View source for WBR0833

 {{WBRQuestion
|QuestionAuthor=Neeraja Danda M.B.B.S
|ExamType=USMLE Step 2 CK
|MainCategory=Internal medicine
|SubCategory=Cardiovascular, Infectious Disease
|MainCategory=Internal medicine
|SubCategory=Cardiovascular, Infectious Disease
|MainCategory=Internal medicine
|SubCategory=Cardiovascular, Infectious Disease
|MainCategory=Internal medicine
|MainCategory=Internal medicine
|SubCategory=Cardiovascular, Infectious Disease
|MainCategory=Internal medicine
|SubCategory=Cardiovascular, Infectious Disease
|MainCategory=Internal medicine
|SubCategory=Cardiovascular, Infectious Disease
|MainCategory=Internal medicine
|SubCategory=Cardiovascular, Infectious Disease
|MainCategory=Internal medicine
|MainCategory=Internal medicine
|SubCategory=Cardiovascular, Infectious Disease
|Prompt=A 40 year old male presents to the emergency department for difficulty breathing that started an hour prior and lasted for 15 minutes. Over the past 2 months he has experienced 3-4 similar episodes, which were brought on by exertion and relieved by rest. Other complaints include swelling of both feet and difficulty in swallowing. His past medical history is significant for hypertension and gout. He is an immigrant from Brazil and works as a security officer in the mall. His pulse rate is 72/min, and blood pressure is 100/70 mm hg. Cardiac auscultation reveals an S4 gallop. Electrocardiogram and cardiac enzymes are normal and echocardiography shows an ejection fraction of 50 percent. What is the most likely cause of this patient’s condition?
|Explanation=This patient describes episodes of dyspnea on exertion, pedal edema and dysphagia. Dyspnea and pedal edema with S4 gallop and a low ejection fraction on echocardiogram indicates heart failure or cardiomyopathy. This patient’s dysphagia and history of migration from a South American country like Brazil should raise suspicion for Chaga’s disease.  Chaga’s disease causes dilation of the heart chambers and the esophagus, which causes dilated cardiomyopathy and dysphagia respectively. Chagas disease is caused by a protozoan Trypanosoma Cruzi and transmitted by reduvid bug (kissing bug).

'''Educational Objective:''' Chagas disease characterized by dilated cardiomyopathy , mega esophagus and is most common in South American countries such as Brazil, Cuba, Mexico etc. It is caused by a protozoan Trypanosoma Cruzi and transmitted by Reduvid bug (kissing bug).

'''References:''' Page 93, 94 Master the boards step 2 CK second edition, http://www.wikidoc.org/index.php/Chagas_disease_overview  C.MichaelGibson,M.S.,M.D, http://en.wikipedia.org/wiki/Chagas_disease
|AnswerA=Myocardial infarction
	

|AnswerAExp='''Incorrect''' Normal electrocardiogram findings and normal levels of cardiac enzymes opposes the diagnosis of myocardial infarction. Both the S4 gallop, and heart failure symptoms strongly suggest cardiomyopathy.
|AnswerB=Hypertrophic obstructive cardiomyopathy
|AnswerBExp='''Incorrect''' Hypertrophic obstructive cardiomyopathy is a cause of diastolic dysfunction that causes sudden death in young athletes
|AnswerC=Trypanosoma Cruzi
|AnswerCExp=Chaga’s disease caused by Trypanosoma Cruzi is characterized by dilation of the heart chambers and the esophagus, which leads to dilated cardiomyopathy and dysphagia respectively
|AnswerD=Plasmodium Vivax
|AnswerDExp='''Incorrect''' Plasmodium vivax is a protozoan that causes malaria
|AnswerE=Entamoeba Histolytica
|AnswerEExp='''Incorrect''' Entamoeba is an anaerobic protozoan parasite that causes amebiasis.
|RightAnswer=C
|WBRKeyword=Chagas disease, Trypanosoma cruzi, Dilated cardiomyopathy, 
|Approved=Yes
}}