WBR0042

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Author PageAuthor::Gonzalo Romero
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Pathology
Sub Category SubCategory::Cardiology
Prompt [[Prompt::A 21-year-old healthy male college student is concerned about a final he has to take next week. The grade on this exam could compromise his scholarship if he does not pass. He has been playing football since high school and plays in the College Football team. The next week they are going to have the school Football finale, which will decide if the local college qualifies to go to State competition. He has decent grades in school and has many friends. The following week he takes his exam. The following day the game starts with a lot of cheering and energy from the audience and players, because this is a decisive game. He is excited and tries to perform his best on the field. While jogging after catching the ball, he falls onto the ground. At first he appeared to have hurt his knee while running. The game is stopped. The coach and teammates find him unresponsive and try their best to help him. After several minutes laying on the ground, the EMS arrive to the scene and find him without vitals. They start CPR immediately and take him to the nearest Hospital where they run the ACLS protocol without any success. An autopsy is scheduled due to the uncertainty of his cause of death. Which of the following Macroscopic or Microscopic changes is most specific for the most likely diagnosis?]]
Answer A AnswerA::Symmetric left ventricular hypertrophy
Answer A Explanation [[AnswerAExp::Incorrect. Symmetric left ventricular hypertrophy is characteristically present in patients with increased afterload, such as aortic stenosis or hypertension, which leads to increased synthesis of actin and myosin which are arranged in a "organized fashion". Ultimately the patient develops diastolic dysfunction due to the inability of the heart to fill in with blood during diastole.]]
Answer B AnswerB::White appearance of the endocardium
Answer B Explanation [[AnswerBExp::Incorrect. This can be present in Endocardial fibroelastosis, a rare restrictive cardiomyopathy present in young children less than 2 years old. It is due to an excessive fibrosis of the endocardium that causes diastolic dysfunction.]]
Answer C AnswerC::Cardiomyocytes hypertrophy in an organized fashion
Answer C Explanation [[AnswerCExp::Incorrect. This corresponds with the hypertrophy seen in patients with increased afterload, such as aortic stenosis or hypertension.]]
Answer D AnswerD::Prominent ventricular septum hypertrophy compared to the ventricular wall
Answer D Explanation [[AnswerDExp::Correct.]]
Answer E AnswerE::Fibrotic thickening of endocardium and valves of the right side of the heart
Answer E Explanation [[AnswerEExp::Incorrect. This is the macroscopic description of an endocardium affected by a carcinoid syndrome due to chronic serotonin exposure, which causes fibrosis of the tricuspid valve and pulmonary valve. It is present when the carcinoid tumor metastasize to the liver. The patient clinically presents with diarrhea, wheezing, telangiectasias, flushing of the skin and cramping.]]
Right Answer RightAnswer::D
Explanation [[Explanation::This young athlete presents with a sudden death during intense exercise due to ventricular arrhythmias, a typical clinical presentation of Hypertrophic cardiomyopathy, hypertrophic obstructive cardiomyopathy (HOCM), also known as asymmetrical septal hypertrophy or idiopathic hypertrophic subaortic stenosis (IHSS). Commonly causes sudden death in young athletes. It can be autosomal dominant or idiopathic.
  1. Macroscopically the heart shows hypertrophy more prominent in the ventricular septum, obstructing the outflow from the left ventricle. The ventricular cavity acquires a banana shaped appearance.
  2. Histologically there are hypertrophied cardio-myocytes in disarray which alters the conduction system leading to arrhythmias.


Educational Objective: Hypertrophic Obstructive Cardiomyopathy (HOCM) is a common cause of sudden death in young athletes during intense exercise
Educational Objective:
References: ]]

Approved Approved::Yes
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