WBR0533

Author	[[PageAuthor::Yazan Daaboul, M.D. (Reviewed by Serge Korjian and Yazan Daaboul, M.D.)]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Pathophysiology
Sub Category	SubCategory::Cardiology
Prompt	[[Prompt::A 72-year-old man presents to the emergency department with progressive shortness of breath at rest. On admission, his heart rate is 90/min, blood pressure is 142/80 mmHg, and respiratory rate is 32/min. Physical examination is remarkable for a low-pitched extra heart sound appreciated in early diastole, prominent jugular vein, and bilateral pitting edema in the lower extremities. Which of the following statements is true regarding the patient's extra heart sound?]]
Answer A	AnswerA::The extra heart sound is a result of atrial contraction against a stiff ventricle
Answer A Explanation	AnswerAExp::S3 is heard due to increased filling pressure in a dilated ventricle. On the other hand, S4 is characterized by atrial contraction against a stiff ventricle.
Answer B	AnswerB::The extra heart sound conveys poor prognostic outcomes
Answer B Explanation	AnswerBExp::The presence of S3 is associated with a poor prognosis in patients with heart failure.
Answer C	AnswerC::The patient's symptoms are consistent with isolated left ventricular dysfunction
Answer C Explanation	[[AnswerCExp::The patient's syndrome, characterized by dyspnea, JVD, S3 on cardiac auscultation, and pitting edema, is consistent with left and right heart failure. JVD and pitting edema are important signs that implicate the involvement of the right side of the heart.]]
Answer D	AnswerD::The extra heart sound is commonly present in patients with aortic stenosis
Answer D Explanation	AnswerDExp::S4 is commonly present in patients with aortic stenosis.
Answer E	AnswerE::The extra heart sound is best heard at the base of the heart
Answer E Explanation	AnswerEExp::S3 is best heard at the apex of the heart; whereas S4 is best heard at the base of the heart.
Right Answer	RightAnswer::B
Explanation	[[Explanation::The patient in this scenario is presenting with symptoms consistent with heart failure. Physical examination of the patient reveals a third heart sound, S3, that is described as a low-pitched, early diastolic sound that is heard due to the increased filling pressure in a dilated ventricle. The patient also has jugular venous distention and pitting edema of the lower extremities, both of which signify the presence of right heart involvement. Elevation of the jugular venous pressure (JVP) and the presence of a third heart sound (S3) are 2 physical examination findings that are considered important prognostic features in patients with heart failure as they are associated with worse outcomes. Patients with S3 are more likely to have worse New York Heart Association (NYHA) functional class than those with absent S3 sound. Educational Objective: Presence of S3 is associated with worse outcomes in patients with heart failure. References: Rame JE, Dries DL, Drazner MH, et al. The prognostic value of the physical examination in patients with chronic heart failure. Congest Heart Fail. 2003;9(3):170-5, 178. First Aid 2014 page 270]]
Approved	Approved::Yes
Keyword	WBRKeyword::Heart failure, WBRKeyword::Jugular venous distention, WBRKeyword::JVD, WBRKeyword::Pitting edema, WBRKeyword::Third heart sound, WBRKeyword::S3, WBRKeyword::Prognosis, WBRKeyword::Congestive heart failure, WBRKeyword::NYHA, WBRKeyword::Physical exam
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