A 34-year-old man comes to the office due to a 5-month-history of exertional dyspnea without associated chest pain, palpitations, dizziness, or syncope. The patient recently emigrated from Brazil. Medical history is significant for an episode of megacolon, which was treated 2 years ago. On physical examination, there is 1+ pedal edema and mild jugular venous distension. Cardiac examination is significant for the presence of an S3. No murmurs are heard. Chest x-ray reveals prominent cardiomegaly. Which of the following is most likely causing his symptoms?

Question

A 34-year-old man comes to the office due to a 5-month-history of exertional dyspnea without associated chest pain, palpitations, dizziness, or syncope.  The patient recently emigrated from Brazil.  Medical history is significant for an episode of megacolon, which was treated 2 years ago.  On physical examination, there is 1+ pedal edema and mild jugular venous distension.  Cardiac examination is significant for the presence of an S3.  No murmurs are heard.  Chest x-ray reveals prominent cardiomegaly.  Which of the following is most likely causing his symptoms?

Quizplus · Accepted Answer

Explanation: This patient has Chagas disease, a chronic protozoal disease caused by Trypanosoma cruzi. The organism is common throughout South America and should be considered in a symptomatic patient who has recently emigrated from that area. The 2 primary manifestations of Chagas disease are: Megacolon/megaesophagus Cardiac disease Megacolon or megaesophagus (focal gastrointestinal [GI] dilatation) occur secondary to destruction of the nerves controlling the GI smooth muscle. This patient's pedal edema, jugular venous distension, S3, and cardiomegaly all point toward congestive heart failure. The pathophysiology of Chagas heart disease is not well understood but probably represents a prolonged myocarditis secondary to the protozoal infection. (Choice A) Diphtheria is unusual in present times because of widespread immunizations. Furthermore, diphtheria myocarditis is exceedingly rare. Upper respiratory tract symptoms would be expected. (Choice B) Coronary artery disease would be fairly unlikely in this young patient without risk factors for atherosclerosis. (Choice D) Giant cell myocarditis is a rare and frequently fatal form of myocarditis. The underlying pathophysiology is not well understood but likely involves autoimmunity. Patients with giant cell myocarditis tend to present with symptoms that are both more severe and more acute than those affecting the patient described here. (Choice E) Rickettsial infection can cause myocarditis, but megacolon would not be expected. Educational objective: Chagas disease is a chronic disease that can cause megaesophagus, megacolon, and/or cardiac dysfunction. The protozoan Trypanosoma cruzi, endemic to South America, is responsible.

A 34-Year-Old Man Comes to the Office Due to a 5-Month-History