WBR0042

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 playing in a football finale game across local colleges when he suddenly falls on the ground while running. The player is found unresponsive. The Emergency Medical Services arrive promptly and initiate CPR and resuscitation measures without success. According to his family and friends, he has always been healthy and he has been playing football since high school. Autopsies are obtained in order to determine the cause of death. Which of the following cardiac macroscopic or microscopic changes is most likely present?]]
Answer A	AnswerA::Symmetric left ventricular hypertrophy
Answer A Explanation	[[AnswerAExp::Symmetric left ventricular hypertrophy is characteristically present in patients with increased afterload, such as aortic stenosis or hypertension. This leads to the increased synthesis of actin and myosin that 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::A white appearance of the endocardium 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::Cardiomyocytes hypertrophy in an organized fashion is present among 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::Prominent ventricular septum hypertrophy is a characteristic finding of hypertrophic cardiomyopathy.]]
Answer E	AnswerE::Fibrotic thickening of the endocardium and the valves of the right side of the heart
Answer E Explanation	[[AnswerEExp::Fibrotic thickening of the endocardium and the valves of the right side of the heart 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. Carcinoid syndrome occurs when the carcinoid tumor metastasize to the liver. The patient clinically presents with diarrhea, wheezing, telangiectasias, and flushing of the skin.]]
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, also known as hypertrophic obstructive cardiomyopathy (HOCM), asymmetrical septal hypertrophy or idiopathic hypertrophic subaortic stenosis (IHSS). Hypertrophic cardiomyopathy can be either autosomal dominant or idiopathic. Macroscopically the heart shows hypertrophy more prominent in the ventricular septum, obstructing the outflow from the left ventricle. The ventricular cavity acquires a banana shape appearance. Histologically there are hypertrophied cardiomyocytes in disarray which alters the conduction system and subsequently predisposes to arrhythmias. Educational Objective: Hypertrophic obstructive cardiomyopathy (HOCM) is a common cause of sudden death in young athletes during intense exercise. It is characterized by the presence of cardiac hypertrophy more prominent in the ventricular septum and hypertrophied cardiomyocytes in disarray. References: ]]
Approved	Approved::Yes
Keyword	WBRKeyword::Cardiology, WBRKeyword::Pathology, WBRKeyword::Hypertrophic cardiomyopathy, WBRKeyword::HOCM
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::

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