WBR0042: Difference between revisions

Jump to navigation Jump to search
No edit summary
m (refreshing WBR questions)
 
(11 intermediate revisions by 4 users not shown)
Line 1: Line 1:
{{WBRQuestion
{{WBRQuestion
|QuestionAuthor=Gonzalo Romero
|QuestionAuthor=Gonzalo Romero (Reviewed by Rim Halaby and Yazan Daaboul)
|ExamType=USMLE Step 1
|ExamType=USMLE Step 1
|MainCategory=Pathology
|MainCategory=Pathology
|SubCategory=Cardiology
|SubCategory=Cardiology
|MainCategory=Pathology
|Prompt=A 21-year-old male college student suddenly loses consciousness and falls while playing football. The player is unresponsive to verbal or physical stimuli, and has an undetectable pulse. Despite CPR and resuscitation efforts, the patient dies.  According to his family and friends, the patient has always been healthy and has been playing soccer since high school. Further history reveals that two of the patient's relatives also died the same way. Autopsy is obtained in order to determine the cause of death. Which of the following cardiac changes is most likely present in this patient?
|SubCategory=Cardiology
|Explanation=This young athlete presents with [[sudden cardiac death]] during intense exercise due to [[ventricular arrhythmias]], a typical clinical presentation of [[hypertrophic obstructive cardiomyopathy]] (HOCM). HOCM is a genetic disorder caused by a missense mutation that encodes sarcomere proteins of the heart. It is relatively common, occurring in approximately 1 of every 500 adults.
|MainCategory=Pathology
 
|SubCategory=Cardiology
*Macroscopically, the heart demonstrates [[hypertrophy]] more prominent in the ventricular septum, obstructing the outflow from the [[left ventricle]]. Additional complications of the observed hypertrophy include mitral regurgitation due to systolic anterior motion (SAM) of the mitral valve, systolic and diastolic dysfunction, myocardial ischemia, and fatal ventricular arrhythmias.
|MainCategory=Pathology
 
|MainCategory=Pathology
*Histologically, there are hypertrophied [[cardiomyocytes]] in disarray that alter the conduction system and subsequently predispose to [[arrhythmias]].  
|SubCategory=Cardiology
 
|MainCategory=Pathology
HOCM should be suspected based on physical exam findings and abnormal findings on echocardiogram or even ECG. On physical exam, a systolic ejection murmur is typically heard at the left sternal border. The intensity of the murmur characteristically increases as preload decreases. Decreasing preload may be performed by changing the patient's position from a seated or squatting position to a standing position. Ultrasound is the diagnostic test of choice, demonstrating asymmetric myocardial hypertrophy with septal thickness greater than the thickness of the free wall.
|SubCategory=Cardiology
 
|MainCategory=Pathology
The mainstay of HOCM therapy includes symptomatic relief and prevention of occurrence of arrhythmias, which may be the cause of death in these patients. Although the risk of death is less than 1% per year, young athletes with HOCM are specifically at risk of developing ventricular arrhythmias and death.
|SubCategory=Cardiology
 
|MainCategory=Pathology
Other members of the family should also be included in the management plan. Immediate family members should be requested to perform periodic ultrasound because hypertrophy may become evident as late as 60 - 70 years of age.
|SubCategory=Cardiology
|MainCategory=Pathology
|MainCategory=Pathology
|SubCategory=Cardiology
|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?
|Explanation=This young athlete presents with [[sudden cardiac 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 demonstrates [[hypertrophy]] more prominent in the ventricular septum, obstructing the outflow from the [[left ventricle]]. The ventricular cavity acquires a banana shape appearance. [[File:2369.jpg|center|200px]]
#'''Histologically''' there are hypertrophied [[cardiomyocytes]] in disarray which alters the conduction system and subsequently predisposes to [[arrhythmias]]. [[File:438.jpg|center|200px]]
|AnswerA=Symmetric left ventricular hypertrophy
|AnswerA=Symmetric left ventricular hypertrophy
|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]].
|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]], which are normally arranged in a "organized fashion".  Ultimately, these patients develop diastolic dysfunction due to the inability of the heart to fill in with blood during [[diastole]].
|AnswerB=White appearance of the endocardium
|AnswerB=White appearance of the endocardium
|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 caused by the excessive [[fibrosis]] of the [[endocardium]] that causes diastolic dysfunction. Shown below is an image depicting an autopsy of a heart affected with [[endocardial fibroelastosis]].
|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 of age. It is caused by excessive [[fibrosis]] of the [[endocardium]] that causes diastolic dysfunction.
 
|AnswerC=Cardiomyocyte hypertrophy in an organized fashion
[[Image:Endocardial_fibroelastosis_2.jpg|center|200px]]
|AnswerCExp=Cardiomyocyte [[hypertrophy]] in an organized fashion is found among patients with increased [[afterload]] such as [[aortic stenosis]] or [[hypertension]].
|AnswerC=Cardiomyocytes hypertrophy in an organized fashion
|AnswerCExp=Cardiomyocytes [[hypertrophy]] in an organized fashion is present among patients with increased [[afterload]] such as [[aortic stenosis]] or [[hypertension]].
|AnswerD=Prominent ventricular septum hypertrophy
|AnswerD=Prominent ventricular septum hypertrophy
|AnswerDExp=Prominent ventricular septum [[hypertrophy]] is a characteristic finding of [[hypertrophic cardiomyopathy]].
|AnswerDExp=Prominent ventricular septum [[hypertrophy]] is a characteristic finding of [[hypertrophic cardiomyopathy]].
|AnswerE=Fibrotic thickening of the endocardium and the valves of the right side of the heart
|AnswerE=Fibrotic thickening of the endocardium and the valves of the right side of the heart
|AnswerEExp=[[Fibrosis|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|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.
|AnswerEExp=[[Fibrosis|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|carcinoid syndrome]] due to chronic [[serotonin]] exposure, which causes fibrosis of the tricuspid and pulmonary valves. [[Carcinoid syndrome]] occurs when the [[carcinoid tumor]] metastasizes to the liver, thereby bypassing the first-pass metabolism of the liver. These patients present with [[diarrhea]], [[wheezing]], [[telangiectasias]], and [[flushing]] of the skin.
|EducationalObjectives=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.
|EducationalObjectives=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 presence of hypertrophied [[cardiomyocytes]] in disarray.
|References=Nishimura, RA; Holmes, DR. Hypertrophic obstructive cardiomyopathy. N Engl J Med. 2004;350:1320-1327.
First Aid 2014 page 290
|RightAnswer=D
|RightAnswer=D
|WBRKeyword=Cardiology, Pathology, Hypertrophic cardiomyopathy, HOCM
|WBRKeyword=Cardiology, Pathology, Hypertrophic cardiomyopathy, HOCM, HCM, Ischemia, Sudden death, Cardiomyopathy,
|Approved=Yes
|Approved=Yes
}}
}}
{{WBRImage}}
{{WBRImage}}

Latest revision as of 23:08, 27 October 2020

 
Author PageAuthor::Gonzalo Romero (Reviewed by Rim Halaby and Yazan Daaboul)
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Pathology
Sub Category SubCategory::Cardiology
Prompt [[Prompt::A 21-year-old male college student suddenly loses consciousness and falls while playing football. The player is unresponsive to verbal or physical stimuli, and has an undetectable pulse. Despite CPR and resuscitation efforts, the patient dies. According to his family and friends, the patient has always been healthy and has been playing soccer since high school. Further history reveals that two of the patient's relatives also died the same way. Autopsy is obtained in order to determine the cause of death. Which of the following cardiac changes is most likely present in this patient?]]
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, which are normally arranged in a "organized fashion". Ultimately, these patients develop 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 of age. It is caused by excessive fibrosis of the endocardium that causes diastolic dysfunction.]]
Answer C AnswerC::Cardiomyocyte hypertrophy in an organized fashion
Answer C Explanation [[AnswerCExp::Cardiomyocyte hypertrophy in an organized fashion is found among patients with increased afterload such as aortic stenosis or hypertension.]]
Answer D AnswerD::Prominent ventricular septum hypertrophy
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 and pulmonary valves. Carcinoid syndrome occurs when the carcinoid tumor metastasizes to the liver, thereby bypassing the first-pass metabolism of the liver. These patients present with diarrhea, wheezing, telangiectasias, and flushing of the skin.]]
Right Answer RightAnswer::D
Explanation [[Explanation::This young athlete presents with sudden cardiac death during intense exercise due to ventricular arrhythmias, a typical clinical presentation of hypertrophic obstructive cardiomyopathy (HOCM). HOCM is a genetic disorder caused by a missense mutation that encodes sarcomere proteins of the heart. It is relatively common, occurring in approximately 1 of every 500 adults.
  • Macroscopically, the heart demonstrates hypertrophy more prominent in the ventricular septum, obstructing the outflow from the left ventricle. Additional complications of the observed hypertrophy include mitral regurgitation due to systolic anterior motion (SAM) of the mitral valve, systolic and diastolic dysfunction, myocardial ischemia, and fatal ventricular arrhythmias.
  • Histologically, there are hypertrophied cardiomyocytes in disarray that alter the conduction system and subsequently predispose to arrhythmias.

HOCM should be suspected based on physical exam findings and abnormal findings on echocardiogram or even ECG. On physical exam, a systolic ejection murmur is typically heard at the left sternal border. The intensity of the murmur characteristically increases as preload decreases. Decreasing preload may be performed by changing the patient's position from a seated or squatting position to a standing position. Ultrasound is the diagnostic test of choice, demonstrating asymmetric myocardial hypertrophy with septal thickness greater than the thickness of the free wall.

The mainstay of HOCM therapy includes symptomatic relief and prevention of occurrence of arrhythmias, which may be the cause of death in these patients. Although the risk of death is less than 1% per year, young athletes with HOCM are specifically at risk of developing ventricular arrhythmias and death.

Other members of the family should also be included in the management plan. Immediate family members should be requested to perform periodic ultrasound because hypertrophy may become evident as late as 60 - 70 years of age.
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 presence of hypertrophied cardiomyocytes in disarray.
References: Nishimura, RA; Holmes, DR. Hypertrophic obstructive cardiomyopathy. N Engl J Med. 2004;350:1320-1327. First Aid 2014 page 290]]

Approved Approved::Yes
Keyword WBRKeyword::Cardiology, WBRKeyword::Pathology, WBRKeyword::Hypertrophic cardiomyopathy, WBRKeyword::HOCM, WBRKeyword::HCM, WBRKeyword::Ischemia, WBRKeyword::Sudden death, WBRKeyword::Cardiomyopathy
Linked Question Linked::
Order in Linked Questions LinkedOrder::


Image [[WBRImage::|]] Caption WBRImageCaption::no-display Position [[WBRImagePlace::|]]