiac surgery (POISE trial): a randomized controlled trial. (http://www.ncbi.nlm.nih.gov/pubmed/18479744)

Question 3

A 65-year-old woman is brought to the hospital for severe chest pain that started 7 hours ago.  She was hospitalized 6 weeks ago with ischemic stroke and treated with aspirin and rosuvastatin.  During that hospitalization, the patient had paroxysmal atrial fibrillation and was started on warfarin therapy.  Her last INR 2 days ago was 2.1.  The patient has mild, residual left-sided weakness.  Her past medical history is also significant for hypertension.
Blood pressure is 165/90 mm Hg and heart rate is 98/min and regular.  Chest examination shows crackles at the lung bases.
Electrocardiogram (ECG) shows normal sinus rhythm with 2 mm ST-segment elevation in leads V1-V4.
Which of the following is an absolute contraindication to fibrinolytic therapy in this patient?

Accepted Answer

Acute ST-elevation myocardial infarction can be treated with fibrinolytic therapy (FT) or percutaneous coronary intervention. This patient has multiple contraindications to fibrinolysis. However, the only absolute contraindication is the occurrence of an ischemic stroke within the last 3 months. If the stroke had occurred more than 3 months prior to her presentation, it would be a relative contraindication to FT. Patients with a relative contraindication may still receive FT if the benefits outweigh the risks. Prior history of intracranial hemorrhage (time unlimited) is another absolute contraindication. (Choice A) Although aspirin or other antiplatelet inhibitors should not be administered in the first 24 hours after FT, it is not an absolute contraindication to fibrinolysis. (Choice B) Poorly controlled hypertension (systolic blood pressure >180 mm Hg and diastolic blood pressure >110 mm Hg) is a relative contraindication to thrombolysis. Therefore, this patient's blood pressure does not qualify as a contraindication. (Choice D) The mortality benefit from FT is greatest when it is given within the first 60-70 minutes of symptom onset. FT can be administered for up to 12 hours from onset of symptoms, but the benefit declines rapidly after this time. (Choice E) Warfarin therapy with an elevated INR is a relative contraindication to FT. The higher the INR, the greater is the risk for bleeding after fibrinolysis. This patient's INR is 2.1. However, it is not an absolute contraindication if the benefits outweigh the risks. Educational objective: Ischemic stroke is an absolute contraindication to fibrinolytic therapy if the stroke occurred within the last 3 months and a relative contraindication if it occurred more than 3 months ago. Prior history of intracranial hemorrhage (time unlimited) is also an absolute contraindication. __________ References: ACC/AHA guidelines for the management of patients with ST-elevation myocardial infarction-executive summary. (http://www.ncbi.nlm.nih.gov/pubmed/15358045)

Question 4

A 43-year-old man comes to the emergency department with a 3-day history of fever, malaise, and chills.  He was hospitalized a year ago for alcohol withdrawal symptoms but otherwise no medical history is available.  He admits to using intravenous drugs.
The patient's temperature is 38.4 C (101.1 F), blood pressure is 144/90 mm Hg, and pulse is 102/min.  He has poor oral dentition.  A small white plaque is seen on the buccal mucosa.  Cervical lymph nodes are palpable bilaterally but are small and nontender.  Lungs are clear on auscultation.  There is a short 2/6 early diastolic murmur heard at the right upper sternal border.  The abdomen is soft and nontender.  Extremity pulses are full and symmetric, and there is no edema.
Laboratory results are as follows:

Blood cultures are sent.
Which of the following tests is most important for making treatment decisions at this point?

Accepted Answer

11ec193a_95e7_3e39_853d_69de666557ee_MD0002_00 This patient's clinical presentation (fever, malaise, and heart murmur [aortic regurgitation]) and history of intravenous drug use are highly suggestive of infective endocarditis (IE). The diagnosis of IE is based on a combination of clinical, laboratory and imaging characteristics (modified Duke criteria). A transthoracic or transesophageal echocardiogram is essential for the diagnosis and appropriate management of patients with suspected IE. Early echocardiography helps to characterize the size and location of valvular vegetations, severity of valvular regurgitation, and associated complications (perivalvular abscess, leaflet perforation, and/or fistula formation). It can also identify the subset of patients who may benefit from early surgical intervention to reduce the frequency of embolic events, recurrent IE, and risk of cardiovascular morbidity and mortality. surgical intervention (Choices A and B) This patient's leukocytosis and thrombocytopenia are appropriate inflammatory responses to the infection, and are unlikely to represent hematologic malignancy. A peripheral blood smear or bone marrow biopsy is not indicated at this time. (Choice C) A CT scan has no role in the initial diagnostic evaluation of endocarditis, though it may be helpful for further assessment if echocardiography is inconclusive. (Choice E) Fever, cervical lymphadenopathy, and oral mucosal lesions in an intravenous drug user are suggestive of HIV infection. However, an echocardiogram should be obtained first to screen for IE and identify associated complications that might require early surgical intervention. Educational objective: An echocardiogram should be obtained early in patients with suspected infective endocarditis to identify the size and location of valvular vegetations, the degree of valvular regurgitation, and associated complications (perivalvular abscess, leaflet perforation, and/or fistula formation). __________ References: Infectious endocarditis: diagnosis and treatment. (http://www.ncbi.nlm.nih.gov/pubmed/22612050)

Question 5

A 76-year-old man is brought to the emergency department after having 6 hours of shortness of breath and chest pain.  His initial blood pressure is 102/72 mm Hg and pulse is 102/min.  His oxygen saturation is 82% on 15 liters of oxygen via face mask.  Bilateral rales are heard over the lower to middle lung fields.  His initial ECG shows sinus tachycardia and a left bundle branch block.  He is intubated and rushed to the cardiac catheterization lab.
He is found to have an occluded proximal left anterior descending artery and mild atherosclerosis involving the other coronary arteries.  He has successful percutaneous revascularization with restoration of coronary flow.  A pulmonary artery catheter is placed at the end of the procedure for hemodynamic monitoring and he is transferred to the coronary care unit.  His current medications include aspirin, clopidogrel, intravenous unfractionated heparin, eptifibatide, furosemide, and propofol.  Six hours after the procedure, his blood pressure is 78/48 mm Hg, and his pulse is 120/min and regular.  His ECG shows sinus tachycardia and left bundle branch block pattern.
Hemodynamic readings from the pulmonary artery catheter show the following:

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

Accepted Answer

11ec193a_95d7_adcb_853d_0f43cb441e22_MD0002_00 This patient's pulmonary artery catheterization readings show a low cardiac index and an elevated pulmonary capillary wedge pressure in the setting of a recent myocardial infarction. These findings are suggestive of significant left ventricular dysfunction, and cardiogenic shock is the most likely cause of his hypotension. (Choice B) There is a compensatory increase in cardiac output/index in the early stages of septic shock. Pulmonary capillary wedge pressure and systemic vascular resistance are typically reduced, which is useful for differentiation from other causes of shock. (Choice C) Patients with hypovolemia usually have low right atrial and pulmonary capillary wedge pressures, decreased cardiac index, and increased systemic vascular resistance. (Choice D) Pericardial tamponade causes increased right atrial and ventricular pressures and characteristic equalization of right atrial, right ventricular end diastolic, and pulmonary capillary wedge pressures. (Choice E) Patients with pulmonary embolus have elevated right atrial, right ventricular, and pulmonary artery pressures. Pulmonary capillary wedge pressure and systemic vascular resistance are generally not affected. Educational objective: Patients with cardiogenic shock will have a low cardiac index, increased systemic vascular resistance, and elevated pulmonary capillary wedge pressure. __________

Question 6

A 72-year-old man comes to the emergency department because of palpitations and shortness of breath for the past 24 hours.  His medical problems include hypertension, hyperlipidemia, type 2 diabetes mellitus, obstructive sleep apnea, and emphysema.  He uses 2 liters of oxygen only during the night.  He cannot recall his medications, but uses an unknown daily inhaler for his "lung disease."  He quit smoking 12 years ago.
His blood pressure is 132/54 mm Hg and pulse is 155/min.  There is faint end expiratory wheezing noted over both lungs.  No murmurs are appreciated.  There is bilateral 1+ edema in his lower extremities.
An ECG is performed in the emergency department and is shown in this exhibit. 
He is admitted to the hospital and started on a diltiazem infusion.  The next morning, he continues to have a rapid pulse at 155/min.  Transthoracic echocardiogram shows left atrial dilation, normal left ventricular systolic function, and an estimated pulmonary artery systolic pressure of 50 mm Hg.
Which of the following is the best management option for this patient?

Accepted Answer

This patient's ECG shows typical type I atrial flutter with biphasic "sawtooth" flutter waves (F waves) at a rate of approximately 300/min (arrows). There is 2:1 conduction across the atrioventricular (AV) node with a ventricular rate of about 150/min. Atrial flutter can have a substantial recurrence rate, approaching 50% at 6 months in some studies. flutter waves Radiofrequency (RF) ablation has a much higher success rate and is now generally preferred over long-term antiarrhythmic drugs as the initial therapy to restore and maintain sinus rhythm in patients with typical atrial flutter. The isthmus of tissue between the inferior vena cava and tricuspid annulus (cavotricuspid isthmus) is a necessary component of the macro-reentry circuit in typical type I atrial flutter, and is the anatomic target for radiofrequency ablation. (Choice A) Adenosine is useful for acute termination of AV nodal reentrant tachycardia. However, it has no role in patients with atrial flutter. (Choice B) AV nodal blocking agents (i.e., calcium channel blockers, beta-blockers, or digoxin) are frequently used in patients with atrial flutter or fibrillation with rapid ventricular rates. In contrast to atrial fibrillation, typical atrial flutter is relatively difficult to control with pharmacologic agents. Radiofrequency ablation has emerged as a safe and effective first-line treatment option in such patients. (Choices C and E) Flecainide is a class IC antiarrhythmic agent and is occasionally used to maintain sinus rhythm in patients with paroxysmal atrial fibrillation. Sotalol is a class III antiarrhythmic agent. These drugs have marginal efficacy and a significant side effect profile. They are generally not preferred for restoring or maintaining sinus rhythm in patients with typical atrial flutter. Educational objective: Radiofrequency ablation has an excellent success rate in restoring and maintaining sinus rhythm in patients with typical atrial flutter. It is generally preferred over long-term antiarrhythmic agents as a safe and effective first-line treatment in such patients. __________ References: Diagnosis and management of typical atrial flutter. (http://www.ncbi.nlm.nih.gov/pubmed/19111764) The 1998 NASPE prospective catheter ablation registry. (http://www.ncbi.nlm.nih.gov/pubmed/10879389)

Question 7

A 38-year-old man comes to the emergency department due to 1 day of left-sided chest and neck pain.  He could not get comfortable the night before and eventually fell asleep in a semi-recumbent position.  He had a sore throat a week ago.  Medical history is also significant for acid reflux disease.
Temperature is 37.2 C (99 F), blood pressure is 132/80 mm Hg, and pulse is 90/min.  Heart sounds are normal, and lungs are clear to auscultation.  There are no skin rashes.
Laboratory results are as follows:
 ECG shows sinus rhythm with 1- to 2-mm diffuse ST-segment elevation, except for a 2-mm ST-segment depression in lead aVR.  Chest x-ray reveals normal cardiac size and clear lung fields.
Which of the following initial therapies is most likely to cause recurrent symptomatic episodes in this patient?

Accepted Answer

11ec193a_95dd_ef60_853d_194244f9e21b_MD0002_00 This patient's chest pain, characteristic ECG findings of diffuse ST elevations, and mildly elevated troponin are likely due to viral myopericarditis, defined as acute pericarditis with myocardial involvement noted with either elevated cardiac enzymes, myocarditis on cardiac MRI, or newly depressed left ventricular function. Pericarditis and myopericarditis share the same etiologies, which, in developed countries, are largely viral or idiopathic. Other causes include bacterial and fungal infections, autoimmune disease (particularly lupus), neoplasms, end-stage renal disease, and postcardiac injury (Dressler syndrome). Presenting manifestations may include pleuritic chest pain (often after viral infection), heart failure, or arrhythmias. Cardiac MRI and, in rare cases, endomyocardial biopsy may help with diagnosis. Treatment for uncomplicated myopericarditis (normal ejection fraction, no arrhythmias) mirrors that of pericarditis: Nonsteroidal anti-inflammatory drug (NSAID) therapy (eg, aspirin, indomethacin, ibuprofen) is the standard of care to control pain and reduce inflammation and should be started on all patients without contraindications (Choices A and D). In patients with postmyocardial infarction pericarditis, aspirin is the NSAID of choice as other medications may inhibit cardiac scar formation.Colchicine is recommended in conjunction with NSAIDs to improve symptoms and decrease the rate of recurrence (Choice B). Nonsteroidal anti-inflammatory drug (NSAID) therapy (eg, aspirin, indomethacin, ibuprofen) is the standard of care to control pain and reduce inflammation and should be started on all patients without contraindications (Choices A and D). In patients with postmyocardial infarction pericarditis, aspirin is the NSAID of choice as other medications may inhibit cardiac scar formation. Nonsteroidal anti-inflammatory drug (NSAID) therapy (eg, aspirin, indomethacin, ibuprofen) is the standard of care to control pain and reduce inflammation and should be started on all patients without contraindications (Choices A and D). In patients with postmyocardial infarction pericarditis, aspirin is the NSAID of choice as other medications may inhibit cardiac scar formation. Colchicine is recommended in conjunction with NSAIDs to improve symptoms and decrease the rate of recurrence (Choice B). Colchicine is recommended in conjunction with NSAIDs to improve symptoms and decrease the rate of recurrence (Choice B). This patient should receive NSAIDs and colchicine as he has contraindications to neither. By contrast, glucocorticoids, including prednisone, should be avoided as they are associated with a higher rate of recurrence and are only indicated in refractory pericarditis despite NSAID therapy, in patients in whom NSAIDs are contraindicated, or for treatment of a specific underlying cause of pericarditis (eg, autoimmune disease, connective tissue disorders, end-stage renal disease). If an underlying cause is determined, appropriate therapy (eg, antibiotics, antifungals, immunosuppressives) should be initiated. (Choice C) Intravenous immune globulin may maintain long-term remission in corticosteroid-dependent patients with recurrent episodes of pericarditis. Educational objective: Pericarditis and myopericarditis share etiologies and are typically viral or idiopathic in nature. Treatment is directed at the underlying cause, but initial treatment of pericarditis with a combination of nonsteroidal anti-inflammatory drugs (NSAIDs) and colchicine is recommended. Glucocorticoids are associated with higher rates of recurrent pericarditis and should be used only in refractory disease, in patients in whom NSAIDs are contraindicated, or for specific underlying causes. __________ References: Efficacy and safety of colchicine for pericarditis prevention. Systematic review and meta-analysis. (http://www.ncbi.nlm.nih.gov/pubmed/22442198) International collaborative systematic review of controlled clinical trials on pharmacologic treatments for acute pericarditis and its recurrences. (http://www.ncbi.nlm.nih.gov/pubmed/20934560)

Question 8

A 47-year-old man is brought to the emergency department due to lightheadedness and palpitations.  He denies chest pain, shortness of breath, or nausea.  He reports a history of palpitations since he was a teenager and says he can usually stop them by bearing down.  However, this maneuver did not work this time so he decided to come to the hospital.  His other medical problems include type 1 diabetes mellitus and hypertension.  He had a myocardial infarction 5 years ago, but has not had chest pain since then.  His exercise tolerance is good.
Blood pressure is 80/40 mm Hg and his pulse is 150/min.  Lungs are clear on auscultation.  No heart murmurs are appreciated.
ECG is shown in the exhibit. 
Which of the following is the best next step in managing this patient?

Accepted Answer

Based on ACLS guidelines, patients with any persistent tachyarrhythmia causing hemodynamic instability should have immediate synchronized cardioversion with adequate sedation and analgesia prior to cardioversion. If the patient is hemodynamically stable, the next step is to look at QRS duration to differentiate between wide complex tachycardia (WCT) and narrow complex tachycardia (NCT). Patients with NCT likely have supraventricular tachycardia (SVT) and can be treated accordingly. ACLS guidelines 11ec193a_95d9_346c_853d_8b37cf813b61_MD0002_00 Patients with WCT likely have SVT with aberrancy (due to preexisting or functional bundle branch block), antidromic AV reentrant tachycardia, or ventricular tachycardia (VT). ECG showing evidence of AV dissociation, precordial concordance, capture beats, or fusion beats favors VT and should be treated accordingly. Capture beats occur when an atrial impulse depolarizes the ventricles through the normal conduction system and causes a narrow QRS earlier than expected (circled in above ECG). This patient's ECG shows WCT with capture beats diagnostic of VT. (Choice A) Transthoracic echocardiogram should not be the initial step in patients with clinical or hemodynamic instability. It should be performed after cardioversion to assess for left ventricular function and regional wall motion abnormalities. (Choice B) Vagal maneuvers, including Valsalva or carotid sinus massage, are commonly used in stable patients to treat reentrant SVT or to distinguish between various forms of SVT. However, VT is generally unaffected by carotid sinus pressure. (Choice C) Adenosine is frequently used in the diagnosis or treatment of stable SVT. However, in patients with VT, it can cause severe hemodynamic deterioration and induce ventricular fibrillation and cardiac arrest. (Choice D) Intravenous antiarrhythmics (eg, amiodarone, procainamide) can be used in patients with stable recurrent or refractory WCT, or in cases where it is difficult to differentiate between VT and SVT with aberrancy. Synchronized cardioversion is preferred in patients with unstable WCT. Educational objective: Immediate synchronized cardioversion is the initial treatment of choice in patients with wide complex tachycardia associated with clinical and/or hemodynamic instability. __________ References: Approach to the diagnosis and initial management of the stable adult patient with a wide complex tachycardia. (http://www.ncbi.nlm.nih.gov/pubmed/18471458)

Question 9

A 72-year-old man is brought to the emergency department due to 3 days of worsening cough and shortness of breath.  The cough is productive of a small amount of white sputum.  The patient has no chest pain.  He has a history of hypertension, gout, chronic obstructive pulmonary disease, and coronary artery disease for which he underwent coronary artery bypass grafting.  He also had mitral valve repair 6 years ago.  The patient has a 40-pack-year smoking history and continues to smoke a pack of cigarettes a day.
Blood pressure is 136/72 mm Hg, pulse is 132/min, and respirations are 26/min.  Oxygen saturation is 92% on room air.  The patient appears to be in moderate respiratory distress.  Jugular venous pulse is difficult to measure due to use of accessory muscles.  Lung auscultation shows decreased air entry in both lung fields.  There is diffuse and scattered wheezing heard throughout the lung zones.  Heart sounds are irregular with a faint holosystolic murmur heard over the cardiac apex.  There is 1+ bilateral pitting ankle edema.
Laboratory results are as follows:
 ECG is shown in the exhibit. 
Which of the following is the best treatment for this patient's cardiac condition?

Accepted Answer

11ec193a_95dd_531e_853d_617b8d398ed8_MD0002_00 This patient's ECG demonstrates multifocal atrial tachycardia (MAT), a supraventricular tachyarrhythmia that most commonly occurs in elderly patients experiencing an acute exacerbation of underlying pulmonary disease. Chronic obstructive pulmonary disease (COPD) has the strongest association with MAT, but the arrhythmia is also seen with pneumonia, pulmonary embolism, and exacerbations of heart failure. Patients typically present with symptoms of the underlying illness, and the arrhythmia itself is typically asymptomatic. The diagnosis of MAT is confirmed by ECG findings of an atrial rate >100/min (tachycardia differentiates MAT from wandering atrial pacemaker), irregular R-R intervals, and distinct P waves with >3 different morphologies. Treatment is aimed at the inciting disturbance (eg, systemic corticosteroids and inhaled bronchodilators for this patient's COPD exacerbation). ECG findings Other potential causes of MAT include electrolyte imbalance (eg, hypokalemia, hypomagnesemia) and nonpulmonary conditions that lead to catecholamine surge (eg, sepsis). (Choice A) Rate control with a cardiac glycoside (eg, digoxin) or other agent that slows atrioventricular conduction (eg, beta blocker, nondihydropyridine calcium channel blocker) is sometimes useful in case of persistent MAT despite treatment of the inciting disturbance or in case of hemodynamic instability as a result of MAT (rare). However, this rarely leads to resolution of MAT. (Choice C) Electrical cardioversion is not effective in converting MAT to sinus rhythm and is not recommended. (Choices D and E) Antiarrhythmic drugs (eg, amiodarone, ibutilide) are often used for pharmacological cardioversion in patients with atrial fibrillation but are ineffective in the management of MAT. Educational objective: Multifocal atrial tachycardia most commonly occurs in elderly patients with an exacerbation of underlying pulmonary disease (eg, chronic obstructive pulmonary disease), and is characterized by ECG showing an atrial rate >100/min, irregular R-R intervals, and >3 distinct P wave morphologies. Treatment is aimed at correcting the underlying inciting disturbance. __________ References: Multifocal atrial tachycardia. (http://www.ncbi.nlm.nih.gov/pubmed/9440591)

Question 10

A 76-year-old man is seen in the emergency department with cough and worsening dyspnea over the last 2 days. He awoke suddenly last night gasping for air and could not get comfortable in any position. He has no fever or chills. The patient's other medical problems include hypertension and type 2 diabetes mellitus. He has a 40-pack-year smoking history and drinks beer occasionally. His temperature is 37.2° C (99° F), blood pressure is 150/90 mm Hg, pulse is 106/min, and respirations are 25/min. Pulse oximetry is 94% on 2 L O₂. Body mass index is 35 kg/m². Jugular venous pressure is measured at 12 cm H₂O. He appears in mild respiratory distress. Heart sounds are distant but no murmurs are heard. Lung examination shows bibasilar crackles and scattered bilateral wheezes. There is 1+ pitting ankle edema seen bilaterally. Laboratory results are as follows: Chest x-ray reveals prominent vascular markings and blunting of costophrenic angles. Echocardiogram shows a diffusely hypokinetic left ventricle with ejection fraction of 35%. Which of the following best explains the normal brain natriuretic peptide value?

Accepted Answer

Brain natriuretic peptide (BNP) is a natriuretic hormone cleaved from the prohormone N-terminal pro-BNP (NT-proBNP) and released from ventricles in response to increased ventricular filling pressures. Elevated BNP and NT-proBNP can help diagnose both heart failure and asymptomatic and symptomatic left ventricular dysfunction. However, both hormones may be elevated in conditions that increase ventricular pressures and present with dyspnea (eg, cor pulmonale, pulmonary embolism, pulmonary hypertension). BNP < 100 pg/mL and NT-proBNP < 300 pg/mL are highly predictive for excluding heart failure, and these patients require evaluation for noncardiac causes of dyspnea. BNP > 400 pg/mL and NT-proBNP > 900 pg/mL are accurate for diagnosing heart failure. Levels in between are not as specific or sensitive for diagnosing or excluding heart failure. In addition, the hormones are not as useful in distinguishing between systolic and diastolic failure. Both hormones may be increased in chronic kidney disease due to decreased renal clearance of NT-proBNP. Higher hormone levels are also seen in patients age > 65 (Choice E). Obese patients have lower BNP and NT-proBNP levels than nonobese patients for unclear reasons. As a result, low hormone levels should be interpreted with caution in these patients. This obese patient has a lower BNP than expected despite his clinical picture being typical and diagnostic of heart failure (Choice D). (Choice B) There is no correlation between hypertension and decreased BNP levels. (Choice C) Hyponatremia seen in conjunction with elevated BNP in heart failure is usually due to water reabsorption from increased antidiuretic hormone, renin, and norepinephrine. This indicates poor prognosis. Educational objective: BNP < 100 pg/mL and NT-proBNP < 300 pg/mL are highly predictive for excluding heart failure, and BNP > 400 pg/mL and NT-proBNP > 900 pg/mL are accurate for diagnosing heart failure. Higher hormone levels are found in older individuals and those with chronic kidney disease. Lower hormone levels are seen in obese patients and should be interpreted with caution. __________ References: Updating the role of natriuretic peptide levels in cardiovascular disease. (http://www.ncbi.nlm.nih.gov/pubmed/22104459) The paradox of low BNP levels in obesity. (http://www.ncbi.nlm.nih.gov/pubmed/21523383) Impact of body mass and body composition on circulating levels of natriuretic peptides: results from the Dallas Heart Study. (http://www.ncbi.nlm.nih.gov/pubmed/16203929)

Question 11

A 73-year-old woman comes to the emergency department due to vision changes. Over the last few days, she has noticed blurred vision and scattered blind spots while watching television. She reports poor appetite and fatigue since an episode of gastroenteritis 2 weeks ago. She has no fever, headache, or muscle weakness but admits feeling unsteady. Her past medical history is significant for hypertension, type 2 diabetes mellitus, heart failure with reduced ejection fraction (ejection fraction of 15%), and mild chronic obstructive lung disease. Her medications include tiotropium, torsemide, ramipril, carvedilol, spironolactone, digoxin, and empagliflozin. The patient is adherent with her medications and clinic visits. She is a former smoker with a 35-pack-year history. Her blood pressure is 144/90 mm Hg supine and 140/90 mm Hg standing. Pulse is 52/min in both positions. BMI is 19 kg/m². The mucous membranes appear dry. Lungs are clear to auscultation and no murmurs are heard on cardiac examination. There is mild epigastric tenderness on deep palpation. There is no peripheral edema. Neurologic examination is unremarkable except for mild unsteady gait. Fingerstick glucose is 109 mg/dL. Which of the following is the most likely diagnosis?

Accepted Answer

This patient's clinical presentation suggests digoxin toxicity, likely precipitated by recent gastroenteritis. Digoxin has a narrow therapeutic range (0.8-2.0 ng/mL; range of 0.5-0.8 ng/mL recommended in heart failure) and is cleared by the kidneys. Recent illnesses (eg, gastroenteritis) can lead to volume depletion and/or acute kidney injury with impaired digoxin clearance. Other potentiating factors include hypokalemia, hypomagnesemia, hypercalcemia, and myocardial ischemia. Acute digoxin toxicity presents with significant anorexia, nausea, vomiting, abdominal pain (possible nonocclusive mesenteric ischemia), confusion, and weakness. Chronic digoxin toxicity occurs gradually and presents with less pronounced gastrointestinal symptoms but more significant neurologic symptoms (eg, lethargy, fatigue, delirium, confusion, disorientation, weakness) and visual symptoms (eg, changes in color vision, blurred vision, scotomas, blindness). Digoxin toxicity can cause a wide range of cardiac arrhythmias including atrial tachycardia, atrioventricular block, and ventricular tachycardia. (Choice A) Acute angle-closure glaucoma usually presents with red eye, decreased peripheral vision, light-halos, headache, severe eye pain, nausea, and vomiting. (Choice B) Chronic heart failure may present with weight loss and symptoms of anorexia, early satiety, and depression. Although this patient may also have cardiac cachexia, her visual and gastrointestinal symptoms are more suggestive of digoxin toxicity. (Choice C) Symptoms of cerebellar stroke include headache, vertigo, nystagmus, vomiting, gait ataxia, and limb incoordination. Although this patient has a mild unsteady gait, she does not have the other symptoms. (Choice D) Patients with diabetic retinopathy are asymptomatic for years and may present with blurred vision, partial or total loss of vision, and floaters. Those with good glycemic control (such as this patient) are less likely to develop diabetic retinopathy complications. Educational objective: Digoxin toxicity can be precipitated by recent illness that causes volume depletion or by drugs that impair renal clearance of digoxin. Patients usually present with gastrointestinal disturbances, neurologic dysfunction, vision changes, electrolyte imbalances, and cardiac arrhythmias. __________ References: Mechanisms, manifestations, and management of digoxin toxicity in the modern era. (http://www.ncbi.nlm.nih.gov/pubmed/16555861)

Question 12

A 67-year-old woman comes to the emergency department with swelling of her right eyelid and lips.  The swelling started an hour earlier and increased slowly until she became alarmed.  She reports no trouble breathing and has had no abdominal pain.  There is no associated itching or rash.  Her past medical history includes congestive heart failure due to nonischemic cardiomyopathy, hypertension, hyperlipidemia, and osteoporosis.  The patient's last left ventricular ejection fraction was 38%.  She is able to walk 3-4 blocks without shortness of breath.  Her current medications include furosemide, ramipril, simvastatin, and metoprolol succinate.  There is no family history of similar occurrences.
The patient's blood pressure is 130/80 mm Hg, pulse is 72/min, and respirations are 14/min.  Pulse oximetry is 98% on room air.  There is non-pitting edema of her right eyelid and upper and lower lips.  Cardiac examination reveals a 2/6 holosystolic murmur at the apex.  There is no stridor and lung examination is normal.  The remainder of the examination is within normal limits.
After observation and recovery, which of the following would be the best therapeutic option for this patient?

Accepted Answer

This patient presents with angioedema likely due to angiotensin-converting enzyme (ACE) inhibitor. ACE inhibitors can cause angioedema in about 0.5% of patients. It can occur at any time during treatment and is not dependent on the dosage or type of ACE inhibitor used. Risk factors include African descent, female gender, smoking, and use of nonsteroidal anti-inflammatory drugs. The angioedema affects mainly the lips, tongue, face, and upper airways. Less commonly, it may affect the intestines, resulting in abdominal pain with ascites. There is no itching or urticaria. When the upper airways are affected, hoarseness and stridor can occur and lead to respiratory failure (in about 10% of cases). ACE inhibitor angioedema is due to elevated levels of bradykinin. Antihistamines, glucocorticoids, and epinephrine are frequently used to treat allergic angioedema (histamine-induced). These agents are not very effective in treating ACE inhibitor-induced angioedema but are frequently used for this purpose. Fresh frozen plasma may be used as it contains the enzyme ACE, which degrades bradykinin, leading to faster clinical improvement of angioedema. Patients who develop ACE inhibitor-induced angioedema should avoid all ACE inhibitors as the angioedema is not dependent on the dosage or type used. Those who require the cardioprotective effects of ACE inhibitors can be switched to angiotensin II receptor blockers (ARBs). However, some studies have shown a 1.5%-10% recurrence rate of angioedema in patients who were switched to ARBs. This effect is usually seen within 1 month of discontinuation of ACE inhibitors, suggesting a residual effect of ACE inhibitor-induced angioedema rather than the result of ARB use. Thus, a safe alternate strategy is to wait 4 weeks before switching patients to ARBs under close monitoring. (Choice C) Although direct renin inhibitors such as aliskiren have no known effects on bradykinin metabolism, several studies have shown angioedema with their use. Until these drugs are more widely used, they are not advisable as alternate therapy to ACE inhibitors in patients with known previous angioedema. Educational objective: Angiotensin-converting enzyme (ACE) inhibitor-induced angioedema can occur at any time during treatment and is not dependent on the dosage or type of ACE inhibitor used. Treatment includes discontinuation of the drug and supportive care. Patients who require the cardioprotective effect of ACE inhibitors can be switched safely to angiotensin II receptor blockers with close monitoring. __________ References: Comparative risk for angioedema associated with the use of drugs that target the renin-angiotensin-aldosterone system. (http://www.ncbi.nlm.nih.gov/pubmed/23147456) Multicenter study of patients with angiotensin-converting enzyme inhibitor-induced angioedema who present to the emergency department. (http://www.ncbi.nlm.nih.gov/pubmed/18450117) Epidemiological study of angioedema and ACE inhibitors. (http://www.ncbi.nlm.nih.gov/pubmed/9028507)

Question 13

A 61-year-old man comes to the emergency department complaining of nausea and right upper-quadrant abdominal discomfort for 3 days.  His other medical problems include hypertension, type 2 diabetes, hypercholesterolemia, and hypothyroidism.  His medications include low-dose aspirin, metformin, glipizide, hydrochlorothiazide, lisinopril, atorvastatin, and levothyroxine.  He is an active smoker with a 60-pack-year history and drinks 1-2 glasses of wine daily.
His blood pressure is 155/90 mm Hg and pulse is 80/min.  Examination shows no abnormalities.
Laboratory results are as follows:

Ultrasound examination shows several small gallstones without cholecystitis and a 3.8-cm abdominal aortic aneurysm.
Which of the following is associated with the highest rate of aneurysm expansion and rupture in this patient?

Accepted Answer

Abdominal aortic aneurysms (AAAs) are usually asymptomatic and are found incidentally on imaging studies done for unrelated reasons. Risk factors associated with AAA development include age > 60, male gender, cigarette smoking, white race, atherosclerosis, and family history of AAA. The diameter can increase progressively and lead to potentially life-threatening rapid aneurysmal expansion and rupture. The major risk factors associated with aneurysmal expansion and rupture include large diameter (> 5.5 cm), expansion rate of > 0.5 cm every 6 months or > 1 cm per year, and active cigarette smoking. Active smoking is associated with the highest rate of aneurysmal expansion and rupture. The mechanism is unclear but likely involves connective tissue degeneration in the aortic wall. Elective repair is preferred for prevention of AAA rupture. Due to operative risk, repair is usually not recommended in asymptomatic patients until the aneurysm diameter is > 5.5 cm (when the risk of rupture exceeds risks of repair). (Choice B & C) Chronic kidney disease and alcohol consumption are not associated with risk of aneurysmal dilation and rupture. (Choice D) Hyperlipidemia is an important modifiable risk factor in patients with atherosclerosis but has not been associated with increased risk for aneurysmal growth and expansion. Statin use has not been shown to reduce the rate of AAA expansion in multiple studies. (Choice E) Diabetes is a strong risk factor for atherosclerosis. However, diabetes mellitus is actually associated with a decreased risk for developing an AAA or expansion of an existing AAA. Educational objective: Observational studies have shown that the strongest predictors of abdominal aortic aneurysm (AAA) expansion and rupture are large aneurysm diameter, rapid rate of expansion, and active cigarette smoking. Active cigarette smoking is associated with the highest rate of aneurysmal expansion and rupture. Referral for AAA repair is recommended for asymptomatic patients with aneurysmal diameter > 5.5 cm. __________ References: Analysis of risk factors for abdominal aortic aneurysm in a cohort of more than 3 million individuals. (http://www.ncbi.nlm.nih.gov/pubmed/20630687) Abdominal aortic aneurysm expansion: risk factors and time intervals for surveillance. (http://www.ncbi.nlm.nih.gov/pubmed/15210603)

Question 14

A 42-year-old woman comes to the emergency department with fever and a skin rash. She was diagnosed with trigeminal neuralgia and started on carbamazepine 3 weeks ago. The patient's temperature is 38.9 C (102 F). There is diffuse confluent erythema involving 60% of the body, palpable generalized lymphadenopathy, and symmetrical facial swelling. There are no mucosal lesions. Her aspartate aminotransferase level is 150 U/L, eosinophil count is 800/mm³, and serum creatinine is 0.9 mg/dL. Which of the following is the most likely diagnosis?

Accepted Answer

This patient's fever and skin rash after starting a new medication suggest drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome. DRESS is a potentially life-threatening drug reaction typically occurring 2-8 weeks after initial exposure. Commonly associated drugs include anticonvulsants (eg, phenytoin, carbamazepine), allopurinol, sulfonamides (eg, sulfasalazine), and antibiotics (eg, minocycline, vancomycin). Patients typically develop fever, generalized lymphadenopathy, facial edema, and a diffuse morbilliform skin rash that can progress to a confluent erythema with follicular accentuation. The rash can involve the mucosa (eg, mouth, pharynx) but does not cause erosions. Other affected organs can include the liver (hepatomegaly, jaundice), kidney (acute interstitial nephritis), and lung (cough, dyspnea). Laboratory results show eosinophilia, atypical lymphocytosis, and elevated hepatic transaminases. Clinical findings usually improve with supportive care and stopping the drug, but resolution can take up to 6-9 weeks. skin rash (Choice A) Hypersensitivity vasculitis is characterized by fever, skin findings (palpable purpura, petechiae), arthralgias, lymphadenopathy, and elevated erythrocyte sedimentation rate. It is frequently associated with anticonvulsants, but there is usually no significant eosinophilia. (Choice C) Hypereosinophilic syndrome (HES) is characterized by profound eosinophilia (>1500/mm³) and multisystem involvement (eg, heart, gastrointestinal tract, lungs, brain, skin, kidneys) without an identifiable etiology. This patient's eosinophil count does not meet the criteria for HES. ³ (Choice D) Serum sickness-like syndrome can occur after exposure to drugs (often antiseizure drugs or antibiotics) or infections (eg, hepatitis B, Streptococcus) and causes systemic symptoms, arthralgias, and an urticarial or serpiginous macular rash. However, the reaction usually occurs within 1-2 weeks of drug exposure and does not cause significant eosinophilia. (Choice E) Stevens-Johnson syndrome is often triggered by exposure to new medications and is characterized by sudden-onset mucocutaneous lesions with subsequent necrosis and sloughing. However, mucosal involvement is usually prominent, and it does not cause eosinophilia or significantly elevated liver enzymes. Educational objective: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome occurs 2-8 weeks after exposure to a new drug (eg, anticonvulsants, allopurinol, antibiotics). It is characterized by fever, lymphadenopathy, facial edema, diffuse morbilliform skin rash, eosinophilia, and elevated hepatic transaminases. __________ References: Drug reaction with eosinophilia and systemic symptoms (DRESS): an original multisystem adverse drug reaction. Results from the prospective RegiSCAR study. (http://www.ncbi.nlm.nih.gov/pubmed/23855313) The DRESS syndrome: a literature review. (http://www.ncbi.nlm.nih.gov/pubmed/21592453)

Question 15

A 62-year-old man comes to the emergency department due to sudden-onset chest pain.  The patient is diagnosed with unstable angina.  He undergoes cardiac catheterization and receives a drug-eluting stent to the left circumflex artery.  Medical issues include hypertension, hypercholesterolemia, osteoarthritis, and chronic kidney disease.  The patient was hospitalized 6 months earlier for upper gastrointestinal bleeding related to ibuprofen use.  He is treated with aspirin, prasugrel, lisinopril, atorvastatin, and metoprolol.
Laboratory results are as follows:
 Echocardiogram shows a left ventricular ejection fraction of 55%.  Which of the following additional therapies is indicated in this patient?

Accepted Answer

Dual antiplatelet therapy (DAPT) (aspirin plus P2Y₁₂ receptor blocker) to prevent stent thrombosis following recent drug-eluting stent placement increases the risk of gastrointestinal bleeding (GIB). This risk is particularly increased among patients with peptic ulcer disease, prior upper GIB, active Helicobacter pylori infection, or age >65. ₁₂ In high-risk patients taking DAPT, proton pump inhibitor (PPI) therapy should be initiated as it significantly decreases the risk of upper GIB. PPI inhibition of CYP219 metabolism may decrease the efficacy of the P2Y₁₂ receptor blocker clopidogrel in preventing stent thrombosis; therefore, when clopidogrel is used, PPIs with relatively strong CYP219 inhibition (eg, omeprazole) should be avoided in favor of those with weaker CYP219 inhibition (eg, pantoprazole). PPI therapy does not appear to affect the efficacy of prasugrel and other P2Y₁₂ receptor blockers (eg, ticagrelor). ₁₂ ₁₂ (Choice A) ACE inhibitor (eg, lisinopril) monotherapy and angiotensin II receptor blocker (ARB) monotherapy have both been shown to reduce proteinuria and slow the progression of chronic kidney disease. This patient is already on lisinopril, and adding an ARB to an ACE inhibitor is not recommended due to unclear additional benefit and an increased risk of adverse effects (eg, hyperkalemia, acute kidney injury). (Choice B) Although niacin can significantly raise serum HDL levels, there is no evidence that the addition of niacin to a statin improves cardiovascular outcomes compared with statin therapy alone. (Choice D) Ranolazine is an antianginal agent typically reserved for stable angina that is refractory to other medical therapy (eg, beta blockers, calcium channel blockers, nitrates) and/or coronary revascularization. It is not currently indicated in this patient. (Choice E) Spironolactone is an aldosterone antagonist indicated for patients with symptomatic heart failure with left ventricular ejection fraction <35%. It is not indicated in this patient with normal left ventricular systolic function. < Educational objective: Prior upper gastrointestinal bleeding (GIB), peptic ulcer disease, active Helicobacter pylori infection, and age >65 increase the risk of upper GIB in patients taking dual antiplatelet therapy (DAPT). Proton pump inhibitor therapy has been shown to decrease the risk of upper GIB in high-risk patients taking DAPT. __________ References: Clopidogrel with or without omeprazole in coronary artery disease. (http://www.ncbi.nlm.nih.gov/pubmed/20925534) ACCF/ACG/AHA 2010 expert consensus document on the concomitant use of proton pump inhibitors and thienopyridines: a focused update of the ACCF/ACG/AHA 2008 expert consensus document on reducing the gastrointestinal risks of antiplatelet therapy and NSAID use: a report of the American College of Cardiology Foundation Task Force on expert consensus documents. (http://www.ncbi.nlm.nih.gov/pubmed/21060077) Expert position paper on the use of proton pump inhibitors in patients with cardiovascular disease and antithrombotic therapy. (http://www.ncbi.nlm.nih.gov/pubmed/23425521)

Question 16

A 42-year-old man comes to the emergency department due to fatigue, chest pain, and shortness of breath for the past 5 days. He has had difficulty falling asleep at night due to chest discomfort. The patient had a "bad case of the flu" 3 weeks ago and still has a persistent cough. He is otherwise healthy and has no other medical problems. He has a 20-pack-year smoking history and drinks 3 or 4 beers on weekends. Blood pressure is 92/54 mm Hg and pulse is 112/min. Blood pressure decreases to 75/42 mm Hg during inspiration. Jugular venous pressure is estimated at 16 cm H₂O. There are minimal crackles present at both lung bases. Heart sounds are faint on cardiac auscultation. Lower extremities are cool with feeble pulses. Chest x-ray is shown in the exhibit. An echocardiogram in this patient would most likely show which of the following?

Accepted Answer

This patient's clinical presentation is consistent with viral pericarditis complicated by pericardial effusion and subacute cardiac tamponade. He has many of the classic clinical features of cardiac tamponade (including muffled heart sounds, hypotension with pulsus paradoxus, and elevated jugular venous pressure), and chest x-ray reveals classic "water bottle" heart indicating pericardial effusion. Transthoracic echocardiogram is useful for determining the size of the pericardial effusion and for identifying early signs of cardiac tamponade before overt hemodynamic collapse occurs. Accumulation of fluid in the pericardial cavity leads to an increase in intrapericardial pressure, and collapse of right-sided cardiac chambers occurs when the pressure within these cardiac chambers is exceeded. The right atrium has the lowest pressure of all cardiac chambers; therefore, right atrial collapse during end diastole is the earliest and most sensitive sign of cardiac tamponade. Right ventricular diastolic collapse is less sensitive than right atrial diastolic collapse, but is highly specific for the presence of cardiac tamponade. right atrial collapse (Choice A) Dynamic left ventricular outflow obstruction is seen in hypertrophic cardiomyopathy, for which pulsus paradoxus is not an expected finding. (Choice B) Global left ventricular hypokinesis is seen in patients with idiopathic cardiomyopathy, and can also occur in acute or subacute viral myocarditis. However, this patient has minimal pulmonary crackles, muffled heart sounds, and pulsus paradoxus, suggesting cardiac tamponade. The left ventricle is usually hyperkinetic in patients with cardiac tamponade. (Choice C) The left ventricle is more muscular and has higher cavity pressure than the right-sided heart chambers; as a result, left ventricular chamber collapse is seen in only a minority of patients with cardiac tamponade. When present, the finding is highly specific for tamponade. (Choice E) Right ventricular dilation and free wall hypokinesia with sparing of the apex (McConnell sign) can occur in patients with acute pulmonary embolism, with one study demonstrating 77% sensitivity and 94% specificity. Acute pulmonary embolism is less likely in this patient given the muffled heart sounds and "water bottle" sign on chest x-ray. McConnell sign Educational objective: Right atrial collapse during end diastole is the earliest and most sensitive echocardiographic sign of cardiac tamponade. Right ventricular diastolic collapse is less sensitive than right atrial diastolic collapse but is highly specific for cardiac tamponade. __________ References: Frequency and significance of chamber collapses during cardiac tamponade. (http://www.ncbi.nlm.nih.gov/pubmed/2330872) Hydrodynamic compression of the right atrium: a new echocardiographic sign of cardiac tamponade. (http://www.ncbi.nlm.nih.gov/pubmed/6861307)

Question 17

A 62-year-old man comes to the emergency department with 2 episodes of retrosternal pressure-like chest pain over the last 6 hours.  Medical history is significant for type 2 diabetes mellitus, hypertension, and end-stage renal disease.  He undergoes hemodialysis 3 times a week through a left arm arteriovenous fistula.
Blood pressure is 152/89 mm Hg and pulse is 88/min.  The chest is clear on auscultation.  There are no heart murmurs.
Bedside finger-stick glucose level is 134 mg/dL.  ECG shows normal sinus rhythm with 1-mm horizontal ST-segment depressions in leads II, III, aVF, and V4-V6.  The initial troponin I level is 1.5 ng/mL (normal: <0.01).
He is treated with aspirin.
Which of the following is the most appropriate additional treatment for this patient?

Accepted Answer

This patient's clinical presentation - recurrent substernal chest pain, ST-segment depression, and elevated cardiac biomarkers - is consistent with non-ST elevation myocardial infarction (NSTEMI). The acute pharmacologic management of unstable angina/NSTEMI in patients with end-stage renal disease (ESRD) is similar to that in other patients. In the absence of specific contraindications, patients who have ESRD with NSTEMI should receive aspirin, a P2Y₁₂ receptor blocker (eg, clopidogrel), a beta blocker, and anticoagulation therapy. Nitrates may also be given for active chest pain. The benefit of high-intensity statin (eg, atorvastatin) therapy is not clear in patients with ESRD. ₁₂ This patient has no contraindication to beta blocker use (eg, decompensated heart failure, bradycardia) and should be started on metoprolol to reduce infarct size and lower the risk of reinfarction and early mortality. (Choices A and E) Calcium channel blockers (eg, amlodipine) and aldosterone antagonists (eg, spironolactone) are not indicated in the acute management of unstable angina/NSTEMI. (Choice B) Anticoagulant therapy is indicated for patients with unstable angina/NSTEMI. However, enoxaparin, a low-molecular-weight heparin, is renally cleared and is not recommended in patients with ESRD due to increased risk of bleeding complications. Anticoagulation with unfractionated heparin is more appropriate in patients with ESRD. (Choice C) Glycoprotein IIb/IIIa inhibitors are sometimes used in acute coronary syndrome at the time of percutaneous coronary intervention if there is heavy clot burden or high-risk features (eg, elevated troponin). However, in patients with ESRD, their use is associated with increased risk of bleeding complications; abciximab is preferred (no renal dosing adjustment required) whereas eptifibatide is contraindicated. Educational objective: Patients with unstable angina/non-ST elevation myocardial infarction and end-stage renal disease (ESRD) should be managed with pharmacologic therapy similar to that for patients without renal failure. However, enoxaparin and the glycoprotein IIb/IIIa inhibitor eptifibatide are contraindicated in patients with ESRD. __________ References: Contraindicated medication use in dialysis patients undergoing percutaneous coronary intervention. (http://www.ncbi.nlm.nih.gov/pubmed/19996401) 2012 ACCF/AHA focused update of the guideline for the management of patients with unstable angina/non-ST-elevation myocardial infarction (updating the 2007 guideline and replacing the 2011 focused update): a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/22800849)

Question 18

A 54-year-old man comes to the emergency department with severe chest and neck pain that started 2 hours ago.  His past medical history is significant for hypertension treated with amlodipine and irbesartan.  His father died suddenly at the age of 43 years.  He does not smoke or use illicit drugs.
His blood pressure is 162/100 mmHg and pulse is 101/min.  He appears mildly uncomfortable due to pain.
EKG shows sinus tachycardia, voltage criteria for left ventricular hypertrophy, and T wave inversions in leads V5 and V6.  Chest x-ray findings are shown below.

He is initially treated with nitroglycerin.
What is the best next step in managing this patient?

Accepted Answer

11ec193a_95e5_4267_853d_f1279e046145_MD0002_00 This patient presents with hypertension, anterior chest pain and neck pain with widening of the mediastinum on chest x-ray suggestive of acute aortic dissection involving the ascending aorta. Descending aortic dissections present more frequently with back pain. Neck pain may suggest coronary artery ischemia due to occlusion by dissecting flap. This patient has T wave inversions which may suggest myocardial ischemia or could be secondary repolarization changes from left ventricular hypertrophy. Since anticoagulation is contraindicated in acute aortic dissection, the diagnosis needs to be excluded before treating with antiplatelet agents or anticoagulants (Choice A) for suspected myocardial ischemia. These agents may increase the risk of hemothorax and hemopericardium in aortic dissection. Ascending aortic dissection is considered a surgical emergency with reported mortality rate of 1 to 2% per hour after the onset of symptoms. Chest radiography has limited diagnostic sensitivity and specificity as patients with tortuous aorta may also have a widened mediastinum. Rapid confirmation can be obtained by chest CT angiogram (CTA). It has high sensitivity and specificity for identification of intimal flap. TEE is preferred in patients with renal insufficiency or contrast allergy. intimal flap (Choice B) There is no indication for urgent cardiac catheterization (no ST elevations or new left bundle branch block) in this case and it may further delay care. (Choice C) Chest tube insertion is indicated in patients with pneumothorax, hemothorax or large pleural effusions, which are readily identified on chest radiography. (Choice E) A repeat EKG and serial cardiac enzyme measurements would be appropriate once the possibility of aortic dissection has been definitively ruled out. Educational objective: Chest pain associated with hypertension and a widened mediastinum is suggestive of thoracic aortic dissection which has high mortality. Timely diagnosis with chest computed tomography angiogram is essential before treating other causes of chest pain. TEE is preferred in patients with renal insufficiency. __________ References: Diagnosis and management of acute aortic syndromes: dissection, intramural hematoma, and penetrating aortic ulcer penetrating aortic penetrating aortic ulcer. (http://www.ncbi.nlm.nih.gov/pubmed/25156302) The role of imaging in aortic dissection and related syndromes. (http://www.ncbi.nlm.nih.gov/pubmed/24742892)

Question 19

A 54-year-old man comes to the emergency department due to several hours of left upper quadrant pain, which is constant and worsens with deep inspiration.  The patient came to the emergency department a week ago due to fatigue and low-grade fevers for the past month.  Blood cell counts, chest x-ray, and urinalysis were within normal limits, and the patient was discharged home with symptomatic treatment.  He has had no cough, shortness of breath, vomiting, or diarrhea but reports a 4.5-kg (10-lb) weight loss over the past month.  Medical history includes hypertension, osteoarthritis, and a "heart murmur."  The patient is a smoker with a 30-pack-year history, drinks alcohol occasionally, and does not use illicit drugs.  He is a livestock farmer in rural Pennsylvania and recently returned from a hunting trip.
Temperature is 38.4 C (101.1 F), blood pressure is 136/72 mm Hg, pulse is 90/min, and respirations are 16/min.  The lungs are clear on auscultation.  Heart sounds are normal, and a 2/6 early diastolic murmur is present at the right upper sternal border.  The abdomen is tender in the left upper quadrant with no guarding or rebound tenderness.
Laboratory results are as follows:
 ECG shows sinus rhythm with nonspecific ST- and T-wave changes.  CT scan of the abdomen reveals multiple splenic infarcts.  Three sets of blood cultures obtained during the previous emergency department visit reveal no growth.  Which of the following is the best next step in management of this patient?

Accepted Answer

11ec193a_95e8_018b_853d_711ae06df352_MD0002_00 This patient has multiple findings to suggest subacute infective endocarditis (ie, fatigue, low-grade fevers, splenic infarcts, murmur of aortic regurgitation). No growth on 3 sets of blood cultures after ≥7 days is consistent with culture-negative endocarditis (CNE), which suggests fungi or fastidious bacteria (eg, Coxiella burnetii, Bartonella spp, Tropheryma whippelii) as the most likely organism. HACEK bacteria are relatively easily detected by modern culture methods and are no longer considered a common cause of CNE. HACEK In a large epidemiologic study of CNE, C burnetii was the most common organism identified; it is typically contracted by droplet exposure from infected livestock. Acute infection manifests as Q fever, which typically consists of pneumonia with flu-like symptoms and hepatitis but can be asymptomatic. Infective endocarditis can occur several months following acute infection; it is seen primarily in men age >40, pregnant women, and patients with underlying valvular pathology. The modified Duke criteria are used for diagnosis; positive Q fever serology (IgG antibody titer >1:800) is considered a major clinical criterion. Initial diagnostic evaluation should include transthoracic or transesophageal echocardiography to identify valvular vegetations and perivalvular lesions. Positron emission tomography may also be helpful in suggesting infectious valvular pathology. modified Duke criteria (Choices A and D) Systemic lupus erythematosus and malignancy are potential causes of nonbacterial thrombotic endocarditis (valvular deposition of sterile platelet thrombi). However, fever and a heart murmur are uncommon in nonbacterial thrombotic endocarditis, and systemic embolization (eg, stroke) is the more typical initial presentation. (Choice B) Intracytoplasmic inclusions (morulae) are seen in ehrlichiosis, a tick-borne illness common in the southeastern and mid-Atlantic United States. Patients typically have fever accompanied by fatigue, arthralgias, headaches, and splenomegaly. However, leukopenia and thrombocytopenia are typically present, making the diagnosis less likely in this patient. (Choice E) Inherited thrombophilia (eg, factor V Leiden, protein C or S deficiency) may cause splenic infarction, often with associated fever. However, this patient has been having fevers for a month, and an inherited thrombophilia would not explain a regurgitant murmur. Educational objective: Coxiella burnetii causes Q fever and is one of the most common causes of culture-negative endocarditis. The initial evaluation of patients with suspected Q-fever endocarditis should include transthoracic or transesophageal echocardiography to identify valvular vegetations. __________ References: Comprehensive diagnostic strategy for blood culture-negative endocarditis: a prospective study of 819 new cases. (http://www.ncbi.nlm.nih.gov/pubmed/20540619) Infective endocarditis in adults: diagnosis, antimicrobial therapy, and management of complications: a scientific statement for healthcare professionals from the American Heart Association. (http://www.ncbi.nlm.nih.gov/pubmed/26373316)

Question 20

A 62-year-old man comes to the emergency department due to 2 hours of chest discomfort. He was eating a light dinner when he developed rapidly worsening mid-chest discomfort associated with nausea and weakness. For the last few days, the patient has also experienced "stomach flu" symptoms with episodic nausea and vomiting and decreased oral intake. Two weeks ago, he was diagnosed with an acute inferior wall myocardial infarction and received a bare metal stent to the right coronary artery. His hospital course was uncomplicated. Pre-discharge echocardiogram showed inferior and posterior wall hypokinesis and a left ventricular ejection fraction of 50%. Temperature is 37.2 C (99 F), blood pressure is 98/64 mm Hg, and pulse is 55/min. Oxygen saturation is 99% on room air. BMI is 23 kg/m². The patient appears uncomfortable. There is no jugular venous distention and the lungs are clear. A grade 2/6 holosystolic murmur is heard at the apex. The abdomen is nontender with no hepatomegaly. Peripheral pulses are symmetric. ECG shows sinus bradycardia with 2-mm ST-segment elevation in leads II, III, and aVF. Which of the following is the most likely diagnosis?

Accepted Answer

This patient is experiencing an acute inferior wall myocardial infarction (MI) due to coronary artery stent thrombosis. Stent thrombosis is most common in the first month following stent placement but may develop at any time. It typically presents as an ST elevation MI and carries a mortality rate of up to 30%. Dual antiplatelet therapy (DAPT) with aspirin and a platelet P2Y12 receptor blocker (eg, clopidogrel, prasugrel, ticagrelor) is recommended for at least 6-12 months following placement of either drug-eluting or bare metal stents (BMS). If necessary, treatment can be limited to 1 month following BMS placement in patients with high bleeding risk, impaired compliance, or planned surgical procedures. Premature discontinuation of DAPT is the most important factor associated with stent thrombosis. This patient's gastroenteritis likely precluded his ability to tolerate DAPT only 2 weeks after BMS placement, placing him at high risk for stent thrombosis. (Choice A) Left ventricular aneurysm represents scarred myocardium due to prior MI. It can cause progressive left ventricular enlargement leading to heart failure, angina, arrhythmias, or mural thrombus embolization. ECG shows persistent ST-segment elevation due to dyskinetic myocardial segments, along with deep Q waves in the same leads (not seen in this patient). (Choice B) This patient has clear evidence of acute myocardial injury on ECG, and his symptoms should not be attributed to noncardiac pain. (Choice C) Some degree of mitral regurgitation (holosystolic murmur at apex) can occur in patients with inferior MI due to papillary muscle dysfunction and/or tethering of posterior mitral leaflet. Papillary muscle rupture typically occurs within 3-5 days after an acute MI, leading to acute severe mitral regurgitation with hypotension and pulmonary edema. The patient has clear lung fields and is not markedly hypotensive, making papillary rupture unlikely. (Choice D) Peri-infarction pericarditis generally occurs within days after acute MI. It is characterized by pleuritic chest pain, a pericardial friction rub, and diffuse ST elevations on ECG. Educational objective: Stent thrombosis typically presents as an ST elevation myocardial infarction, usually within the first month after stent placement. Premature discontinuation of antiplatelet therapy is the most important factor associated with stent thrombosis. __________ References: Stent thrombosis. (http://www.ncbi.nlm.nih.gov/pubmed/20946992) 2014 ACC/AHA guideline focused update on duration of dual antiplatelet therapy in patients with coronary artery disease: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. (http://www.ncbi.nlm.nih.gov/pubmed/27036918)

Exam 1: Emergency Department