A 34-year-old immigrant from Brazil comes to the physician with 2 months of palpitations accompanied by lightheadedness. He also complains of mild shortness of breath. The patient suffers from moderate, persistent asthma and takes daily inhaled glucocorticoid and salmeterol. He received "most of the childhood immunizations." He has no family history of heart disease or sudden cardiac death.
The patient's blood pressure is 122/70 mm Hg and pulse is 82/min. Estimated jugular venous pressure is normal. The apical impulse is displaced to the left. A soft 2/6 holosystolic murmur is heard at the apex. Lungs are clear on auscultation. There is no organomegaly, skin rash, or peripheral edema.
Electrocardiogram shows normal sinus rhythm with right bundle branch block. Echocardiogram shows a left ventricular apical aneurysm and left ventricular ejection fraction of 35%. Cardiac catheterization shows normal coronary arteries.
Which of the following is most likely responsible for this patient's condition?

Question

A 34-year-old immigrant from Brazil comes to the physician with 2 months of palpitations accompanied by lightheadedness.  He also complains of mild shortness of breath.  The patient suffers from moderate, persistent asthma and takes daily inhaled glucocorticoid and salmeterol.  He received "most of the childhood immunizations."  He has no family history of heart disease or sudden cardiac death.
The patient's blood pressure is 122/70 mm Hg and pulse is 82/min.  Estimated jugular venous pressure is normal.  The apical impulse is displaced to the left.  A soft 2/6 holosystolic murmur is heard at the apex.  Lungs are clear on auscultation.  There is no organomegaly, skin rash, or peripheral edema.
Electrocardiogram shows normal sinus rhythm with right bundle branch block.  Echocardiogram shows a left ventricular apical aneurysm and left ventricular ejection fraction of 35%.  Cardiac catheterization shows normal coronary arteries.
Which of the following is most likely responsible for this patient's condition?

Quizplus · Accepted Answer

This patient has the classic clinical presentation of chronic Chagas cardiomyopathy, which is caused by a protozoan infection from Trypanosoma cruzi. The natural history of Chagas disease has 3 distinct phases. The first is an acute phase of mild, nonspecific symptoms with fever or myalgias, followed by an indeterminate phase with serologic or parasitic evidence of T cruzi infection in the absence of symptoms or signs of infection. The final phase is chronic Chagas cardiomyopathy. Chronic Chagas cardiomyopathy is the leading cause of dilated cardiomyopathy in Central and South America. Patients can remain asymptomatic for several years or develop symptoms of heart failure. Echocardiogram shows varying degrees of right and/or left ventricular systolic dysfunction, along with left ventricular apical aneurysm, which is considered pathognomonic of Chagas cardiomyopathy. (Choice A) Blastomycosis is a systemic granulomatous infection usually involving the lungs that causes acute or chronic pneumonia. It can also involve extrapulmonary sites including skin (verrucous lesions, subcutaneous nodules), bone (osteomyelitis), and the genitourinary tract (prostatitis, epididymo-orchitis). (Choice B) Lyme carditis caused by disseminated Borrelia burgdorferi typically presents with atrioventricular conduction block. Cardiomyopathy is extremely rare and has not been reported in the United States. (Choice C) Dengue virus infection has degrees of clinical presentation ranging from a mild self-limiting febrile illness to dengue hemorrhagic fever with shock syndrome. Chronic cardiomyopathy is not seen with Dengue fever. (Choice D) Leishmania donovani causes visceral leishmaniasis (also known as kala-azar), which is characterized by insidious onset and progression of fever, malaise, weight loss, and splenomegaly. Educational objective: Chagas disease is the leading cause of dilated cardiomyopathy in Central and South America. It is caused by Trypanosoma cruzi infection and is characterized by myocarditis progressing to dilated cardiomyopathy, nonspecific electrocardiogram abnormalities including right bundle branch block and left anterior fascicular block, and development of left ventricular apical aneurysms. __________ References: Chagas disease: an overview of clinical and epidemiological aspects. (http://www.ncbi.nlm.nih.gov/pubmed/23770163)

A 34-Year-Old Immigrant from Brazil Comes to the Physician with 2