WBR0997

Author	[[PageAuthor::Mohamed Moubarak, M.D. [1]]]
Exam Type	ExamType::USMLE Step 3
Main Category	MainCategory::Emergency Room
Sub Category	SubCategory::Cardiovascular
Prompt	[[Prompt::A 62 year-old man comes to ED complaining of acute shortness of breath, fatigue, and worsening exertional dyspnea. He hardly can talk, and mentioned waking up several times at night on sever cough with frothy sputum. He used to sleep on two pillows but now he is using three. The patient has past medical history of hypertension for 15 years, and diabetes mellitus for 20 years. On examination, his BP 90/70, pulse 120, respiratory rate 28, and temperature is 36.9 C (98.5F). Chest examination revealed decreased breath sounds and dullness at both bases with bibasilar rales. Cardiac examination revealed diffuse, laterally and inferiorly displaced apex, with distant heart sounds and S3 gallop. There is a jugular venous distention, with JVP of 12 cm, and oxygen saturation of 83%. Extremities are cool and show 2+ pitting edema in both legs up to the knees. Which test would be most sensitive for the diagnosis of this condition?]]
Answer A	AnswerA::CK-MB
Answer A Explanation	[[AnswerAExp::Incorrect Cardiac enzymes are neither sensitive nor specific for CHF diagnosis]]
Answer B	AnswerB::LDH
Answer B Explanation	[[AnswerBExp::Incorrect Cardiac enzymes are neither sensitive nor specific for CHF diagnosis]]
Answer C	AnswerC::brain natriuretic peptide (BNP)
Answer C Explanation	[[AnswerCExp::Correct BNP test has been found to be both sensitive and specific for the diagnosis of CHF]]
Answer D	AnswerD::Chest x-ray
Answer D Explanation	[[AnswerDExp::Incorrect Chest x-ray can determine the presence of pulmonary edema but not its cause.]]
Answer E	AnswerE::Troponin I
Answer E Explanation	[[AnswerEExp::Incorrect Cardiac enzymes are neither sensitive nor specific for CHF diagnosis]]
Right Answer	RightAnswer::C
Explanation	[[Explanation::The BNP test has been found to be both sensitive and specific for the diagnosis of CHF. It can be a very useful test to order when a patient is dyspneic to help to determine if CHF is the cause. Troponin, CK-MB, and LDH are markers of damage to cardiac muscle. Cardiac enzymes are neither sensitive nor specific for CHF. Similarly, a CXR can determine the presence of pulmonary edema but not its cause. Related to WBR0996 Educational Objective: References: ]]
Approved	Approved::No
Keyword	[[WBRKeyword::Pulmonary edema]]
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::